Journal articles: 'Ferrite-pearlite'

1

Hasegawa, Hiroshi, Tatsuya Nakagaito, and Yoshimasa Funakawa. "Effect of the Austenite Interface on Pearlite Transformation Behavior." Materials Science Forum 941 (December 2018): 639–44. http://dx.doi.org/10.4028/www.scientific.net/msf.941.639.

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The effect of the characteristics of austenite interface with ferrite on the pearlite transformation behaviour after intercritical annealing was investigated. Most austenite grains were situated mainly on ferrite grain boundaries and had the Kurdjumv-Sachs (K-S) or near K-S relationship to one of the neighbor ferrite grains before pearlite transformation. The pearlite transformation started mainly from the austenite grain boundary faced to ferrite. The pearlite transformation showed stasis. This indicates that some austenite is stabilized thermally against the pearlite transformation. The fraction of austenite having only the K-S or near K-S interface to neighbor ferrite grains was correspond to the fraction of austenite grains which does not include pearlite. The pearlite transformation was difficult to start from austenite interface having the K-S relationship to ferrite since the interface between austenite grains and ferrite grains was stabilized energetically in the case of their interface having the K-S relationship.

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2

Yilmaz, Aytac, Can Ozkan, Jilt Sietsma, and Yaiza Gonzalez-Garcia. "Properties of Passive Films Formed on Ferrite-Martensite and Ferrite-Pearlite Steel Microstructures." Metals 11, no. 4 (April 6, 2021): 594. http://dx.doi.org/10.3390/met11040594.

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The effect of ferrite-pearlite and ferrite-martensite phase combinations on the passive layer properties of low carbon steel is investigated in a 0.1 M NaOH solution. Heat treatments were designed to obtain ferrite-pearlite and ferrite-martensite microstructures with similar ferrite volume fractions. Potentiostatic polarisation and electrochemical impedance spectroscopy (EIS) results demonstrated the lower barrier properties of passive films on ferrite-martensite microstructure compared to the ones formed on ferrite-pearlite microstructure. This was attributed to the higher donor density of the passive layer on ferrite-martensite samples, measured with Mott–Schottky analysis. This behaviour was explained by the complex microstructure morphology of the martensite phase that led to the formation of a more defective passive film.

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Xue, Fei, Zhi Feng Luo, Wei Wei Yu, Zhao Xi Wang, and Lu Zhang. "Study on Banded Structure in Low Carbon Vessel Plate for Nuclear Power Plant." Applied Mechanics and Materials 44-47 (December 2010): 1763–66. http://dx.doi.org/10.4028/www.scientific.net/amm.44-47.1763.

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In this paper, the role of the pearlite-banded structure on fatigue crack growth behavior was investigated on carbon vessel plate material SA516, which is commonly used in the nuclear power plants. Along pearlite-banded orientation, in situ fatigue tests indicate that the crack initiated and propagated in the ferrite and then extended along the ferrite-pearlite interface when it met pearlitic colony. For comparison, the cyclic loading was also carried out perpendicular to the banding direction of the microstructure, and an intense crack branching was observed which led to fatigue crack retardation. Besides, the orientation perpendicular to banded pearlite in the investigated ferrite-pearlite steel was found to have a lower fatigue crack growth rate.

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Furuhara, Tadashi, Tomokazu Moritani, K. Sakamoto, and Tadashi Maki. "Substructure and Crystallography of Degenerate Pearlite in an Fe-C Binary Alloy." Materials Science Forum 539-543 (March 2007): 4832–37. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.4832.

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Microstructures formed by degenerate pearlite transformation in an Fe-0.38mass%C alloy were studied by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Degenerate pearlite which contains fine cementite particles even at the growth front was observed with other structures such as proeutectoid ferrite, lamellar pearlite and bainite in a temperature range between 773K and 923K. As the isothermal transformation temperature is lowered, a fraction of the degenerate pearlite increases. The degenerate pearlite consists of ‘block’ (a region in which ferrite orientations are nearly the same) and ‘colony’ (a region containing cementite particles of nearly the same orientation), both of which are similar to those in lamellar pearlite. Block boundaries within an austenite grain are generally of high-angle type and their misorientations deviate largely from intervariant relationships for the K-S orientation relationship. In contrast, colony boundaries are of low-angle type. Cementite films are formed along those ferrite boundaries in the degenerate pearlite, presumably formed by encounter of the blocks or colonies.

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Zhou, D. S., and G. J. Shiflet. "Ferrite: Cementite crystallography in pearlite." Metallurgical Transactions A 23, no. 4 (April 1992): 1259–69. http://dx.doi.org/10.1007/bf02665057.

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6

Sivaraman, V., S. Sankaran, and L. Vijayaraghavan. "Effect of cutting parameters on cutting force and surface roughness during machining microalloyed steel: Comparison between ferrite–pearlite, tempered martensite and ferrite–bainite–martensite microstructures." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 232, no. 1 (March 7, 2016): 141–50. http://dx.doi.org/10.1177/0954405416635479.

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Three different microstructures, namely ferrite–pearlite, tempered martensite and ferrite–bainite–martensite of 38MnSiVS5 microalloyed steel, were produced using controlled thermomechanical processing. The properties are comparable to quenched and tempered steel. The developed microstructures were turned to evaluate their machinability. Mixed modes of response were observed while ferrite–bainite–martensite microstructure exhibits better machinability by way of good surface texture/finish, the ferrite–pearlite microstructure of least strength encounters smaller cutting force.

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7

Wang, Yu Hui, Ya Nan Zheng, Tian Sheng Wang, Bo Liao, and Li Gang Liu. "Phase Transformation Behaviors of Nb-V-Ti Microalloyed Pipeline Steel X70." Advanced Materials Research 750-752 (August 2013): 380–84. http://dx.doi.org/10.4028/www.scientific.net/amr.750-752.380.

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The CCT (continuous cooling transformation) diagrams of the Nb-V-Ti without Mo containing microalloyed pipeline steel X70 were investigated. The microstructures observed in continuous cooled specimens are composed of P (pearlite), PF (polygonal ferrite), QF (quasi-polygonal ferrite), and GF (granular bainite ferrite). At low cooling rates between 0.1°C/s and 1°C/s, the microstructure of the steel consisted of banded ferrite and pearlite but higher cooling rates suppressed its formation.

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8

Mrvar, Primož, Mitja Petrič, and Jožef Medved. "Influence of Cooling Rate and Alloying Elements on Kinetics of Eutectoid Transformation in Spheroidal Graphite Cast Iron." Key Engineering Materials 457 (December 2010): 163–68. http://dx.doi.org/10.4028/www.scientific.net/kem.457.163.

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Paper deals with influence of cooling rate and alloying elements on kinetics of eutectoid transformation in spheroidal graphite cast iron (SGI). Transformation of austenite can proceed into ferrite and graphite (FeFeG) and/or in pearlite (Fe  FeFe3C). Examination of eutectoid transformation was made by evaluating the “in-situ” dilatation curves together with metallographic examinations, DTA, and dilatation analyses in solid state. ThermoCalc software was applied for thermodynamic calculations of phase equilibria. Based on numerous quantitative relations, such as relation between fractions of ferrite and pearlite in the as-cast SGI that was determined by analysis of dilatometric curves and taking into account also composition of melt, ferrite/pearlite ratio in the microstructure could be determined in a very short time. Thus the melt composition could be corrected by adding Cu and/or Mn or Si, respectively, using the "in situ" dilatation analyses. Characteristic temperatures of eutectoid transformation have been established from the kinetics of austenite transformation and from temperature dependence of ferrite and/or pearlite growth. Kinetics curves that enable to determine fractions of single microstructure constituents in the microstructure as function of transformation time, mainly used for ferrite and pearlite SGI, can be well determined with physical sigmoidal Boltzmann model.

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9

Lopes, Maximiano Maicon Batista, and André Barros Cota. "A study of isochronal austenitization kinetics in a low carbon steel." Rem: Revista Escola de Minas 67, no. 1 (March 2014): 61–66. http://dx.doi.org/10.1590/s0370-44672014000100009.

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The austenite formation under isochronal conditions in Nb microalloyed low carbon steel was studied by means of dilatometric analysis and the data was adjusted to the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation, for different heating rates and for three initial microstructures. It was shown that the kinetics of austenitization of a pearlite+ferrite structure is faster than that of martensite (tempered martensite) at a heating rate of 0.1ºC/s. For heating rates higher than 0.1ºC/s, the kinetics of austenitization of a martensite structure is faster than of pearlite+ferrite one. The K parameter of the JMAK equation increases with the heating rate for the three previous microstructures and it is greater for the initial microstructure composed of ferrite+pearlite. At lower heating rates, the formation of austenite in this steel is controlled by carbon diffusion, independently of the initial microstructure. At higher heating rates, the formation of austenite from an initial microstructure composed of pearlite and ferrite is controlled by interface-controlled transformation.

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10

Liu, Man, Guang Xu, Guanghui Chen, and Zhoutou Wang. "Study on the transformation and microstructure evolution during hot-charging rolling process of a weathering steel." Metallurgical Research & Technology 117, no. 3 (2020): 304. http://dx.doi.org/10.1051/metal/2020027.

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The effect of hot-charging temperature (HCT) on the transformation and microstructure evolution of a weathering steel was investigated by metallography and dilatometry. The results show that the microstructure consisted of ferrite and pearlite in all specimens when the HCT was between 500 ∼ 850 °C. The difference was that pearlite amount increased obviously at 750 °C, which is detrimental to the plasticity of steels. The reason for more pearlite is that ferrite and austenite coexisted at 750 °C, which belongs to the dual-phase region temperature. The reversed transformation of ferrite to austenite happened and the pre-existing austenite became coarse during the secondary austenization. The carbon content in fine reversed austenite was relatively low, while the coarse austenite contained higher carbon content, which decomposed into blocky pearlite in the final cooling process. Therefore, to obtain the desirable ferrite phase, the HCT of about 750 °C should be avoided. The results provide theoretical reference for optimizing hot-charging rolling process parameters.

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11

Zhen, Cai, Xin Ping Mao, Si Qian Bao, and Zhao Gang. "Study on Deformation-Induced Pearlite Transformation in Vanadium Microalloyed Eutectoid Steel." Advanced Materials Research 1156 (December 2019): 17–24. http://dx.doi.org/10.4028/www.scientific.net/amr.1156.17.

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In this paper, the hot compression tests were performed to study on deformation-induced pearlite transformation in vanadium microalloyed eutectoid steel. The results showed that volume fraction of deformation -induced pearlite were higher and the pearlite were spheroidized better under lower strain rate and higher strain in vanadium microalloyed steel. Ferrite grains and granular cementites were further refined through vanadium microalloying combined with deformation-induced pearlite transformation .Vanadium dissolved in γmatrix could retard deformation-induced pearlite transformation under low strain, vanadium carbides precipitated due to strain-induced precipitation eliminate the retardation when the strain was increased to a certain extent. Under heavy deformation, ferrite grains and granular cementites in vanadium microalloyed steel were finer compared with vanadium free steel.

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12

Mrvar, Primož, Milan Tribžan, Jožef Medved, and Alojz Križman. "Study of the Eutectoid Transformation in the As-Cast Spheroidal Graphite Cast Iron with 'in Situ' Dilatation Analysis – Method for Quality Control." Materials Science Forum 508 (March 2006): 287–94. http://dx.doi.org/10.4028/www.scientific.net/msf.508.287.

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The eutectoid transformation of the spheroidal graphite cast iron (S.G.I.) has been investigated with “in situ” dilatometer, which was made for the investigation of the cast iron alloys. The investigation of the eutectoid transformation has been taking place by evaluation of the “insitu” dilatation curves in connection with metallographic examinations, chemical analyses and thermodynamic calculations of the phase equilibriums. By dilatometric curves it is possible to follow the exact eutectoid transformation of austenite. On a basis of numerous quantitative relations, as the relation between the ferrite and pearlite fractions in the as-cast SGI, which was determined by the analysis of the dilatometric curves and the composition, the ratio between ferrite and pearlite in the microstructure could be determined in a very short time. From the kinetics of austenite transformation and temperature dependence of the ferrite or pearlite growth the following characteristic temperatures of the eutectoid transformation have been established: the ferrite nucleation o Tα , the beginning of the ferrite growth Tα , and pearlite growth Tp , respectively. Kinetic curves, which show the fraction of the single microstructure constituents in the microstructure in dependence of the transformation time for mainly ferrite SGI, are good represented by the physical sigmoidal Boltzmann model.

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13

Li, Li Zhang, He Wei, Lin Lin Liao, Yin Li Chen, Hai Feng Yan, Guang Hua Liu, and Zhi Wei Sun. "Continuous Cooling Phase Transformation Rule of 20CrMnTi Low-Carbon Alloy Steel." Materials Science Forum 944 (January 2019): 303–12. http://dx.doi.org/10.4028/www.scientific.net/msf.944.303.

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Gear steel is a ferritic steel. In the rolling process, the ideal structure is ferrite + pearlite, and bainite or martensite is not expected. However, due to the high alloy content, the hardenability is good, and the bainite or martensite structure is very likely to be generated upon cooling after rolling. In this paper, phase transformation rules during continuous cooling of 20CrMnTi with and without deformation were studied to guide the avoidance of the appearance of bainite or martensite in steel. A combined method of dilatometry and metallography was adopted in the experiments, and the dilatometer DIL805A and thermo-simulation Gleeble3500 were used. Both dynamic and static continuous cooling transformation (CCT) diagrams were drawn by using the software Origin. The causes of those changes in starting temperature, finishing temperature, starting time and transformation duration in ferrite-pearlite phase transformation were analyzed, and the change in Vickers hardness of samples with different cooling rate was discussed. The results indicate that with different cooling rate, there are three phase transformation zones: ferrite-pearlite, bainite and martensite. Deformation of austenite accelerates the occurrence of transformation obviously and moves CCT curve to left and up direction. When the cooling rate is lower than 1 °C/s, the phases in samples are mainly ferrite and pearlite, which is the ideal microstructure of experimental steel. As the cooling rate increases, starting temperature of ferrite transformation in steel decreases, starting time reduces, transformation duration gradually decreases, and the Vickers hardness of samples increases. Under the cooling rate of 0.5 °C/s, ferrite transformation in deformed sample starts at 751.67 °C, ferrite-pearlite phase transformation lasts 167.9 s, and Vickers hardness of sample is 183.4 HV.

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14

Bataev, Ivan A., Igor A. Balagansky, Anatoly Bataev, and Kazuyuki Hokamoto. "Transformation of Structure in Carbon Steel Specimen under Loading by Mach Stem, Formed in Preliminary Compressed High Explosive Charge TG-40." Materials Science Forum 673 (January 2011): 89–94. http://dx.doi.org/10.4028/www.scientific.net/msf.673.89.

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A structure of a carbon steel specimen after explosive loading is investigated. The loading was executed by Mach stem, formed in high explosive charge that was preliminary compressed by advanced wave in ceramic bar. In the original condition the specimen had a typical for low carbon steel ferrite-pearlite structure. Metallographic analysis has shown that during the process of the explosive loading the following structural changes took place: formation of numerous deformation twins in both ferrite grains and pearlite colonies (i.e. in two-phase structure); formation of extended bands of localized deformation, which are not crystallographically connected with the original ferrite-pearlite structure; fine grains formation in zones of severe plastic flow. The size of the ferrite grains is by an order of magnitude less than the original grains size. According to the authors’ opinion, above-noted structural peculiarities demonstrate that loading conditions achieved in the current loading scheme differ from common. The phenomenon of non-typical twinning in heterogeneous structure (pearlite) indirectly evidences that extremely high stresses and strain rates took place in the specimen during the loading.

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15

Zhou, Xiao Ling, Ke Han, Zhong Ming Ren, and Zeng Li. "Magnetic Field-Induced Granular Pearlite at Early Stages of Phase Transformation." Advanced Materials Research 650 (January 2013): 178–84. http://dx.doi.org/10.4028/www.scientific.net/amr.650.178.

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ffects of high magnetic fields (HMF) up to 19.81T on pearlite phase transformation are studied by examination of the microstructures of a Fe-0.47C-2.3Si-3.2Mn (wt %) alloy partially isothermally processed above the eutectoid temperature. The results show that granular pearlite (GP) can be obtained at earlier transformation stages. The evolution of the granular pearlite is always accompanied by the formation of lamellar pearlite. TEM analysis reveals the existence of sub-grain boundaries within GP colonies and indicates that the nucleation of ferrite matrix in GP belongs to multiple nucleation mechanism. Most of carbides at the early stage of pearlite formation are found to precipitate at the α/γ interface--the growing front of ferrite phases, and some of coarse carbides can further develop into thin lamellar cementite.

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16

Al-Abbasi, F. M. "Micromechanical modeling of ferrite-pearlite steels." Materials Science and Engineering: A 527, no. 26 (October 2010): 6904–16. http://dx.doi.org/10.1016/j.msea.2010.07.045.

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Bhadeshia, Harshad K. D. H. "Alternatives to the Ferrite-Pearlite Microstructures." Materials Science Forum 284-286 (June 1998): 39–50. http://dx.doi.org/10.4028/www.scientific.net/msf.284-286.39.

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Wang, Ya Nan, Li Ying Han, and Ying Sun. "Effect of Normalizing Pre-Treatment on Microstructure of Laser Hardened Ductile Iron." Advanced Materials Research 189-193 (February 2011): 1146–50. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.1146.

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We adjusted the pearlite content of ductile iron matrixin by normalizing, finding that the microstructures of laser hardened ductile iron with different pearlite content and distribution were quite different. According to their microstructure characteristics, there are three types: ⑴pearlite transformation type; ⑵ pearlite and ferrite transformation type; ⑶ferrite transformation type. We also studied the microhardness of different ductile iron laser hardened layers and the phase around the graphite ball. The results showed that under the appropriate laser treatment process (laser output power of 1kw, spot diameter of 5.2mm, scan speed of 16mm / s), ledeburite shell, with the hardness up to HV0.11070, formed around the graphite ball in the surface layer of ductile iron hardened layer. Outside the ledeburite was the carbon diffusion zone with hardness of HV0.1850. It was composed by the plate martensite of large needle and large amount of residual austenite. In the hardened layer of ferrite transformation type, martensite formed out around the ledeburite shell or graphite ball.

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Khan, Adnan Raza, and Sheng Fu Yu. "Microstructure and Mechanical Properties of 3-Wire Electroslag Welded (ESW) High-Speed Pearlitic Rail Steel Joint." Key Engineering Materials 837 (April 2020): 28–34. http://dx.doi.org/10.4028/www.scientific.net/kem.837.28.

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The present paper aims at utilizing the 3-wire electroslag welding (ESW) to join high-speed pearlitic rail steels where microstructure and mechanical properties were investigated. The welded joint has produced an improved fracture force of 1396KN. WM was consisted of ferrite and pearlite having hardness of 27HRC, tensile strength of 748MPa and toughness of 12J, successively. HAZ was composed of pro-eutectoid ferrite and pearlite, where austenite grain size and pearlite colony size were reduced by moving away from the fusion line. In HAZ, near to the fusion line, the austenite grain size was 143±19μm, pearlite colony size was 52±9μm and pearlite interlamellar spacing was 90±27nm, which has produced hardness of 43.5HRC, tensile strength of 1228MPa, and toughness of 8J, successively. The entire investigation concludes that 3-wire ESW is an optimum and viable method, which has provided fine pearlite microstructure along with improved hardness and tensile strength.

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20

Triguero, Patricia Romano, Enno Zinngrebe, and Stefan Melzer. "Orientation Relationships of Coarse Pearlite Islands Formed in Tundish Well Clogging Deposits." Materials Science Forum 702-703 (December 2011): 814–17. http://dx.doi.org/10.4028/www.scientific.net/msf.702-703.814.

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It is well known that clogging constitutes one of the main issues encountered during casting in the steel industry. To clarify how clogging deposits are formed and to minimize their impact in the process, their microstructure and relationship between the different constituents need to be studied. In the tundish well the studied deposits consist predominantly of Al2O3 inclusion fans but are found interspersed with islands of pearlite along the margins. These islands of coarse pearlite, i.e. thick cementite/ferrite plates surrounded by large ferrite grains are formed even in Ti-rich ultra low carbon steels and the orientation relationships are used to track the initial composition of the deposit when it was formed. The crystallographic orientation relationship (ORS) between ferrite and cementite in pearlite can follow Isaichev (I), Bagaryatskii (B) or Pitsch-Petch (PP). Results showed that the pearlite islands are formed with ORS relatively close to PP and are intersected by alumina particles which show a specific relation with the islands and with the ferrite matrix. It was concluded that an external carbon source and temperatures just above the eutectoid are needed to form those islands.

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21

Duan, Zheng Tao, Yan Mei Li, Fu Xian Zhu, and Hui Yun Zhang. "Continues Cooling Transformation Behavior of Low Carbon Mn-Nb-B Steel." Advanced Materials Research 335-336 (September 2011): 595–98. http://dx.doi.org/10.4028/www.scientific.net/amr.335-336.595.

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The continues cooling transformation (CCT) of a low carbon Mn-Nb-B steel in the undeformed and deformed conditions were investigated, respectively. The CCT diagrams of the steel were constructed. The microstructures and microhardness were analysized. The results showed that the microsructures contains ferrite, pearlite, granular bainite, acicular ferrite and lath bainite depending on cooling rate; Deformation moved the CCT curve to the top left corner, increased the transformation start temperatures slightly, and promoted the formation of ferrite and pearlite. Furthmore deformation also fined the transformed microstructures.

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22

Bisong, Mbelle Samuel, Kisito Pierre, and Valeriy Lepov. "THERMAL INFLUENCE ON THE MICROSTRUCTURE AND THE MICRO HARDNESS OF A CARBON STEEL WELD PROBES." International Journal of Engineering Technologies and Management Research 5, no. 8 (March 21, 2020): 1–10. http://dx.doi.org/10.29121/ijetmr.v5.i8.2018.275.

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During welding, the heat produced during the process can affect the microhardness and the microstructure of the material. The change in the microstructure and the microhardness can be discovered by carrying out a microhardness test on the welded sample and compare changes in the three different zones i.e the base, the weld and the Heat affected zone or by carrying out a micro structural examination on the welded sample and see the grain dispersion in relation to their sizes. In this work, weld quality of manual arc welded samples of low-carbon steel St3spdestined for bridge construction to be used in Cameroon has been investigated. After a chemical analysis of the material, a micro hardness test and a micro structural examination was also done. Results show that a composition of pearlite and ferrite was seen with the print of the id enter of the micro hardness test. The formation of pearlite and ferrite in base metalis composed of 20/80 respectively. For weld zone and HAZ it changes due to thermal processes. So the microstructure analysis shows that the base metal is a ferrite and pearlite having a grain size of 11-12 on a scale corresponding to an average grain diameter ≈ 7 microns. The structure of the weld metal is also made up of ferrite and pearlite with columnar crystals of cast metal. The HAZ is made up of Widmanstätten. The width of the HAZ zone is about 1,5 mm. In different areas of heat affected zone is observed fine-grained ferrite-pearlite structure with a high degree of dispersion.

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Singh, Balbir, and D. Rai. "Modeling of Microstructural Gradients in TMCP Bars to Produce Value Added Products." Materials Science Forum 539-543 (March 2007): 4143–48. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.4143.

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Thermomechanical controlled processing of concrete reinforcement bars, comprising quenching and autotempering, produces a microstructural gradient across the diameter - tempered martensite near to the surface, bainite and/or degenerated pearlite in the intermediate layers and pearlite-ferrite within the core. Since martensite is the strength controlling phase in steels, its fractional thickness in TMCP bars have beeen correlated to tensile properties. The developed empirical model, helped in revealing that upto a fractional rim of about 20%, volume fraction of ferrite-pearlite predominantly influenced the YS, UTS and % elongation, whereas at higher fractions, martensite found to control these properties.

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Wang, Hai Chuan, Zhi You Liao, Shi Jun Wang, Yun Zhou, Bao Guo Wu, and Yuan Chi Dong. "Effect on Inclusion and Microstructure of Ultra-Low S and Low P Steels with Vacuum Treatment." Advanced Materials Research 503-504 (April 2012): 654–57. http://dx.doi.org/10.4028/www.scientific.net/amr.503-504.654.

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The simultaneous desulphurization and dephosphorization of molten steel with CaO-based slag containing BaO for vacuum treatment, and inclusion in steel and microstructure of steel are carried out separately. These results show that desulfurization rate exceed 92% and dephosphorization rate exceed 50% , final [S] content and [P] content in molten steel are less than 0.0024% and 0.020% respectively for all heats, and the lowest final [S] content and [P] content are 0.0012% and 0.010% respectively, they satisfy the demand of ultra-low S steels and low P steels; Comparing a grade 1.5 of inclusion level of the compared sample without vacuum treatment, inclusion level of these treated samples with vacuum is all less than grade 1.0 and that is less than grade 0.5 for 78% of treated samples; And micro-structure of the compared sample is ferrite + pearlite in steel base, but micro-structure of these treated samples is all needle-like ferrite + pearlite + netted ferrite in steel base and netted ferrite + pearlite in local area. This kind of fiber structure which comes from netted ferrite + needle-like ferrite and grade 0.5 of inclusion level can make steel possess better mechanical properties.

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Wu, Hui Bin, Guo Li Liang, Y. H. Wen, and C. C. Yang. "In Situ Study of Fracture Process for B-Class Shipbuilding Steel." Materials Science Forum 704-705 (December 2011): 1310–15. http://dx.doi.org/10.4028/www.scientific.net/msf.704-705.1310.

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Crack initiation, propagation and microfracture processes of B-class shipbuilding steel have been investigated by using an in-situ tensile stage installed inside a scanning electron microscope chamber, meanwhile the secondary crack propagation at low temperature brittle fracture has also been studied. It is revealed that micro cracks always nucleated at the notch of specimens due to the stress concentration and then propagate along the interface of ferrite-pearlite. The plastic deformation of polygonal ferrite occurred in the loading process, the cracks propagated as “Z” morphology in the matrix. In the low temperature brittle fracture zone, the secondary crack propagated through the ferrite matrix in the manner of transgranular crack. When the secondary crack propagated to pearlite region, the intragranular crack and transgranular crack were observed in the pearlite region .

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26

Güler, M. "Magnetism and Microstructure Characterization of Phase Transitions in a Steel." Advances in Condensed Matter Physics 2014 (2014): 1–4. http://dx.doi.org/10.1155/2014/408607.

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We present phase transitions in a low carbon steel according to existing phases and their magnetism. Scanning electron microscope employed research to clarify and evaluate the microstructural details. Additionally, we utilized from Mössbauer spectroscopy for magnetic characteristics of different existed phases. Scanning electron microscope examinations showed that the pure state of the steel was fully in the ferrite phase with equiaxed grains. Moreover, subsequent heat treatments on the studied steel also ensured the first austenite and then pearlite phase formation. Mössbauer spectroscopy of these phases appeared as a paramagnetic single-line absorption peak for the austenite phase and ferromagnetic six-line spectra for both ferrite and pearlite phases. From Mössbauer data, we determined that the internal magnetic fields of ferrite and pearlite phases were as 32.2 Tesla and 31.3 Tesla, respectively.

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27

Matusiewicz, P., J. Augustyn-Nadzieja, A. Czarski, and T. Skowronek. "Kinetics of pearlite spheroidization." Archives of Metallurgy and Materials 62, no. 1 (March 1, 2017): 231–34. http://dx.doi.org/10.1515/amm-2017-0034.

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Abstract The pearlite spheroidization in Fe-0.76%C high purity steel was investigated. The samples of a coarse pearlite microstructure were isothermal annealed at 700, 680, 660, 640 and 620°C for various times, up to 800 hours. For quantitative description of the spheroidization process stereological parameter, SV (ferrite/cementite interface surface density) was used. The activation energy 104.8±11.4 kJ/mol was found for the spheroidization process. This value shows good agreement with the activation energy for iron and carbon diffusion along a ferrite/cementite interface, so the coupled interface diffusion is the rule-controlling process.

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Torkkeli, Janne, Tapio Saukkonen, and Hannu Hänninen. "Effect of pearlite on stress corrosion cracking of carbon steel in fuel-grade ethanol." Corrosion Reviews 36, no. 3 (June 27, 2018): 281–93. http://dx.doi.org/10.1515/corrrev-2017-0072.

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AbstractThe selective dissolution of ferrite phase from the pearlite was studied in fuel-grade ethanol (FGE) to understand how it affects the stress corrosion cracking (SCC) mechanism of carbon steel in FGE. It was shown that microgalvanic coupling occurs between ferrite and cementite phases of the pearlite, leading to localized corrosion, which affects the SCC mechanism. The intergranular SCC mechanism stops at the pearlite, and the selective dissolution promotes the transgranular SCC mechanism. Cathodic polarization curves were measured for pure iron and cementite exposed to various FGE conditions. According to the results, cementite phase is, in most cases, a more favorable cathode in FGE.

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Radović, Nenad, Ankica Koprivica, Dragomir Glišić, Abdunnaser Fadel, and Djordje Drobnjak. "Influence of V and N on Transformation Behavior and Mechanical Properties of Medium Carbon Forging Steels." Materials Science Forum 638-642 (January 2010): 3459–64. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.3459.

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The influence of vanadium and nitrogen on microstructure and mechanical properties of medium-carbon steels has been studied by means of metallography and mechanical testing. Vanadium addition to the low nitrogen steel suppresses the formation of ferrite-pearlite following the low reheating temperatures and microstructure consists of bainitic sheaves. Increasing nitrogen at the same vanadium level promotes the acicular ferrite formation. For high reheating temperatures, dominantly acicular ferrite structure in both the low nitrogen and the high nitrogen vanadium steels is obtained. The results suggest that vanadium in solid solution promotes the formation of bainite, whereas the effect of nitrogen is related to the precipitation of VN particles in austenite with high potency for intragranular nucleation of acicular ferrite and to the precipitation of V(C,N) particles in ferrite with high potency for precipitation strengthening. Addition of both vanadium and nitrogen considerably increases the strength level, while CVN20 impact energy increases on changing the microstructure from bainitic ferrite to the fine ferrite-pearlite and acicular ferrite.

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Janakiram, S., J. Prakash Gautam, A. Miroux, J. Moerman, and Leo Kestens. "Microstructure and Texture Control in Cold Rolled High Strength Steels." Diffusion Foundations 22 (May 2019): 84–93. http://dx.doi.org/10.4028/www.scientific.net/df.22.84.

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Formability had been important property of metals which is attributed to the texture development during thermomechanical processing particularly during hot rolling and cold rolling. In the present paper, the high strength steels with different carbon and manganese composition have been hot rolled above and below of austenite recrystallization temperature and followed by fast cooling up to different coiling temperature to get hot bands with different texture and two phase microstructure consisting ferrite with pearlite, bainite and martensite. Subsequently, these hot bands were cold rolled with 80 percent under plain strain condition. The microstructure of cold rolled sheets samples were analyzed using scanning electron microscope and showed the cold rolled microstructure with strong pancaked of two phase which was carried from the hot rolling. Cold rolled texture in ferrite pearlite microstructure is completely replaced by new texture components from hot rolled condition without the effect of Tnr. Hot rolled texture was retained in ferrite-bainite and martensite microstructure with the effect of Tnr. Increase in alloy chemistry weakens the texture intensity in ferrite pearlite/bainite microstructure. Whereas increase in alloy chemistry strengthens the texture intensity in ferrite martensite microstructure.

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Zrník, Jozef, Sergey Dobatkin, and Libor Kraus. "Grain Refinement and Deformation Behaviour of Medium Carbon Steel Processed by ECAP." Key Engineering Materials 592-593 (November 2013): 307–12. http://dx.doi.org/10.4028/www.scientific.net/kem.592-593.307.

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The work presents the results on grains refinement of steel containing 0,45 wt pct carbon resulted from severe plastic deformation (SPD). Different steel structures from prior solutioning and/or thermomechanical treatment were prepared for deformation experimental. A coarse grain ferrite-pearlite structure was achieved applying solutioning. By application of thermomechanical (TM) controlled forging process, performing multistep open die forging, the refined ferrite-pearlite mixture was prepared. Final structure refinement of steel, having different initial structure, was then accomplished applying warm Equal Channel Angular Pressing (ECAP) at 400°C. Employment of this processing route resulted in extensive deformation of ferrite grains and cementite lamellae fragmentation. Applying the highest shear stress (εef- 4) the mixed structure of subgrains and ultrafine grains was present within the ferrite phase. In pearlite grains, modification of cementite lamellae due to shearing, bending, twisting and breaking was found efficient. The coarse cementite lamellae spheroidization was more efficient in prior TM treated steel. The tensile deformation records confirmed strength increase and diversity in strain hardening behaviour.

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Zrník, Jozef, Sergey Dobatkin, and George Raab. "Structure Refinement of Medium Carbon Steel and Deformation Properties Respond." Materials Science Forum 782 (April 2014): 104–10. http://dx.doi.org/10.4028/www.scientific.net/msf.782.104.

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The work presents the results on grains refinement of steel containing 0,45 wt pct carbon resulted from severe plastic deformation (SPD). Different steel structures from prior solutioning and/or thermomechanical treatment were prepared for deformation experimental. A coarse grain ferrite-pearlite structure was achieved applying solutioning. By application of thermomechanical (TM) controlled forging process, performing multistep open die forging, the refined ferrite-pearlite mixture was prepared. Final structure refinement of steel, having different initial structure, was then accomplished applying warm Equal Channel Angular Pressing (ECAP) at 400°C. Employment of this processing route resulted in extensive deformation of ferrite grains and cementite lamellae fragmentation. Applying the highest shear stress (εef - 4) the mixed structure of subgrains and ultrafine grains was present within the ferrite phase. In pearlite grains, modification of cementite lamellae due to shearing, bending, twisting and breaking was found efficient. The coarse cementite lamellae spheroidization was more efficient in prior TM treated steel. The tensile deformation records confirmed strength increase and diversity in strain hardening behaviour.

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33

Karkina, L. E., I. N. Karkin, I. G. Kabanova, and A. R. Kuznetsov. "Crystallographic analysis of slip transfer mechanisms across the ferrite/cementite interface in carbon steels with fine lamellar structure." Journal of Applied Crystallography 48, no. 1 (January 30, 2015): 97–106. http://dx.doi.org/10.1107/s1600576714026107.

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The results of crystallographic analysis of deformation transfer mechanisms across the ferrite/cementite interface in fine lamellar pearlite are presented. The possibility of a strain transfer was evaluated using the LRB criteria that are used for the slip transfer mechanisms across grain boundaries [Lee, Robertson & Birnbaum (1989).Scr. Metall.23, 799–803; (1990).Metall. Trans. A,21, 2437–2447; (1990).Philos. Mag. A,62, 131–153]. Dislocation reactions at the Fe/Fe3C interface were studied, taking into account Bagaryatsky and Isaichev orientation relationships between ferrite and cementite observed for fine lamellar pearlite. Slip planes and Burgers vectors of full and partial dislocations in cementite have been proposed on the basis of the results of atomistic simulations of stacking faults for some planes of cementite. It has been found that strain transfer through the Fe/Fe3C interface is possible only for half of the slip systems 1/2〈111〉{110}Fand for quarter of the slip systems 1/2〈111〉{112}Fof ferrite. Other slip systems do not cross the interface and are involved in the hardening of the ferrite phase of pearlite.

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Li, Xin, Jie Zhao, Xun Yang, Jun Cheng Bao, and Bao Qun Ning. "Effects of Cooling Rate on Microstructure and Properties of Nb-Ti Micro-Alloyed Steel." Applied Mechanics and Materials 341-342 (July 2013): 208–12. http://dx.doi.org/10.4028/www.scientific.net/amm.341-342.208.

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Continuous cooling transformation (CCT) curves of deformed austenite (A) of Nb-Ti microalloying high strength steel were measured using Gleeble-3800 thermo-mechanical simulator, and corresponding transformation and structure were analyzed, and the effects of cooling rate on the tested steels mechanical property were studied. The resultes showed that the Ar3transformation point decreased with increasing cooling rate after hot-rolling. The morphology of ferrite (F) grains changed from polygonal to lath, and the pearlite (P) colonies became more fine with increasing cooling rate. The quantity of ferrite and pearlite decreased, and the quantity of bainite (B) and martensite (M) increased. Then the hardness of Nb-Ti micro-alloyed steel is increased along with the increasing cooling rate, which may owing to the reasons that the hardness of ferrite and pearlite is far smaller than that of bainite and martensite, and the grain refinement causes the hardness increasing.

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Zhang, Shi Xin, Xiao Jun Deng, Shao Jun Liu, Ming Yan Wang, and Guo Qing Gou. "Research on SHCCT of Weather Resisting Plate for Vehicle." Applied Mechanics and Materials 423-426 (September 2013): 1955–62. http://dx.doi.org/10.4028/www.scientific.net/amm.423-426.1955.

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In order to help to design the bogies for vehicle, the morphology, microhardness and SHCCT diagram of SMA490BW high strength weather resisting plate was carried out. The morphology were ferrite and little pearlite and granular bainite of samples at different cooling speed. With the cooling rate increased, the t8/5 decreased but the hardness increased. The phase content was composed of pearlite, ferrite and bainite at lower cooling rate, but the phase content was totally composed of bainite.

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36

Hejazi, Daniel, Ahmed A. Saleh, Ayesha Haq, Druce Dunne, Andrzej Calka, Azdiar A. Gazder, and Elena V. Pereloma. "Role of Microstructure in Susceptibility to Hydrogen Embrittlement of X70 Microalloyed Steel." Materials Science Forum 783-786 (May 2014): 961–66. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.961.

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The effect of phases and steel processing on hydrogen uptake (diffusible and residual), surface and internal damage were evaluated using optical and scanning electron microscopy. The results have shown the fastest formation of blisters in ferrite-pearlite microstructure of strip, followed by equaixed ferrite-pearlite microstructure in normalised condition, then by ferrite-bainite microstructure. No blistering was observed in heat affected zone samples for up to 24 hrs charging. Analysis of hydrogen-induced cracking using electron back scattering diffraction has revealed that crack propagation has predominantly intragranular character without a clear preference on {001}, {110}, {112} and {123} planes and is independent of the steel microstructure and prior processing.

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37

Song, Zhuo Fei, Yun Li Feng, Run Ming Feng, and Shao Jiang Yin. "Research on Continuous Cooling Dynamic Transformation of T700." Advanced Materials Research 750-752 (August 2013): 416–19. http://dx.doi.org/10.4028/www.scientific.net/amr.750-752.416.

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Continuous cooling dynamic transformation regularity of T700 was investigated by gleeble-3500. The results show when the cooling rate is small organization is mainly composed of polygonal ferrite and pearlite and has minor banded organization. With the increase of cooling rate, begin to appear granular bainite. When cooling rate reaches 3/s or more, ferrite changes to quasi polygon, and start to appear small amount of bainite. when the cooling rate is 7°C/s, pearlite is disappeared in structure, granular bainite increases, quasipolygonal ferrite content is gradually decreased. When the cooling rate is increased to 10°C/s or above, organization is granular bainite.

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38

Zhao, F., C. L. Zhang, and Y. Z. Liu. "Ferrite Decarburization of High Silicon Spring Steel in Three Temperature Ranges." Archives of Metallurgy and Materials 61, no. 3 (September 1, 2016): 1715–22. http://dx.doi.org/10.1515/amm-2016-0252.

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Abstract Surface decarburization of high silicon spring steel in ambient air was studied. The experimental results confirmed the decarburized mechanism under AC1 temperature, in the temperature range of AC1-AC3 and AC3-G. Under AC1 temperature, pearlite spheroidization and surface decarburization are carried out simultaneously and pearlite spheroidization is reinforced. Considering the oxidation loss depth, the “true ferrite decarburized depth” at 850 °C (AC3-G) is still smaller than that at 760°C (AC1-AC3). That is because an “incubation period” must pass away before ferrite decarburization occurs in the temperature range of AC3-G, and the ferrite decarburized rate is limited to being equal to the partial decarburized rate.

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Tu, Xingyang, Yi Ren, Xianbo Shi, Changsheng Li, Wei Yan, Yiyin Shan, and Ke Yang. "Enhancing Strain Capacity by the Introduction of Pearlite in Bainite and Polygonal Ferrite Dual-Phase Pipeline Steel." Materials 14, no. 18 (September 17, 2021): 5358. http://dx.doi.org/10.3390/ma14185358.

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In this study the strain capacity and work-hardening behavior of bainite (B), bainite + polygonal ferrite (B + PF), and bainite + polygonal ferrite + pearlite (B + PF + P) microstructures are compared. The work hardening exponent (n), instantaneous work hardening value (ni), and differential Crussard-Jaoul (DC-J) analysis were used to analyze the deformation behavior. The best comprehensive mechanical properties were obtained by the introduction of the pearlite phase in B + PF dualphase with the tensile strength of 586 MPa and total elongation of 31.0%. The additional pearlite phase adjusted the strain distribution, which increased the initial work hardening exponent and then maintained the entire plastic deformation at a high level, thus delayed necking. The introduction of pearlite reduced the risk of micro-void initiation combined with the high frequency of high angle grain boundaries (HAGBs) in triple-phase steel, which led to a low crack propagation rate.

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HIRUKAWA, Hisashi, and Saburo MATSUOKA. "Nanoscopic Strength Analysis of Ferrite-Pearlite Steels." Transactions of the Japan Society of Mechanical Engineers Series A 68, no. 671 (2002): 1038–45. http://dx.doi.org/10.1299/kikaia.68.1038.

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41

Samuel, C., and S. Viswanathan. "Predicting Ferrite-Pearlite Ratios in Ductile Iron." International Journal of Metalcasting 4, no. 1 (January 2010): 72–74. http://dx.doi.org/10.1007/bf03355492.

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42

Purcino, E. C., and P. R. Cetlin. "Fracture mechanism of coarse pearlite/ferrite mixtures." Scripta Metallurgica et Materialia 25, no. 1 (January 1991): 167–70. http://dx.doi.org/10.1016/0956-716x(91)90374-a.

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43

Li, Zhengning, Fuan Wei, Peiqing La, Hongding Wang, and Yupeng Wei. "Enhancing Ductility of 1045 Nanoeutectic Steel Prepared by Aluminothermic Reaction through Annealing at 873 K." Advances in Materials Science and Engineering 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/5392073.

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The 1045 steel with lamellar spacing of pearlite in nanometer was prepared by aluminothermic reaction casting and annealed at 873 K (600°C) with different time. Microstructures of steels were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). Tensile properties of the steels were measured. The results showed that the lamellar spacing of the pearlite increased with the annealing time. It was found that the microstructure of steels consisted of nanocrystalline-ferrite matrix and laminar pearlite phase. The average grain sizes of the ferrite were 26.9, 27.0, 26.1, and 34.9 nm for the cast steel and samples annealed for 2, 4, and 6 h, respectively. As the annealing time increased, the volume fraction of the pearlite almost remained constant, while the laminar spacing of pearlite increased from 146 to 300 nm. The tensile and yield strength varied slightly; the elongation obviously improved. After annealing for 4 h, the elongation increased to be 33%, which was the reported highest value for the steel up to now and about twice of the conventional 1045 steel.

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Xin, Rui Shan, Hui Long An, Shuai Ren, Ji Tan Yao, and Jin Pan. "Behaviors of Continuous Cooling Transformation and Microstructure Evolution of a High Strength Weathering Prefabricated Building Steel." Solid State Phenomena 279 (August 2018): 21–25. http://dx.doi.org/10.4028/www.scientific.net/ssp.279.21.

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Continuous cooling transformation (CCT) diagram of a high strength weathering prefabricated building steel was determined using a DIL805L thermal dilatometer by means of the expansion method combined with metallography hardness method. Effect of cooling rate on microstructure and hardness of the steel was also studied. The results show that the austenite transformation products of the steel are ferrite and pearlite when cooling rate is lower than 3°C/s. In the cooling rate range of 3 to 20°C/s, the mixed microstructure of ferrite, pearlite and bainite can be obtained. When cooling rate is higher than 20°C/s but lower than 100°C/s, the microstructure is composed of ferrite, bainite and martensite. When cooling rate is above 100°C/s, ferrite disappeared completely, and transformation products are bainite and martensite.

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45

Glisic, Dragomir, Abdunnaser Fadel, Nenad Radovic, Djordje Drobnjak, and Milorad Zrilic. "Deformation behavior of two continuously cooled vanadium microalloyed steels at liquid nitrogen temperature." Chemical Industry 67, no. 6 (2013): 981–88. http://dx.doi.org/10.2298/hemind121214015g.

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The aim of this work was to establish deformation behaviour of two vanadium microalloyed medium carbon steels with different contents of carbon and titanium by tensile testing at 77 K. Samples were reheated at 1250?C/30 min and continuously cooled at still air. Beside acicular ferrite as dominant morphology in both microstructures, the steel with lower content of carbon and negligible amount of titanium contains considerable fraction of grain boundary ferrite and pearlite. It was found that Ti-free steel exhibits higher strain hardening rate and significantly lower elongation at 77 K than the fully acicular ferrite steel. The difference in tensile behavior at 77 K of the two steels has been associated with the influence of the pearlite, together with higher dislocation density of acicular ferrite.

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Kučerová, Ludmila, Hana Jirková, and Bohuslav Mašek. "Various Approaches to Accelerated Carbide Spheroidization of 54SiCr Steel." Key Engineering Materials 647 (May 2015): 3–8. http://dx.doi.org/10.4028/www.scientific.net/kem.647.3.

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Changing the lamellar morphology of pearlite to a globular morphology significantly enhances the formability of pearlite-ferrite steels. This change is conventionally achieved by soft annealing. Annealed structures possess low yield strength and excellent ductility and this ensures their good cold formability. The problems of these technologies lie not only in long processing times, but also in high energy consumption which makes the final product quite expensive. The time necessary for cementite spheroidization can be shortened by unconventional heat treatment around Ac1 temperature combined with deformation applied at various processing stages. Several processing methods were utilized for spring steel 54SiCr with ferrite-pearlite original microstructure and lamellar pearlite morphology. The hardness of this structure reached 290 HV10. Three main strategies were tested in this work, using either tensile and compression deformation with following hold applied at heating temperature, temperature cycling around AC1 temperature, or deformation cycles applied at heating temperature. First of all, various heating temperatures in the region of 680-740°C were tested to determine the most suitable heating temperature for this steel. Subsequently, the influence of the character and intensity of applied deformations on cementite spheroidization and ferrite grain refinement were investigated. Carbide morphology and distribution were determined by the means of light and scanning electron microscopy and mechanical properties were determined by hardness measurement. Spheroidized carbides evenly distributed in fine ferrite matrix were obtained after the optimization of processing parameters.

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47

Wang, Yun Long, Yin Li Chen, He Wei, Yi Na Zhao, and Ze Sheng Liu. "Effect of Hot Rolling Process Parameters on Microstructure Transformation and Microstructure of 45MnSiV Steel." Materials Science Forum 944 (January 2019): 265–71. http://dx.doi.org/10.4028/www.scientific.net/msf.944.265.

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The effects of final rolling temperature, cooling rate and deformation on phase transition point, the duration of the phase transition and the pearlite laminar layer of non-quenched and tempered steel 45MnSiV were studied by simulating the process of rolling and post-rolling cooling on Gleeble-3500 thermal simulator and thermal expansion tester. The results show that: the ferrite and pearlite transformation temperature ranges from 510 °C to 700 °C, and the bainite transformation temperature ranges from 400 °C to 500 °C when the steel is continuously cooled at a final rolling temperature of 950 °C, and the martensite transforming temperature is 300 °C under high cooling rate (> 10 °C/s); The pearlite laminar spacing decreases with the decrease of final rolling temperature. It can be seen that the rolling deformation increases the temperature at which the test steel undergoes a phase change at each cooling rate by comparing the results of deformation and no-deformation test at 950 °C. The effect of time advance on the phase transition zone of ferrite and pearlite is particularly obvious, but the effect on the phase transition temperature and time of the bainite and martensite phase transition is not obvious. When the final rolling temperature remains constant, the Rockwell hardness value of the test steel gradually increases, and the pearlite layer spacing decreases with the decrease of ferrite transformation temperature gradually and the increase of the cooling rate.

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Pandit, A. S., and H. K. D. H. Bhadeshia. "Divorced pearlite in steels." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468, no. 2145 (May 2, 2012): 2767–78. http://dx.doi.org/10.1098/rspa.2012.0115.

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Steels containing large carbon concentrations are used particularly when a high hardness is required, for example, in the manufacture of components such as bearings. This, however, makes it difficult to shape or machine the alloys during the process of component manufacture unless they are first heat-treated into a softened condition. One method of achieving this economically is to generate a microstructure known as divorced pearlite, in which ferrite and cementite grow from the austenite in a non-cooperative manner, leading to a final microstructure that consists of coarse, spherical particles of cementite dispersed in a matrix of ferrite. This is in contrast to the harder lamellar pearlite which normally develops when high-carbon steels are cooled. The theoretical framework governing the transition from the divorced to the lamellar form is developed and validated experimentally.

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Dlouhý, Jaromir, Daniela Hauserova, and Zbysek Novy. "Shape Evolution of Cementite during Accelerated Carbide Spheroidisation." Materials Science Forum 782 (April 2014): 117–22. http://dx.doi.org/10.4028/www.scientific.net/msf.782.117.

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Pearlite spheroidisation of 100CrMn6 steel was investigated. This process is well known and studied during conventional soft annealing. Presented paper describes cementite lamellae fragmentation during accelerated carbide spheroidisation. Mechanism of cementite lamellae fragmentation during conventional soft annealing depends on carbon and iron diffusion in ferrite-cementite system. On the other hand, accelerated carbide spheroidisation relies on partial pearlite austenitization and backward austenite decomposition. Aim of presented experiments was to examine shape evolution of cementite particles during transition from lamellar to globular form. Pearlite spheroidisation is normally quantified by image analysis of 2D metallographic section. Conventional metallographic observation was used for globular-lamellar particle ratio estimation. However, whole lamellae observation is necessary for spheroidisation process revelation. Ferrite matrix deep etching and cementite separation was performed to study morphological aspects of acceolerated carbide spheroidisation.

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50

Park, Myeong-heom, Akinobu Shibata, and Nobuhiro Tsuji. "Effect of Grain Size on Mechanical Properties of Dual Phase Steels Composed of Ferrite and Martensite." MRS Advances 1, no. 12 (2016): 811–16. http://dx.doi.org/10.1557/adv.2016.230.

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ABSTRACTIt is well-known that dual phase (DP) steels composed of ferrite and martensite have good ductility and plasticity as well as high strength. Due to their excellent mechanical properties, DP steels are widely used in the industrial field. The mechanical properties of DP steels strongly depend on several factors such as fraction, distribution and grain size of each phase. In this study, the grain size effect on mechanical properties of DP steels was investigated. In order to obtain DP structures with different grain sizes, intercritical heat treatment in ferrite + austenite two-phase region was carried out for ferrite-pearlite structures having coarse and fine ferrite grain sizes. These ferrite-pearlite structures with coarse and fine grains were fabricated by two types of heat treatments; austenitizing heat treatment and repetitive heat treatment. Ferrite grain sizes of the specimens heat-treated by austenitizing and repetitive heat treatment were 47.5 µm (coarse grain) and 4.5 µm (fine grain), respectively. The ferrite grain sizes in the final DP structures fabricated from the coarse-grained and fine-grained ferrite-pearlite structures were 58.3 µm and 4.1µm, respectively. The mechanical behavior of the DP structures with different grain sizes was evaluated by an uniaxial tensile test at room temperature. The local strain distribution in the specimens during tensile test was obtained by a digital image correlation (DIC) technique. Results of the tensile test showed that the fine-grained DP structure had higher strength and larger elongation than the coarse-grained DP structure. It was found by the DIC analysis that the fine-grained DP structure showed homogeneous deformation compared with the coarse-grained DP structure.

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Journal articles on the topic 'Ferrite-pearlite'

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