Journal articles: 'Martensitic (M) steel'

1

Kubler, R., M. Berveiller, M. Cherkaoui, and K. Inal. "Transformation Textures in Unstable Austenitic Steel." Journal of Engineering Materials and Technology 125, no. 1 (December 31, 2002): 12–17. http://dx.doi.org/10.1115/1.1525249.

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During the martensitic transformation in elastic-plastic materials, the local transformation strain as well as the plastic flow inside austenite are strongly related with the crystallographic orientation of the austenitic lattice. Two mechanisms involved in these materials, i.e., plasticity by dislocation motion and martensitic phase formation are coupled through kinematical constraints so that the lattice spin of the austenitic grains is different from the one due to classical slip. In this work, the lattice spin ω˙eA of the austenitic grains is related with the slip rate on the slip systems of the two phases, γ˙A and γ˙M, the evolution of the martensite volume fraction f˙ and the overall rotation rate Ω˙ of the grains. This new relation is integrated in a micromechanical model developed for unstable austenite in order to predict the evolution of the austenite texture during TRansformation Induced Plasticity (TRIP). Results for the evolution of the lattice orientation during martensitic transformation are compared with experimental data obtained by X-ray diffraction on a 304 AISI steel.

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Lei, Tian, Guan Hong Kong, Xue Ying Cui, Rui Feng, and Sheng Li Li. "The Properties and Structure Stability of Martensite-Bainite Dual Phase Structure in Bearing Steel." Applied Mechanics and Materials 330 (June 2013): 8–11. http://dx.doi.org/10.4028/www.scientific.net/amm.330.8.

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The Martensite-Bainite (M/B) dual phase structure has excellent combined processing properties which can be applied to the bearing steel. Frequently, the service conditions of rolling mill bearings are so harsh that the organization and performance of the bearing materials may change during the using process. The study of structural stability of martensite-bainite dual phase structure is extremely essential. This paper determined the superiority of Martensite-Bainite (M/B) dual phase structure applied to G55SiMoV by contrasting the properties of single martensite and M/B dual phase structure. temper resistance is discussed by testing the change of organization and performance after temper.The results show that the combination property of the M/B dual phase structure are better than the martensitic structure. The G55SiMoV steel with martensite-bainite dual phase structure has a greater temperature range to ensure the tempering stability.

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Kaede, K., A. Jäger, V. Gärtnerová, C. Takushima, T. Yamamuro, and S. Tsurekawa. "Measurement of Local Mechanical Properties of T91 Steel Corroded by Molten Lead-Bismuth Eutectic Alloy via Micropillar Compression Test." MRS Advances 3, no. 8-9 (2018): 419–25. http://dx.doi.org/10.1557/adv.2018.36.

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ABSTRACTT91 ferritic/martensitic (F/M) steel is an expected structural material candidate for Gen IV liquid lead-bismuth cooled nuclear reactors. However, molten lead-bismuth eutectic alloy (mLBE) often causes liquid-metal embrittlement (LME) of F/M steels. Although prior austenite grain boundaries and martensite block boundaries were reported to be preferential sites for LME, the mechanism of LME in a T91/LBE couple is yet to be comprehensively understood. In this paper, the effect of mLBE on T91 steel was investigated using micropillar compression tests. mLBE corrosion was found to cause a significant decrease in yield stress. The micropillar made from mLBE-corroded specimen was significantly sheared along high angle boundaries. In addition, EDS analysis demonstrated the presence of Pb/Bi at these high angle boundaries.

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Prijanovič, Urban, Marica Prijanovič Tonkovič, Uroš Trdan, Matej Pleterski, Matija Jezeršek, and Damjan Klobčar. "Remote Fibre Laser Welding of Advanced High Strength Martensitic Steel." Metals 10, no. 4 (April 20, 2020): 533. http://dx.doi.org/10.3390/met10040533.

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The study presents the results of remote robotic laser welding of advanced high strength Docol® 1200 M martensitic steel. One mm thick samples were welded in a lap joint configuration using a special clamping system. Welding was done using a continuous-wave (CW) fibre laser with a constant welding power of 300 W and constant focus diameter Ø 1.8 mm. Welding was done using 12 different welding speeds in the range from 0.15 to 1 m/min, whereas the inclination angle was kept constant at 0°. The influence of various welding speeds and linear heat inputs during welding on microstructural changes were examined by the occurrence of acicular and allotriomorphic ferrite or martensite. Results revealed big influence of the clamping system on the accumulation of the laser beam energy, heat sink and consequently weld size and geometry, as well as its microstructure and joint strength. Tensile-shear strength, microstructure and hardness results confirmed laser power of 300 W and 0.6 m/min welding speed as the optimal parameters, at which a martensitic structure was obtained in the weld. The width of the heat affected zone (HAZ) in this case is 1100 μm.

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Golański, Grzegorz, and Paweł Wieczorek. "Microstructural Investigation of the Ferritic GX12CrMoVNbN9-1 (GP91) Cast Steel." Solid State Phenomena 186 (March 2012): 287–91. http://dx.doi.org/10.4028/www.scientific.net/ssp.186.287.

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The paper presents research on the microstructure of high chromium martensitic GX12CrMoVNbN9-1 (GP91) cast steel. The steel was subject to investigation in the as-cast state, after hardening as well as after quenching and tempering. The microstructure and morphology of precipitates in GP91 cast steel was examined in terms of changes taking place during the technological process. It has been shown that the examined cast steel is characterized by a microstructure of lath martensite (and polygonized ferrite) with numerous precipitates, such as: M3C, M23C6 and MX (NbC, VX) of diverse morphology. Tempered martensite in the cast steel consists of former austenite grains separated by high angle grain boundaries. These grains are subdivided by high angle boundaries into blocks of martensite laths. The dislocation density of the tempered martensite is high (of about 1014 m-2).

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Bubnoff, Dimitry V., Mariana M. O. Carvalho, José Adilson de Castro, and Thiago R. M. Lourenço. "Kinetic Study on Martensite Formation in Steels 1045 and 4340 under Variable Cooling Rates." Materials Science Forum 869 (August 2016): 550–55. http://dx.doi.org/10.4028/www.scientific.net/msf.869.550.

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The experiments were carried with two steels with different chemical compositions, aiming at understanding and comparison with the available literature. The microstructures of steels 1045 and 4340 were characterized and quantified using scanning electron microscopy (SEM) and optic microscopy (OM) with quantitative methods. Based on the experimental results, the amount of martensite, the hardness and the microhardness were determined, as a function of the distance from the quenching end, under different cooling conditions. For predicting the evolution of martensitic fraction along the sample, Koistinen-Marburger’s (K-M) model was adopted. It was found that the parameters recommended in the literature for the traditional K-M model do not represent accurately the results obtained for the steel samples under investigation. According to indications found in recent literature, parameter corrections were proposed, leading to a modified K-M model which better represents the transformations observed in the different examined steels.

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Harjo, Stefanus, Takuro Kawasaki, Yo Tomota, and Wu Gong. "Unusual Plastic Deformation Behavior in Lath Martensitic Steel Containing High Dislocation Density." Materials Science Forum 905 (August 2017): 46–51. http://dx.doi.org/10.4028/www.scientific.net/msf.905.46.

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To understand the strengthening mechanism of a metallic material with high dislocation density, the plastic deformation behavior of lath martensite was studied by means of in situ neutron diffraction measurements during tensile deformations using a 22SiMn2TiB steel and a Fe-18Ni alloy. The characteristics of dislocation were analyzed and were discussed with the relation of stress-strain curves. The dislocation densities (ρ) induced by martensitic transformation during heat-treatment in both materials were found to be originally as high as 1015 m-2 order, and subsequently to increase slightly by the tensile deformation. The parameter M value which displays the dislocation arrangement dropped drastically at the beginning of plastic deformation in both materials, indicating that the random arrangement became more like a dipole arrangement.

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Pioszak, Greger L., and Richard P. Gangloff. "Hydrogen Environment Assisted Cracking of a Modern Ultra-High Strength Martensitic Stainless Steel." Corrosion 73, no. 9 (May 8, 2017): 1132–56. http://dx.doi.org/10.5006/2437.

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A modern martensitic stainless steel (Ferrium® PH48S™) resists hydrogen environment assisted cracking (HEAC) in aqueous NaCl at ultra-high yield strengths (1,400 MPa to 1,600 MPa). HEAC is transgranular, because of increased steel purity and La addition, compared to severe intergranular HEAC in Custom® 465-H900 without rare earth elements. Minimum threshold for HEAC (KTH) is low (8 MPa√m to 17 MPa√m) for each steel under substantial cathodic polarization. Transgranular HEAC occurs along martensite packet and {110}α′-block interfaces in PH48S, likely a result of H decohesion enabled by localized plasticity. Martensite transformation produces a large area of coincident site lattice interfaces in the refined microstructure of PH48S. However, a susceptible network of random packet/block interfaces is connected in 3D to limit interface engineering. Nanoscale strengthening precipitates in PH48S reduce effective H diffusivity to the mid-10−10 cm2/s range, because of reversible H trapping with a binding energy of 12 kJ/mol. This diffusivity reduces the Stage II growth rate by 1 to 3 orders of magnitude compared to C465 and carbide strengthened ultra-high strength steels. PH48S and C465 are nearly immune to HEAC when cathodically polarized by 50 mV to 500 mV, attributed to a minimum in occluded-crack tip overpotential for H production. The breadth of this protective-potential window increases with decreasing steel strength. Increased Cr does not degrade HEAC resistance, suggesting that crack passivity dominates cation acidification to reduce H production and/or uptake. A quantitative decohesion model effectively predicts the potential dependence of da/dtII using crack tip H solubility reverse calculated from a KTH model.

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El-Tahawy, Moustafa, Jenő Gubicza, Yi Huang, Hye Lim Choi, Hee Man Choe, János L. Lábár, and Terence G. Langdon. "The Influence of Plastic Deformation on Lattice Defect Structure and Mechanical Properties of 316L Austenitic Stainless Steel." Materials Science Forum 885 (February 2017): 13–18. http://dx.doi.org/10.4028/www.scientific.net/msf.885.13.

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The effect of different plastic deformation methods on the phase composition, lattice defect structure and hardness in 316L stainless steel was studied. The initial coarse-grained γ-austenite was deformed by cold rolling (CR) or high-pressure torsion (HPT). It was found that the two methods yielded very different phase compositions and microstructures. Martensitic phase transformation was not observed during CR with a thickness reduction of 20%. In γ-austenite phase in addition to the high dislocation density (~10 × 1014 m-2) a significant amount of twin-faults was detected due to the low stacking fault energy. On the other hand, γ-austenite was gradually transformed into ε and α’-martensites with transformation sequences γ→ε→α’ during HPT deformation. A large dislocation density (~133 × 1014 m-2) was detected in the main phase (α’-martensite) at the periphery of the disk after 10 turns of HPT. The high defect density is accompanied by a very small grain size of ~45 nm in the HPT-processed sample, resulting in an very large hardness of 6130 MPa.

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Zhou, Xiao Ling, Yin Zhong Shen, Tian Tian Shi, Bo Ji, and Zhi Qiang Xu. "Identification of M₆C Carbides Forming during Short-Term Creep in 11Cr-3W-3CoVNbTaNd Ferritic/Martensitic Steel." Solid State Phenomena 298 (October 2019): 3–12. http://dx.doi.org/10.4028/www.scientific.net/ssp.298.3.

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M6C carbides were found to form during short-term creep tests at 600 °C for 1100 h in an 11Cr ferritic/martensitic (F/M) steel with the normalized and tempered condition. The M6C carbides have a face-centered cubic crystal structure, and a metallic element composition of 41-45Fe, 30-33W, 19-21Cr, 3Co/5Ta in atomic pct. The M6C carbides were a dominant phase in the crept steel. δ-ferrite in high-Cr F/M steels may lead to a premature formation of large-sized M6X precipitates during high temperature creep.

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11

Mou, Yang, Li Hong Xue, Qi Lai Zhou, Cai Xuan Lu, and You Wei Yan. "Effect of Strain on Microstructures and Mechanical Properties of Warmly Deformed SCRAM Steel for Fusion Application." Advanced Materials Research 941-944 (June 2014): 1463–68. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.1463.

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The SCRAM steel was processed by warm deformation on Gleeble-3500 thermo-simulation machine. The effect of strain on the microstructures and mechanical properties of SCRAM steel was investigated. The results show that an increase in the strain can result in refining the martensitic laths, increasing the volume fraction of precipitates and the dislocation density in SCRAM steel. The martensitic lath width decreases from 0.83 μm to 0.48 μm and the dislocation density increases from 1.3 × 1015 m-2 to 6.4 × 1015 m-2 in SCRAM steel. The specimen exhibits high ultimate tensile strength and yield strength but low reduction of area and total elongations when the strain (ε) is up to 0.5. The tensile fracture surface observation indicates that dimples become smaller and shallower while tear ridges drastically grow up with the strain increasing.

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12

Wirths, Vera, Rainer Wagener, Wolfgang Bleck, and Tobias Melz. "Bainitic Forging Steels for Cyclic Loading." Advanced Materials Research 922 (May 2014): 813–18. http://dx.doi.org/10.4028/www.scientific.net/amr.922.813.

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Light-weight design is one of the main drivers for material development in the automotive industry. For optimum weight reduction new materials and their fatigue behavior under real cyclic service loads have to be taken into account (Gassner test). Currently the casted components made from Austempered Ductile Iron (ADI) show better service fatigue life for variable load cases than some traditional forging steels because of it’s inherent retained austenite. The traditional forging steels are the precipitation hardening ferritic-pearlitic steels (PHFP steel) and the martensitic quenched and tempered (Q&T) steels. The next steel generation for forged components in the drive train might be bainitic steels with an optimized microstructure with respect to cyclic behavior. Depending on the chemical composition and the heat treatment it includes a ferritic primary phase and a secondary phase, which consists of either carbides, martensite, retained austenite or M/A constituents. By alloying of more than 1% Si the formation of cementite will be suppressed and a carbide free bainite (CFB) will be formed. The secondary phase of this CFB contains retained austenite, which has the possibility to close crack tips by local compression stresses due to the transformation to martensite. As a result of this CFB exhibits better cyclic properties than the commonly used forging steels. The materials and process design as well as results of the fatigue behavior will be presented.

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Xu, Zhi Qiang, Yin Zhong Shen, Peng Cheng Zhu, and Wen Wen Liu. "Precipitate Phases in Normalized Ferritic/Martensitic Steel P92." Key Engineering Materials 777 (August 2018): 356–60. http://dx.doi.org/10.4028/www.scientific.net/kem.777.356.

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Precipitate phases in the P92 F/M steel after normalization at 1323 K (1050 °C) for 30 min followed by air cooling to room temperature have been investigated by transmission electron microscopy (TEM). Three types of phases consisting of M3C, MX and M2C have been identified. Needle-like Fe-rich M3C carbide, (Fe0.87Cr0.13)3C, has a simple orthorhombic lattice, and a size of 7-18 nm in short axis and 73-190 nm in long axis. Sphere-shaped Nb-rich MC carbide with a f.c.c. crystal structure has a chemical formula of about (Nb0.69V0.15Fe0.1Mo0.06)C and a size of 12 to 88 nm in diameter. Large-sized Fe-rich M2C phase exhibits a block-like shape, and has a hexagonal crystal structure. TEM examination indicated that the number density of both the Fe-rich M3C carbide and Nb-rich MX phase is higher than Fe-rich M2C carbide phase.

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Nagaoka, Toru, Hiroyuki Watanabe, Masao Fukusumi, Yusuke Kitamura, Tadashi Mizuno, Genryu Abe, Yoshiaki Morisada, and Hidetoshi Fujii. "Microstructural Evaluation of Friction Stir Processed D2 Tool Steel." Materials Science Forum 735 (December 2012): 422–26. http://dx.doi.org/10.4028/www.scientific.net/msf.735.422.

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Modification of AISI D2 tool steel was conducted by friction stir processing (FSP). Effects of tool rotational speed on microstructural evolution and mechanical properties were investigated. Though coarse primary carbides in the size of 10-50 m were observed before FSP, fine carbides smaller than 20 m and martensitic matrix with fine grains were obtained after FSP. High hardness of over 900 HV, higher than the hardness in conventional D2 tool steel, was achieved under the condition of moderate rotational speed.

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Dudova, Nadezhda, Roman Mishnev, and Rustam Kaibyshev. "The Microstructural Criterion for Creep Strength Breakdown in a 10%Cr Martensitic Steel." Materials Science Forum 879 (November 2016): 465–70. http://dx.doi.org/10.4028/www.scientific.net/msf.879.465.

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A 10%Cr martensitic steel with 3%Co and 0.008%B tempered at 770°C exhibits no creep strength breakdown at a temperature of 650°C up to an extremely high rupture time of ∼4×104 h under an applied stress of 120 MPa. The minimum creep rate was ∼3×10-11 s-1. Microstructural characterization showed that superior creep resistance associated with a high stability of tempered martensite lath structure. Boundary M23(B⋅C)6 phase particles are highly stable against coarsening under long-term aging and creep conditions. These particles retain their orientation relationship with ferritic matrix unchanged under creep at a temperature of 650°C. As a result, no migration of lath boundaries and their transformation to subboundaries diminishing the long-range elastic stress fields take place. The role of M(C,N) carbonitrides in achieving extraordinary high creep strength consists in hindering the knitting reaction between mobile lattice dislocations and lath boundaries.

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Hanamura, Toshihiro, Shiro Torizuka, Soutaro Tamura, Shohei Enokida, and Hiroshi Takech. "Effect of Austenite Grain Size on the Mechanical Properties in Air-Cooled 0.1C-5Mn Martensitic Steel." Materials Science Forum 783-786 (May 2014): 1027–32. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.1027.

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In 0.1C-5Mn steels, 5%Mn addition increases hardening ability and makes 100% martensitic transformation even in air cooling without water quenching. Their Ms and Mf temperatures are in the range of 350-250°C, and subzero treatment is not needed. This makes it possible to measure Ms and Mf temperatures accurately by dilatometry. Utilizing a newly developed experimental technique that makes it possible to examine phase transformation behavior and conduct tensile testing with the same specimen, we examined these relationships with identical specimens and obtained the following results. Ms temperature decreases as much as 40 K with a decrease in austenite grain size from 254 to 30 m. Regarding martensite structure, the packet size and the block length decrease, while the lath width does not change, with the refinement of austenite grain size by about one tenth. True stress - true strain curves obtained up to fracture elucidates that the austenite refinement substantially improves true fracture strength and greatly increases true fracture strain of martensite, potentially invalidating the conventional concept of a trade-off balance between strength and ductility.

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Mohd Tahir, Suraya, Nosrati Shohreh, Mohamed Ariff Azmah Hanim, and Mansor Hashim. "Thermal Stability of CK60 Steel Nano-Crystallized By Drilling Method." Applied Mechanics and Materials 564 (June 2014): 461–66. http://dx.doi.org/10.4028/www.scientific.net/amm.564.461.

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In present study drilling as a new Surface Sever Plastic Deformation technique (SSPD) has been applied to commercial CK60 steel plate to create a nanoCrystalline (NC) structured layer.The CK60 steel plate with tempered martensitic crystalline structure has been drilledusing hard titanium coated drilling bit under 20 m/min cutting speed. The formed surface nanocrystalline (NC) layers characterized by using field emission scanning electron microscope (FESEM) and microhardness tests. The results showed that the hardness of formed NC layer with almost 50nm grain sizes was more than twice of the martensitic base metal hardness. The thermal stability of NC layer has been studied in the range of 673 to 923K and the results showed that created fine grain structurehad higher thermal stabilitycompared to CK60 steel samples with coarse granular crystalline structure. The microhardness of NC layers reduced from 9.8 to 9.1 GPa after 1 hour tempering at923K.

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Tioguem, Frank, Matthieu Maziere, Franck Tankoua, André Galtier, and Anne-Françoise Gourgues-Lorenzon. "Identification of ductile to brittle transition temperature by using plane strain specimen in tensile test and correlation with instrumented Charpy impact test: experimental and numerical study." Mechanics & Industry 19, no. 1 (2018): 107. http://dx.doi.org/10.1051/meca/2017034.

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This study addresses the correlation between the ductile-to-brittle transition temperature ranges of high strength 4140 steel obtained respectively from tensile tests under plane strain (PS) conditions and from conventional Charpy impact tests. Specimens were taken respectively at 25 mm (P) and at 55 mm (M) from skin of a cylindrical 90-mm-radius hot rolled bar water quenched from 875 °C, tempered at 600 °C and air cooled. P and M samples respectively showed a fully martensitic and a martensite-bainite microstructure. Fracture surface observations showed good agreement for physical fracture mechanisms (cleavage facet size, mixed ductile + brittle fracture in the transition region, ductile fracture at higher temperatures) between PS and Charpy, in particular sensitivity of upper bainite to cleavage fracture that reduces fracture energy in the lower self-energy on Charpy tests.

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Johnson, E., A. Johansen, L. Sarholt-Kristensen, E. Gerritsen, J. Politiek, H. A. A. Keetels, and W. M. J. Coene. "XTEM microscopy of martensitic transformations in noble gas implanted stainless steel." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 4 (August 1990): 206–7. http://dx.doi.org/10.1017/s0424820100174163.

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Cross-sectional transmission electron microscopy (XTEM) has been used to study the microstructure of noble gas implanted austenitic stainless steels, and in particular to analyse the depth distribution of implantation induced martensite in relation to the general radiation damage distribution.Large discs of low-austenitic stainless steels have been ion implanted with noble gases to fluences in the range l.1020 - 1.1021 m-2. Samples of the implanted discs for cross-sectional transmission electron microscopy (XTEM) were made by electroplating the implanted surface with a 3 mm thick layer of nickel, cutting 3 mm discs from the interface and electropolishing the discs to perforation using a Struers TENUPOL immersion jet apparatus.In samples implanted with low fluences (1-1020 m-2) the implantation zone consists of a heavily damaged top layer containing a dense distribution of microscopic noble gas inclusions, which are visible in defocusing phase contrast. The inclusions are ∽ 3-5 nm in diameter, and the smallest inclusions contain noble gas in the solid phase.

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Shimizu, Kazumichi, Takeshi Naruse, Yaer Xinba, Hideki Teramachi, Shinji Araya, and Masahide Ishida. "High Temperature Erosion Behaviors of High V-Cr-Ni Spheroidal Carbides Cast Iron." Key Engineering Materials 457 (December 2010): 255–60. http://dx.doi.org/10.4028/www.scientific.net/kem.457.255.

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High temperature erosion occurs in production of the inorganic fibrous insulator in plant. Austenitic and martensitic stainless steels are often used for these severe high temperature erosion conditions. The paper presents erosion properties of some stainless steels, several cast iron and cast steel using a blast type high temperature erosion furnace. The solid particle erosion behavior at high temperatures (900°C) of carbon steel of S50C, carbon tool steel of SK3, SUS403, SUS630, and High V-Cr-Ni spheroidal carbides cast iron (SCI-VCrNi) are investigated. Alumina balls entrained in a stream of hot air impact on the target materials at an air velocity of 100 m/s. the impingement angle is 90°. The influence of the test temperature and the material removal are discussed. The high temperature erosion behaviors of specimens are discussed by the eroded surface morphology and vertical section observation using SEM and optical microscopy observations.

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Hu, Wenfeng, Hongmei Zhu, Jipeng Hu, Baichun Li, and Changjun Qiu. "Influence of Vanadium Microalloying on Microstructure and Property of Laser-Cladded Martensitic Stainless Steel Coating." Materials 13, no. 4 (February 12, 2020): 826. http://dx.doi.org/10.3390/ma13040826.

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Martensitic stainless steel (MSS) coatings with different vanadium (V) contents (0–1.0 wt%) by microalloying have been successfully fabricated utilizing a unique laser cladding technique. The microstructure and properties of the resulting MSS coatings, with and without element V addition, have been carefully investigated by various advanced techniques, including XRD, SEM, TEM, microhardness tester, universal material testing machine, and electrochemical workstation. It was found that the V-free coating was mainly composed of martensite (M) and ferrite (F), trace M23C6 and M2N, while the V-bearing coatings consisted of M, F, M23C6, and VN nano-precipitates, and their number density increased with the increase of V content. The V microalloying can produce a significant impact on the mechanical properties of the resulting MSS laser-cladded specimens. As the V content increased, the elongation of the specimen increased, while the tensile strength and microhardness increased firstly and then decreased. Specifically, the striking comprehensive performance can be optimized by microalloying 0.5 wt% V in the MSS coating, with microhardness, tensile strength, yield strength, and elongation of 500.1 HV, 1756 MPa, 1375 MPa, and 11.9%, respectively. However, the corrosion resistance of the specimens decreased successively with increasing V content. The microstructure mechanisms accounting for the property changes have been discussed in detail.

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Selokar, Ashish, Ravi Kant, D. B. Goel, and U. Prakash. "Solid Particle Erosion Behaviour of Martensitic and Nitrogen Alloyed Austenitic Stainless Steel." Advanced Materials Research 1043 (October 2014): 45–49. http://dx.doi.org/10.4028/www.scientific.net/amr.1043.45.

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In the present work, comparison of solid particle erosive behaviour of 13/4 steel and Nitrogen alloyed austenitic stainless steel (23/8N steel) have been studied using air jet erosion testing. Air jet erosion testing has been performed at various angles for as received samples at 31 m/s velocity and a discharge rate of 3 gm per minute by alumina particles with angular shape and 53-63μm size. Microstructure, eroded surface characteristics, mechanical properties and erosion rate are characterized by using scanning electron microscope, hardness and tensile testing. 23/8N steel shows good hardness coupled with high tensile toughness and work hardening ability, which leads to improved erosion resistance. The surface morphology analysis of the worn out surfaces, cumulative weight loss measurements and steady state of erosion rate results were used to understand the effect of nitrogen on the degradation mechanisms. The results show that 23/8N steel exhibits excellent resistance to erosion in comparison to13/4 steel.

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Fedorova, Irina, Zhanna Yanushkevich, Andrey Belyakov, and Rustam Kaibyshev. "Microstructure and Deformation Behavior of a Hot Forged 9%Cr Creep Resistant Steel." Advanced Materials Research 409 (November 2011): 672–77. http://dx.doi.org/10.4028/www.scientific.net/amr.409.672.

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The tempered microstructure and the creep behaviour were studied in an ultra low carbon 9%Cr martensitic creep resistant steel. The starting material was forged at 1050°C followed by air cooling and then tempered at a temperature of 750°C for 3 hours. This treatment resulted in the mean transverse lath size of about 240 nm; the dislocation density in lath interiors comprised 4 × 1014 m-2. The tempered martensite lath structure (TMLS) is characterised by homogeneous precipitation of numerous MX-type carbonitrides and a small amount of relatively coarse M23C6–type carbides. Three kinds of MX carbonitrides were observed in the tempered lath martensite structure. Those were plate-shaped particles with longitudinal size of about 15 nm and thickness of 3 nm; round-shaped particles of about 10 nm in diameter; and relatively large almost equiaxed particles with mean size of about 90 nm. The large MX particles were resulted from incomplete dissolution of such carbonitrides at 1050°C, while the nanoscale particles homogeneously precipitated during the tempering. The creep tests conducted at 650°C showed that the studied steel demonstrated superior creep resistance. Namely, the rupture time was about an order as long as that for P92-type creep resistant steel.

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Rogozhkin, S., A. Nikitin, N. Orlov, A. Bogachev, O. Korchuganova, A. Aleev, A. Zaluzhnyi, et al. "Evolution of microstructure in advanced ferritic-martensitic steels under irradiation: the origin of low temperature radiation embrittlement." MRS Advances 2, no. 21-22 (December 27, 2016): 1143–55. http://dx.doi.org/10.1557/adv.2016.657.

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ABSTRACTAdvanced reduced activation ferritic/martensitic steels and oxide dispersion-strengthened steels exhibit significant radiation embrittlement under low temperature neutron irradiation. In this study we focused on atom probe tomography (APT) of Eurofer97 and ODS Eurofer steels irradiated with neutrons and heavy ions at low temperatures. Previous TEM studies revealed dislocation loops in the neutron-irradiated f\m steels. At the same time, our APT showed early stages of solid solution decomposition. High density (1024 m–3) of ∼3–5 nm clusters enriched in chromium, manganese, and silicon atoms were found in Eurofer 97 irradiated in BOR-60 reactor to 32 dpa at 332°C. In this steel irradiated with Fe ions up to the dose of 24 dpa, pair correlation functions calculated using APT data showed the presence of Cr-enriched pre-phases.APT study of ODS Eurofer found a significant change in the nanocluster composition after neutron irradiation to 32 dpa at 330 °C and an increase in cluster number density. APT of ODS steels irradiated with Fe ions at low temperatures revealed similar changes in nanoclusters.These results suggest that irradiation-induced nucleation and evolution of very small precipitates may be the origin of low temperature radiation embrittlement of f\m steels.

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Szczucka-Lasota, Bożena, Tomasz Węgrzyn, Tadeusz Szymczak, and Adam Jurek. "High Martensitic Steel after Welding with Micro-Jet Cooling in Microstructural and Mechanical Investigations." Materials 14, no. 4 (February 16, 2021): 936. http://dx.doi.org/10.3390/ma14040936.

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Modern means of transport will play a significant role in the smart city. In the automotive industry, high-strength steels such as Docol are employed more often. This kind of material is relatively not very well weldable. The main reason is related to the Heat Affect Zone, the region in which cracks occur. Another disadvantage is connected with differences in values of ultimate strength of parent and weld material. The differences can be diminished using the correct welding process, which employs nickel and molybdenum electrode wires at much lower sulfur content. The weld metal deposit contains mainly martensite and bainite with coarse ferrite, while the parent material contains mainly martensite and rather fine ferrite. New technology, micro-jet cooling after the joining process enables to obtain the microstructure of weld metal deposit at acceptable parameters. Welding with micro-jet cooling could be treated as a very promising welding Docol steels process with high industrial application. Results of non-destructive inspections on macro samples corresponded with further destructive test results (tensile strength, hardness, fatigue, metallographic structure analyses). This article aims to verify fatigue behavior of Docol 1200 M steel after welding supported by the cooling using the micro-jet technique. For the first time, micro-jet cooling was used to weld this kind of steel to check the mechanical properties of the joint, especially to determine the fatigue limit. This study is formulated as follows: investigating fatigue resistance of the Docol 1200 M weld manufactured at the cooling process with micro-jets. The joints were produced in the MAG (Metal Active Gas) technology modified by micro-jet cooling. The results collected in the fatigue test were processed in the form of the Wöhler’s S–N diagram following the fatigue limit of the weld examined. All data have indicated the possibility of obtaining a new method of welded joints with high fatigue limit minimum of 480 MPa. It could be important to achieve a tensile strength of 700 MPa while maintaining the best relative elongation at the level of the base material.

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Hojo, Tomohiko, Junya Kobayashi, Koh-ichi Sugimoto, Akihiko Nagasaka, and Eiji Akiyama. "Effects of Alloying Elements Addition on Delayed Fracture Properties of Ultra High-Strength TRIP-Aided Martensitic Steels." Metals 10, no. 1 (December 19, 2019): 6. http://dx.doi.org/10.3390/met10010006.

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To develop ultra high-strength cold stamping steels for automobile frame parts, the effects of alloying elements on hydrogen embrittlement properties of ultra high-strength low alloy transformation induced plasticity (TRIP)-aided steels with a martensite matrix (TM steels) were investigated using the four-point bending test and conventional strain rate tensile test (CSRT). Hydrogen embrittlement properties of the TM steels were improved by the alloying addition. Particularly, 1.0 mass% chromium added TM steel indicated excellent hydrogen embrittlement resistance. This effect was attributed to (1) the decrease in the diffusible hydrogen concentration at the uniform and fine prior austenite grain and packet, block, and lath boundaries; (2) the suppression of hydrogen trapping at martensite matrix/cementite interfaces owing to the suppression of precipitation of cementite at the coarse martensite lath matrix; and (3) the suppression of the hydrogen diffusion to the crack initiation sites owing to the high stability of retained austenite because of the existence of retained austenite in a large amount of the martensite–austenite constituent (M–A) phase in the TM steels containing 1.0 mass% chromium.

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Ye, Tie, Ping Yang, Zhi Wen Lu, and Chun Hua Ma. "Research of Deformation Law on High Manganese Steel with Different Alloy Composition." Key Engineering Materials 727 (January 2017): 9–16. http://dx.doi.org/10.4028/www.scientific.net/kem.727.9.

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The organizations and phase composition after forging and heat treatment of the stacking fault energy for the three high manganese steel with 2.99 mJ/m2,7.9 mJ/m2and23 mJ/m2 were observed. It’s analysised that the microstructure and orientation change of three high manganese steel by SEM and EBSD and the effect of alloy elements and the composition of the material on microstructure of high manganese steel; Through Static compressive deformation of cylindrical specimen under different strain rates experimental, the effect of strain rate on the deformation mechanism of different components of high manganese steel was analysised. Cylindrical specimens by static compression at different strain rates, analysis of strain rate on the different components of high manganese steel impact deformation mechanism; The mechanical performance characteristics are analyzed under different strain rate of three components high-manganese steel by stress - strain curves. By Compressive Split-Hopkinson Pressure Bar experiments to study the mechanism of high manganese steel deformation at high strain rates. The study found: the exclusion of the impact of the martensitic transformation can produce 18Mn high manganese TRIP or TWIP effect after deformation. Through observation and calculation, it found C, Al's content of alloying elements on the grain sizes less affected, but the starting temperature of martensitic transformation and layer greatly affects high manganese wrong size possible. Through analysis, found C, Al decides that the high content of alloying elements manganese organization original phase composition and deformation mechanism; organizations γ + ε-M + α'-M high manganese TRIP effect occurs, organizations γ + ε-M's high manganese TRIP effect occurs, tissue TWIP effect of high manganese steel γ.

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Tokarev, Aleksandr, Zinaida Bataeva, Gennadii Grachev, Aleksandr Smirnov, Maksim Khomyakov, and Artiom Gerber. "Laser-Plasma Treatment of Structural Steel." Applied Mechanics and Materials 788 (August 2015): 58–62. http://dx.doi.org/10.4028/www.scientific.net/amm.788.58.

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To conduct high production hardening modification of iron-carbon and titanium alloy surface layers a laser-plasma method (LPM) is developed. The method is based on the use of optical pulse discharge plasma. A discharge is ignited with laser pulses repeated with a high frequency by a CO2-laser oscillator - amplifier system. A laser pulse is focused on the treated surface. To form plasma in alignment with the beam in the laser head, a high velocity gas flow (air, nitrogen, argon, and carbon dioxide) is created. The pressure of the plasma-forming gas can reach 0.5 MPa, and the output speed of the laser head can be 300 m/s.The results of the experiment on the impact of laser-plasma action on the structure and microhardness of the structural steel surface are presented. Laser-plasma treatment leads to the formation of a layer with the martensitic structure on the surface of structural low-alloyed steel 40Kh. This layer is formed due to quenching in a liquid state (QLS) and quenching in a solid state (QSS). The microhardness of the martensitic layer is 11-13 GPa, the hardened zone depth reaches 0.3 mm. It is proposed to use laser-plasma treatment of structural steel as a method for the local surface hardening of machine parts and tools.

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He, Yan Lin, Na Qiong Zhu, Wei Sen Zheng, Xiao Gang Lu, and Lin Li. "Thermodynamic and Kinetic Calculation of Non-Equilibrium Microstructure Design of TRIP Steel." Materials Science Forum 783-786 (May 2014): 766–70. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.766.

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The non-equilibrium microstructure of Fe-C-Mn-Si TRIP steel is designed bythermodynamic and kinetic calculation. The upper limit of bainitic transformation temperature iscalculated and compared to that characterized by CCT curve determination. s M temperature isdetermined based on thermodynamics of martensitic transformation and sublattice model. Thecalculation is conducted via TQ6-patch in Thermo-Calc software. Comparison between thecalculations and experiments reveals the relationship between non-equilibrium phase compositionand heat treatment parameters which can be utilized to achieve the elaborate design of alloy and heattreatment for super TRIP steel.

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30

Hanna, Farah, Guilhem Michel Roux, Olivier Asserin, Jean Christophe Brachet, and René Billardon. "Tempering Kinetics of the X10CrMoVNb9-1Martensitic Steel." Solid State Phenomena 172-174 (June 2011): 845–50. http://dx.doi.org/10.4028/www.scientific.net/ssp.172-174.845.

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This work is part of a collaborative study between CEA-Saclay and LMT-Cachan on the numerical simulation of multi-pass GTA-Welding of thick specimens made of X10CrMoVNb9-1 (ASTM 387 or “T91”) steel. The final objective of this paper is to exhibit the prediction capabilities of an improved version of the Thermo-Metallurgical-Mechanical "TMM" model for X10CrMoVNb9-1 martensitic steel (initially developed by G.-M. Roux). In this paper, focus is made on the modelling of the martensite tempering due to the complex thermal loadings induced by the multi-pass process. Herein, it has been chosen to study the tempering kinetics via the evolution of the free carbon content or, conversely, the carbides precipitation overall fraction, growth and dissolution. Thermo-Electric Power (TEP) measurements as well as hardening measurements have been used to investigate the tempering phenomenon. Measurements are fast to perform and are not very sensitive to the geometry of the material (in opposite to resistivity measurements). A phenomenological tempering model was developed and identified from several tests at constant tempering temperatures ranging from 550°C up to 750°C. The improved TMM model including this tempering model was used to perform the 2D finite element analysis of the 16-pass GTA welding process of a narrow groove butt-weld. The predictions are favourably compared with the “real” microstructure.

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Zhang, Guangming, Kun Mo, Yinbin Miao, Xiang Liu, Jonathan Almer, Zhangjian Zhou, and James F. Stubbins. "Load partitioning between ferrite/martensite and dispersed nanoparticles of a 9Cr ferritic/martensitic (F/M) ODS steel at high temperatures." Materials Science and Engineering: A 637 (June 2015): 75–81. http://dx.doi.org/10.1016/j.msea.2015.04.037.

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32

Wang, Jiamei, and Le Fu Zhang. "Effects of cold deformation on electrochemical corrosion behaviors of 304 stainless steel." Anti-Corrosion Methods and Materials 64, no. 2 (March 6, 2017): 252–62. http://dx.doi.org/10.1108/acmm-12-2015-1620.

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Purpose The purpose of this study was to investigate the effects of deformation-induced martensite on electrochemical corrosion behaviors of 304 austenitic stainless steel in a simulated primary water environment of a pressurized water reactor nuclear power plant with boric acid and lithium hydroxide contaminated with chloride by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Mott–Schotty curves and X-ray photoelectron spectroscopy (XPS). Design/methodology/approach The effects of deformation-induced martensite transformation on electrochemical corrosion behaviors of 304 austenitic stainless steel was investigated in a simulated primary water environment of a pressurized water reactor nuclear power plant with boric acid and lithium hydroxide contaminated with 0.1 M Cl− by potentiodynamic polarization, EIS, Mott–Schotty curves and XPS in this paper. Findings The results revealed that the martensitic phase contents increased with the level of cold deformation. The general corrosion current density and the corrosion potential increased and decreased, respectively, with the increase of cold deformation degree. However, the pitting potential decreased as the cold deformation increased up to 20 per cent, then a slight increase was observed at 35 per cent cold working. It was found from Mott–Schottky curves and XPS analysis that as the cold deformation degree increased from 0 to 35 per cent, the doping concentrations of the oxide films increased; however, the film thickness decreased, which indicates that both density and integrity of the films are degraded significantly as the deformation degree increases, and this ultimately contributes to the significant increment of the general corrosion rate and reduction of the pitting corrosion resistance. Originality/value The effects of deformation-induced martensite transformation on electrochemical corrosion behaviors of 304 austenitic stainless steel was investigated in a simulated primary water environment of a pressurized water reactor nuclear power plant with boric acid and lithium hydroxide contaminated with 0.1 M Cl− by potentiodynamic polarization, EIS, Mott–Schotty curves and XPS in this paper.

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33

Sahu, P. "Bainite and stress-induced martensite in an AISI type 300 steel: an X-ray diffraction study of the microstructure by the Rietveld method." Journal of Applied Crystallography 38, no. 1 (January 19, 2005): 112–20. http://dx.doi.org/10.1107/s0021889804028717.

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The present study concerns the X-ray characterization of the microstructure of an AISI type 300 stainless steel with composition Fe–17Cr–8Ni–1Mn–0.1C (wt%), undergoing stress-induced martensite and bainite transformations following γ(f.c.c.) → α(b.c.c.) transformation reactions. The methodology applied is a Rietveld whole X-ray profile fitting technique, adopting the recently developed softwareMAUD(Materials Analysis Using Diffraction) which incorporates the Popa model for crystallite size and microstrain [root mean square (r.m.s.) strain] and the preferred orientation of the crystallites. The analysis also considers the lattice-defect-related features of the evolved microstructures, namely stacking-fault probabilities and dislocation-density values. The study revealed a high degree of stress-induced martensitic transformation (∼94%) in the cold-worked (hand-filed powder) state of the material. However, no low-temperature martensitic transformation could be observed in this class of materials at temperatures below the martensite start temperature (Ms). On isothermal aging at 673 K for different periods of time (1, 3 and 6 h), the austenite transforms partially into bainite with continuously varying volume fractions (17, 42 and 44%) and the corresponding microhardness values are 218, 230 and 233 kg mm−2. The size–strain–shape analysis adopting the Popa model reveals anisotropic and almost isotropic values of the crystallite sizes and r.m.s. strains in the austenite and bainite microstructures, respectively. High values of the dislocation density (∼1016 m−2) were observed in the bainite due to the plastic deformation of the austenite induced by the shape change of the growing bainite. The values of all the above defect parameters have been evaluated and compared in order to elucidate the structure–property relationships.

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Lee, Yoon-Seok, Yuta Kondo, and Mitsuhiro Okayasu. "Friction-Induced Martensitic Transformation and Wear Properties of Stainless Steel under Dry and Wet Conditions." Metals 10, no. 6 (June 3, 2020): 743. http://dx.doi.org/10.3390/met10060743.

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The wear characteristics of SUS304 and SUS316 stainless steels were evaluated at the rotation speeds of 100 m/s, 200 m/s, and 300 m/s under dry and wet conditions. The transition of friction-induced martensite occurred in wear-affected regions of two materials, regardless of the wear test conditions. The specific wear rates (Ws) of both stainless steels increase with increasing rotation speeds, regardless of the circumstances. Moreover, Ws of SUS304 and SUS316, obtained under dry conditions, is significantly higher than that of SUS304 and SUS316 obtained under wet conditions, respectively. This is because that the water film on the wet ring can act as a liquid lubricant between the ring and the block during the tests. After the wear tests, the hardness changes of both SUS304 and SUS316 are much higher under dry conditions, compared to those under wet conditions.

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35

Li, Yanhui, Tongtong Xu, Shuzhong Wang, Balazs Fekete, Jie Yang, Jianqiao Yang, Jie Qiu, et al. "Modelling and Analysis of the Corrosion Characteristics of Ferritic-Martensitic Steels in Supercritical Water." Materials 12, no. 3 (January 28, 2019): 409. http://dx.doi.org/10.3390/ma12030409.

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The dependencies of weight gain of 9-12 Cr ferritic-martensitic steels in supercritical water on each of seven principal independent variables (temperature, oxygen concentration, flow rate, exposure time, and key chemical composition and surface condition of steels) have been predicted using a supervised artificial neural network (ANN). The relative significance of each independent variable was uncovered by fuzzy curve analysis, which ranks temperature and exposure time as the most important. The optimized ANN, not only satisfactorily represents the experimentally-known non-linear relationships between the corrosion characteristics of F-M steels and the key independent variables (demonstrating the effectiveness of this technique), but also predicts and reveals that the effects of oxygen concentration on the weight gains, to a certain degree, is influenced by the flow rate and temperature. Finally, according to the ANN predicted-results, departure of oxidation kinetics from the parabolic law, and basic cause of chromium content in steel substrate influencing the corrosion rate, and the synergetic effects of dissolved oxygen concentration, flow rate, and temperature, are discussed and analyzed.

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36

TOLULOPE LOTO., ROLAND, and BRYAN UCHE AYOZIE. "Electrochemical Analysis of the Anti-corrosion Properties of Benzonitrile Compound on Quenched 420 Martensitic Steel in Strong Aqueous Environment." Oriental Journal of Chemistry 34, no. 4 (August 16, 2018): 1749–54. http://dx.doi.org/10.13005/ojc/340406.

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Investigation of the corrosion inhibition properties of benzonitrile compound on the surface degradation of quenched 420 martensitic steel in 6 M H2SO4 was evaluated through the application of potentiodynamic polarization method, micro analytical study and ATR-FTIR spectroscopic analysis. Experimental data showed optimal inhibition performance of the compound with peak inhibition efficiency of 99.4% with mixed type inhibition but dominant anodic inhibition properties. The inhibiting compound significantly influenced the thermodynamic behaviour of the steel resulting in chemisorption adsorption mechanism onto steel surface in consonance with Langmuir and Freundlich adsorption models with correlation coefficients of 1 and 0.7570. The transmittance of identified functional groups of benzonitrile from ATR-FTIR spectroscopy decreased at extended wavelengths due to surface coverage and adsorption of the compound onto the steel.

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37

Zhang, Weiping, Liping Guo, Zhenyu Shen, Jingping Xin, Qunying Huang, Yaxia Wei, Yunxiang Long, Xiong Zhou, and Cheng Chen. "Evolution of Dislocation Loops Induced by Different Hydrogen Irradiation Conditions in Reduced-Activation Martensitic Steel." Materials 11, no. 11 (November 14, 2018): 2276. http://dx.doi.org/10.3390/ma11112276.

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Hydrogen can be induced in various ways into reduced-activation ferritic/martensitic (RAFM) steels when they are used as structural materials for advanced nuclear systems. However, because of the fast diffusion of hydrogen in metals, the effect of hydrogen on the evolution of irradiation-induced defects was almost neglected. In the present work, the effect of hydrogen on the evolution of dislocation loops was investigated using a transmission electron microscope. Specimens of reduced-activation ferritic/martensitic (RAFM) steels were irradiated with hydrogen ions to 5 × 1020 H+ • m−2 at 523–823 K, and to 1 × 1020 H+ • m−2 − 5 × 1020 H+ • m−2 at 723 K. The experimental results reveal that there is an optimum temperature for dislocation loop growth, which is ~723 K, and it is greater than the reported values for neutron irradiations. Surprisingly, the sizes of the loops produced by hydrogen ions, namely, 93 nm and 286 nm for the mean and maximum value, respectively, at the peak dose of 0.16 dpa under 723 K, are much larger than that produced by neutrons and heavy ions at the same damage level and temperature. The results indicate that hydrogen could enhance the growth of loops. Moreover, 47.3% 1 2 a0 <111> and 52.7% a0 <100> loops were observed at 523 K, but 1 2 a0 <111> loops disappeared and only a0 <100> loops existed above 623 K. Compared with the neutron and ion irradiations, the presence of hydrogen promoted the formation of a0 <100> loops.

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38

Kipelova, Alla, Rustam Kaibyshev, Andrey Belyakov, Izabella Schenkova, and Vladimir Skorobogatykh. "Microstructure Evolution in a 3%Co Modified P911 Heat Resistant Steel under Creep Conditions." Advanced Materials Research 89-91 (January 2010): 295–300. http://dx.doi.org/10.4028/www.scientific.net/amr.89-91.295.

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The microstructural changes in a 3%Co modified P911 heat resistant steel were examined under static annealing and creep at elevated temperatures. The quenched steel was tempered at temperatures ranging from 673 to 1073 K for 3 hours. The temperature dependence of hardness for the tempered samples exhibits the maximum at 723 – 823 K which is associated with the precipitations of fine carbides with an average size of about 20 nm. The transverse lath size of martensitic structure is  200 nm after air quenching and remains unchanged under tempering at temperatures below 800 K. An increase in tempering temperature to 1073 K resulted in hardness drop. Coagulation of carbides and growth of martensitic laths takes place at these temperatures. The creep tests were carried out at 873 and 923 K up to rupture, which occurred after about 4.5 × 103 hours. The structural changes in crept specimens were characterized by the development of coarse laths/subgrains. The mean transverse size of which was  0.67 and  1.3 m after the creep tests at 873 and 923 K, respectively. On the other hand, an average size of second phase particles of  165 nm was observed in the samples tested at both temperatures.

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Le, Nhung Thi, Khanh Mai Pham, Hai Minh Le, and Nam Duong Nguyen. "THE RELATIONSHIP BETWEEN CONTINUOUS COOLING RATE AND MICROSTRUCTURE IN THE HEAT AFFECTED ZONE (HAZ) OF THE DISSIMILAR WELD BETWEEN CARBON STEEL AND AUSTENITIC STAINLESS STEEL." Acta Metallurgica Slovaca 23, no. 4 (December 4, 2017): 363. http://dx.doi.org/10.12776/ams.v23i4.1002.

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This paper investigates the changed in the microstructure in HAZ of dissimilar weld between carbon steel and 304 austenitic stainless steel. Continuous cooling transformation diagrams (CCT), peak temperature profiles and cooling rates can be used to predict the change in the microstructure of the HAZ during the welding process. Optical microscopy, X – ray, SEM and TEM were used to determine the phases which formed in HAZ of carbon steel and austenitic stainless steel. The results of this study indicate that grain size in HAZ depended on the temperature at that point could be reached during the welding. Fully Martensitic layer observed at the interface in carbon side due to the combination of the rapid cooling subsequent to weld and local chemical composition. Cooling rate played the rule on forming Widmanstatten ferrite, Bainite and Pearlite. On the other hand, microstructures and grain size in HAZ of austenitic stainless steel were not affected by temperature and cooling rate. Carbides precipitation (M23C6, M7C3), however, were found in the boundary of grains.

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40

Soares, Renata B., Wagner R. C. Campos, Pedro L. Gastelois, Waldemar A. A. Macedo, Luís F. P. Dick, and Vanessa F. C. Lins. "Electrochemical Properties of Passive Film Formed on Supermartensitic Stainless Steel in a Chloride Medium." Corrosion 76, no. 9 (June 10, 2020): 884–90. http://dx.doi.org/10.5006/3230.

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The electrochemical behavior and the electronic properties of passive films formed on a super martensitic stainless steel (SMSS) used in oil and gas industries were investigated in aqueous 0.6 M and 2.1 M NaCl solutions with additions of sodium acetate and acetic acid (pH 4.5). Open-circuit potential transients, electrochemical impedance spectroscopy, cyclic voltammetry, and x-ray photoelectron spectroscopy were measured to characterize the passive film formed on SMSS. The electrochemical behavior of the steel in an aqueous solution of 0.6 M NaCl presented the highest pitting potential and the highest polarization resistance in relation to the NaCl/NaAc solution. The passive film of SMSS in an aqueous solution of NaCl presented a thickness of 18.40 nm, three times the thickness of the oxide film in NaCl/NaAc, and consisted of FeO, Cr2O3, MoO2, and spinels such as FeCr2O4 species that are a p-type semiconductor, but may also contain a small fraction of the Fe2O3 and MoO3 oxides. Additionally, it was shown that the passive layer after immersion in a saline solution also contains hydroxides such as FeOOH and Cr(OH)3.

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41

PROCHENKA, Paweł, and Jacek JANISZEWSKI. "Assessment and Comparison of the Mechanical Properties of Laser Welded Joints in Docol 1200M and Strenx S700MC Steel Alloy Grades Under Impact Loads." Problems of Mechatronics Armament Aviation Safety Engineering 11, no. 1 (March 31, 2020): 17–30. http://dx.doi.org/10.5604/01.3001.0014.0282.

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The article evaluates the strength and ductility of laser butt joints made of 2 mm Docol 1200 M martensitic steel sheets based on the hardness, quasi-static and dynamic tensile tests. Technological research of laser welding process was carried out on welding cell using IPG fiber – based welding source with 6 kW maximum power. The tests were carried out for parallel and perpendicular orientation of specimens by rolling direction. In addition, the obtained results were compared with the analogous results obtained during the Strenx S700 MC steel tests. Dynamic tests were performed using the tensile split Hopkinson pressure bar technique with strain rates of 103 s-1. The obtained results showed that the strength of Docol 1200 M under dynamic tensile test conditions are similar to the material strength under static tensile test conditions. However, due to the breaking of the specimens in the heat affected zone, the strength of the welded joint is much lower than in base material, which was not observed during the Strenx S700 MC steel tests.

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42

Kim, Sung Ho, Chang Hee Han, and Woo Seog Ryu. "Formation of Nano M₂X Particles by a Tempering in High Cr Ferritic/Martensitic Steel." Solid State Phenomena 135 (February 2008): 107–10. http://dx.doi.org/10.4028/www.scientific.net/ssp.135.107.

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The precipitation of nano Cr2N particles in high Cr FM steels has been studied. The nitrogen content of the FM steels was changed to form stable Cr2N particles. Tempering temperature was also changed from 500 oC to 800 oC to study the precipitation behavior of the Cr2N particles with the tempering temperature. The Cr2N particles remained as a stable phase at a higher tempering temperature by increasing the nitrogen content. The shape of these particle was a fine needle type which was very similar to V(C,N) particles. The size of some Cr2N particles was increased as the nitrogen content increased. But these precipitates were not dissolved or largely coarsened during a creep deformation at 600°C. So it seems that they may act as an effective obstacle against a dislocation glide during a creep deformation, thus contribute to an increase of the creep rupture strength in high Cr FM steels.

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43

Hanna, Farah, Guilhem Michel Roux, Olivier Asserin, Jean Christophe Brachet, and René Billardon. "Modelling of the Non-Isothermal Austenite Formation Kinetics of a X10CrMoVNb9-1 Martensitic Steel." Solid State Phenomena 172-174 (June 2011): 815–20. http://dx.doi.org/10.4028/www.scientific.net/ssp.172-174.815.

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This work is part of a collaborative study between CEA-Saclay and LMT-Cachan on the numerical simulation of multi-pass GTA-Welding of thick specimens made of X10CrMoVNb9-1 (ASTM 387 or “T91”) steel. This material is considered as a candidate for some components of future Very High Temperature nuclear Reactors. Some parts of these components should be manufactured by assembling thick components (typically 200 mm) using narrow groove multi-pass GTA-Welding process. This welding process generates complex thermo-mechanical cycles in the HAZ (Heat Affected Zone) inducing complex microstructural transformations and residual stresses which should affect the integrity of the vessels behaviour. In a previous study, G.-M. Roux [1] developed a first version of a Thermo-Metallurgical-Mechanical "TMM" model for the X10CrMoVNb9-1 martensitic steel. This model was validated regarding residual stresses on simple mono-pass spot-welding tests. In this paper, focus is made on the modelling of the complex austenitisation process of the tempered martensitic steel as induced by the multi-pass process. Three different approaches are presented, viz. a model first proposed by Brachet et al., second a new model based on JMA approach and last, the simple differential Leblond model that is implemented in various finite element codes. These models are identified from standard dilatometry tests performed over a large range of heating rates, viz. [0.1°C/s, 100°C/s]. Finally, the response of these models, and therefore, their predicting capabilities, are compared to the experimental response of the material for different transients that have been designed to be representative of the temperature history in different points of a multi-pass welding HAZ.

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Gokce, Harun. "Optimisation of Cutting Tool and Cutting Parameters in Face Milling of Custom 450 through the Taguchi Method." Advances in Materials Science and Engineering 2019 (September 19, 2019): 1–10. http://dx.doi.org/10.1155/2019/5868132.

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Stainless steels with unique corrosion resistance are used in applications with a wide range of fields, especially in the medical, food, and chemical sectors, to maritime and nuclear power plants. The low heat conduction coefficient and the high mechanical properties make the workability of stainless steel materials difficult and cause these materials to be in the class of hard-to-process materials. In this study, suitable cutting tools and cutting parameters were determined by the Taguchi method taking surface roughness and cutting tool wear into milling of Custom 450 martensitic stainless steel. Four different carbide cutting tools, with 40, 80, 120, and 160 m/min cutting speeds and 0.05, 0.1, 0.15, and 0.2 mm/rev feed rates, were selected as cutting parameters for the experiments. Surface roughness values and cutting tool wear amount were determined as a result of the empirical studies. ANOVA was performed to determine the significance levels of the cutting parameters on the measured values. According to ANOVA, while the most effective cutting parameter on surface roughness was the feed rate (% 50.38), the cutting speed (% 81.15) for tool wear was calculated.

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Alvarado-Meza, M. A., E. García-Sanchez, O. Covarrubias-Alvarado, A. Salinas-Rodriguez, M. P. Guerrero-Mata, and R. Colás. "Effect of the High-Temperature Deformation on the M s Temperature in a Low C Martensitic Stainless Steel." Journal of Materials Engineering and Performance 22, no. 2 (May 31, 2012): 345–50. http://dx.doi.org/10.1007/s11665-012-0258-4.

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Bobir, S. V., I. Yu Prikhodko, D. V. Loshkarev, S. S. Zakharchuk, and P. V. Krot. "Analysis of the amount of retained austenite in the structure of steel rolls for sheet rolling." Fundamental and applied problems of ferrous metallurgy, no. 34 (2020): 256–64. http://dx.doi.org/10.52150/2522-9117-2020-34-256-264.

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The amount of residual austenite in martensitic roll steels is an important technological parameter of heat treatment, which affects the performance properties of the rolls. But determining its amount in roll steels is a complex and not fully solved scientific and technical problem. The aim of the work was to comparatively analyze the amount of residual austenite in the structure of alloy steel rolls by X-ray diffraction, ultrasonic methods and metallography analysis. However, the qualitative difference of microstructures in the content of the light phase - austenite, confirms the results of X-ray diffraction analysis. No correlation was found between the austenite content in the samples and their hardness. It was found that the X-ray method, based on the comparison of the intensities of the α- and γ-phase lines of iron, overestimates the value of the amount of residual austenite in some samples of roll steels. The results of the analysis of residual austenite by ultrasound rate showed better convergence. The amounts of residual austenite, calculated on the sample of stainless steel (100% γ-Fe), had reduced values (2.6-4.5%). The most accurate results on the amount of residual austenite gave the use of the established regression dependence with the selected standard (2.7-7.8%). This dependence is obtained at the speed of sound in austenite ~ 4000 m / s. It is determined that the application of the ultrasonic method allows to determine the content of residual austenite in the samples of roll steels quite quickly and accurately.

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Thamizhmanii, S., Rosli Ahmad, and S. Hasan. "Performance of CBN and PCBN Tools on the Machining of Hard AISI 440C Martensitic Stainless Steel." Advanced Materials Research 264-265 (June 2011): 1137–47. http://dx.doi.org/10.4028/www.scientific.net/amr.264-265.1137.

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In this study, flank wear on CBN and PCBN tools due to cutting forces were studied. Turning tests were carried using cutting speeds of 100, 125, 150, 175 and 200 m/min with feed rates of 0.10, 0.20 and 0.30 mm/rev and constant depth of cut. The performances of tools were evaluated based on the flank wear and cutting forces. There is clear relationship between flank wear and cutting forces while turning hard martensitic stainless steel by CBN and PCBN tools. Low cutting forces leads to low flank wear formation and low cutting forces provided good dimensional accuracy of the work material including low surface roughness. Flank wear formation was mostly caused by abrasion and adhesion. The built up edges formed reduced the cutting forces and also causes the heat generated at tool tip and work interface. High cutting forces are identified and this may be due to heat and flank wear combinations. Flank and crater wear on the rake face and hard metal deposition due to diffusion of metals on the cutting tool surface are the damages occurred during process.

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YOSHIZAWA, Mitsuru, Masaaki IGARASHI, and Taiji NISHIZAWA. "Effect of Tungsten on the Ostwald Ripening of M₂₃C₆ Carbides in Martensitic Heat Resistant Steel." Tetsu-to-Hagane 91, no. 2 (2005): 272–77. http://dx.doi.org/10.2355/tetsutohagane1955.91.2_272.

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Ye, Zhongfei, Pei Wang, Dianzhong Li, and Yiyi Li. "M 23 C 6 precipitates induced inhomogeneous distribution of silicon in the oxide formed on a high-silicon ferritic/martensitic steel." Scripta Materialia 97 (March 2015): 45–48. http://dx.doi.org/10.1016/j.scriptamat.2014.10.028.

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Fuchs-Godec, R. "The Erosion−Corrosion Inhibition of AISI 431 Martensitic Stainless Steel in 2.0 M H2SO4Solution UsingN-Alkyl Quaternary Ammonium Salts as Inhibitors." Industrial & Engineering Chemistry Research 49, no. 14 (July 21, 2010): 6407–15. http://dx.doi.org/10.1021/ie100275a.

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Journal articles on the topic 'Martensitic (M) steel'

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