Journal articles: 'Ultra-high strength steel'

1

YASUNO, TAKUYA, KAZUHIKO KURIBAYASHI, and TADASHI HASEGAWA. "Ultra-High Strength Steel." Sen'i Gakkaishi 48, no. 9 (1992): P489—P495. http://dx.doi.org/10.2115/fiber.48.9_p489.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Hietala, Mikko, Antti Järvenpää, Markku Keskitalo, and Kari Mäntyjärvi. "Bending Strength of Laser-Welded Sandwich Steel Panels of Ultra-High Strength Steel." Key Engineering Materials 786 (October 2018): 286–92. http://dx.doi.org/10.4028/www.scientific.net/kem.786.286.

Full text

Abstract:

The study was performed to investigate the bending resistance of laser-welded sandwich panels (Vf-core). The main aim of the study was to determine the effect of the tensile strength on bending strength of the panel structures. Panels were manufactured using an ultra-high strength (UHS) and low strength (LS) steels with yield strengths of 1200 and 200 MPa, respectively. Secondly, the bending strength of the panel structures was compared with the conventional sheet steels to estimate the possibilities for weight reduction. Results showed that the UHS steel panels had significantly higher bending strength than panels of the LS steel. The bending strength in the weakest loading direction of the UHS panel was approximately four times higher than the one of LS steel panel. The panels made with UHS steel faceplates and LS steel cores had better bending strength than LS steel panels. In comparison to UHS sheet steel, 30% weight saving is estimated by using the geometry optimized UHS steel panel.

APA, Harvard, Vancouver, ISO, and other styles

3

Väisänen, Anu, Kari Mäntyjärvi, and Jussi A. Karjalainen. "Bendability of Ultra-High-Strength Steel." Key Engineering Materials 410-411 (March 2009): 611–20. http://dx.doi.org/10.4028/www.scientific.net/kem.410-411.611.

Full text

Abstract:

Utilisation of ultra-high-strength (UHS) steels is rapidly spreading from the automotive industry into many other application areas. It is necessary to know how these materials behave in common production processes such as air bending. The bendability of UHS steels is much lower compared to normal and high-strength construction steels. In this work, experimental tests were carried out using complex phase (CP) bainitic-martensitic UHS steels (YS/TS 960/1000 and 1100/1250) and S650MC HS steel in order to inspect material bendability and possible problems in the bending process. Mechanical and geometrical damages were registered and classified. The bending method used was air bending and press brake bending with an elastic lower die. The FE analysis was used to understand the stress state at different points in the material and build-up of failure. As UHS steels cannot stand large local strains, a large radius must be used in air bending. The results show that even when a large radius is used in air bending, the strain is not evenly distributed; there is a clear high strain area in the middle of the bend. It was also possible to simulate the other phenomena occurring in experimental tests, such as losing contact with the punch and ‘nut-like’ geometry, using FE analysis. Experimental test results also show that by using an elastic lower die, it is possible to avoid unwanted phenomena and obtain an almost 50% smaller punch radius, but the required force is 50% bigger than that required in air bending.

APA, Harvard, Vancouver, ISO, and other styles

4

Chen, Meng Yang, Bo Ming Hwuang, and Jer Ren Yang. "Microstructural Characterizations of Ultra-High Strength Steel Bars." Advanced Materials Research 168-170 (December 2010): 796–804. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.796.

Full text

Abstract:

Steel bars used in high-rising building were developed by the addition of V and Nb in medium carbon steels. In this study, two steel bars with different diameters (16 mm and 36 mm) were analyzed via optical and transmission electron microscopy (OM and TEM)., the microstructures of the steels studuied consist of ferrite and pearlite the same as those of the conventional steel bars, but they possess higher yield strengths (over 685 MPa) in combination of considerable elongations (above 10%). The results of transmission electron microscopy reveals that the copious nano-sized (about 20 nm) carbides were interphase-precipitated in ferrite and that the inter-lamellar spacings of pearlite were extra fine, about with a scale of 100 nm. It has been estimated that the small carbides and fine pearlite provide yield strengths, approximately 300 MPa and 800 MPa, respectively. In addition, the volume fraction of ferrite was up to 40%, which offered sufficient soft phase to experience external stress. The results of tensile tests for the steels studied demonstrat that the amount of strain can be up to 1.4% as a yield stress is reached, and the apparent yield point and plateau are present in the stress-strain curves.

APA, Harvard, Vancouver, ISO, and other styles

5

Arola, Anna Maija, Kari Mäntyjärvi, and Jussi A. Karjalainen. "FEM - Modeling of Bendability of Ultra-High Strength Steel." Key Engineering Materials 549 (April 2013): 333–39. http://dx.doi.org/10.4028/www.scientific.net/kem.549.333.

Full text

Abstract:

Ultra-high strength steels have been widely used in different industrial applications. It is necessary to understand the behavior of these materials in common forming processes such as air bending. It is known that the bendability of ultra-high strength steels is lower than other high-strength steels but what are yet to be discovered are the parameters that define the limits of bendability of these steels. The aim of this study was to investigate the factors affecting the bendability of ultra-high strength steel using optical strain measurements and FEM-modeling of the bending process. By using the true stress-strain relation measured by optical strain measuring system the bendability of ultra-high-strength steel was modeled fairly accurately. As a result, it was noted that the strain distribution at the bend of a steel possessing better uniform strain was more widely distributed and there were no highly localized strains. On the other hand as the failure occurred the strains were considerably smaller than the true failure strain of the material in uniaxial tension. As a conclusion it was stated that the ability to withstand the localization of deformation might describe the bendability of ultra-high-strength steel better than the values of the uniform or true failure strain in uniaxial tension test.

APA, Harvard, Vancouver, ISO, and other styles

6

Haiko, Oskari, Kati Valtonen, Antti Kaijalainen, Vahid Javaheri, and Jukka Kömi. "High-stress abrasive wear characteristics of ultra-high strength press-hardening steel." Tribologia - Finnish Journal of Tribology 39, no. 3−4 (December 31, 2022): 32–41. http://dx.doi.org/10.30678/fjt.122836.

Full text

Abstract:

Ultra-high strength steels are widely utilized in many applications operating in harsh abrasive wear conditions. For instance, the machineries used in mining and mineral handling or in agricultural sector require robust, but cost-effective wear-resistant materials. Steels provide excellent combination of mechanical properties and usability. This study encompasses mechanical and wear testing of an experimental medium-carbon press-hardening steel. The as-received material was austenitized at two different temperatures and quenched in water. Additionally, low-temperature tempering was applied for one variant. In total, three variants of the press-hardening steel were produced. Microstructural characterization and mechanical testing were conducted for the steel samples. The wear testing was carried out with high-stress abrasive method, in which the samples were rotated inside a crushed granite bed. A commercial 400 HB grade wear-resistant steel was included in the wear testing as a reference. The experimental steel showed very high mechanical properties reaching tensile strength up to 2600 MPa with hardness of 750 HV10. Wear testing resulted in only minimal differences between the three variants indicating that the improved impact toughness by tempering did not significantly affect the wear resistance. The reference steel had nearly two times greater mass loss compared to the higher hardness press-hardening steels. Microhardness measurements on the worn surface showed drastic increase in hardness for the deformed structure for all samples. It was concluded that even the high-hardness martensitic steels exhibit notable wear surface work-hardening. Therefore, hardness was determined to be the most significant factor affecting the wear performance of studied steels.

APA, Harvard, Vancouver, ISO, and other styles

7

Zhang, Ju, Chang Wang Yan, and Jin Qing Jia. "Compressive Strength and Splitting Tensile Strength of Steel Fiber Reinforced Ultra High Strength Concrete (SFRC)." Applied Mechanics and Materials 34-35 (October 2010): 1441–44. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.1441.

Full text

Abstract:

This paper investigates the compressive strength and splitting tensile strength of ultra high strength concrete containing steel fiber. The steel fibers were added at the volume fractions of 0%, 0.5%, 0.75%, 1.0% and 1.5%. The compressive strength of the steel fiber reinforced ultra high strength concrete (SFRC) reached a maximum at 0.75% volume fraction, being a 15.5% improvement over the UHSC. The splitting tensile strength of the SFRC improved with increasing the volume fraction, achieving 91.9% improvements at 1.5% volume fraction. Strength models were established to predict the compressive and splitting tensile strengths of the SFRC. The models give predictions matching the measurements. Conclusions can be drawn that the marked brittleness with low tensile strength and strain capacities of ultra high strength concrete (UHSC) can be overcome by the addition of steel fibers.

APA, Harvard, Vancouver, ISO, and other styles

8

Hlebová, Stanislava, and Ladislav Pešek. "Toughness of Ultra High Strength Steel Sheets ." Materials Science Forum 782 (April 2014): 57–60. http://dx.doi.org/10.4028/www.scientific.net/msf.782.57.

Full text

Abstract:

Currently only few methods exist for thin steel sheet testing, especially based on fracture mechanics concept. Charpy impact test is one of the most used method for testing notch toughness and fracture behaviors because of the simplicity and the other advantages [. This article deals with toughness testing of automotive ultra high strength steel sheets (UHSS). Several standard types of toughness test that generate data for specific loading conditions and/or component design approaches exist. Two definition of toughness will be discussed: i) Charpy V-notch toughness, method includes joining of thin steel sheets to one compact unit and ii) material (tensile) toughness [. Two steels were used, DP1000 and 1400M of 1,8 mm thickness and two joining techniques: bonding with adhesives and joining with holders. Effect of material, joining technology, structural adhesives, and number of joined plates on the toughness values was quantified at the room temperature. Toughness of steels by the tensile test was added for comparison. Fracture surface was observed using scanning electron microscope analysis.

APA, Harvard, Vancouver, ISO, and other styles

9

Kah, Paul, Markku Pirinen, Raimo Suoranta, and Jukka Martikainen. "Welding of Ultra High Strength Steels." Advanced Materials Research 849 (November 2013): 357–65. http://dx.doi.org/10.4028/www.scientific.net/amr.849.357.

Full text

Abstract:

The ongoing need to reduce the weight of products while increasing strength has resulted in new generation steel manufacturing using special heat treatments to produce High Strength Steels (HSS) and Ultra High Strength Steels (UHSS) with up to 1700 MPa tensile strength. The high strength level of these steels makes it possible to produce structures with a considerable weight and cost reduction, and such steels have been adopted in the automotive industry and for mobile heavy equipment. Welding of UHSS is, however, not without its complications and welding processes for these steels need careful attention. For instance, their high susceptibility to cracking and Heat Affected Zone (HAZ) softening are risks that need to be borne in mind when choosing welding parameters. This research work discusses the difficulties and challenges of successful welding of UHSS. Common welding methods used in welding of UHSS are briefly reviewed to gain a better understanding of the effects of different welding parameters and methods. The paper finds that UHSS can be satisfactorily welded with laser welding, electron beam welding, resistance welding, and conventional arc welding methods, but the quality of the weld is dependent on appropriate control of several parameters and variables of the welding processes.

APA, Harvard, Vancouver, ISO, and other styles

10

Liu, Zhi Yong, Xin Lai He, Shan Wu Yang, and Qiang Xue Zhou. "Ultra-Low Carbon High Strength Weathering Steels." Advanced Materials Research 317-319 (August 2011): 236–39. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.236.

Full text

Abstract:

The ultra-low carbon high strength weathering steel was trial manufactured. By Optical micrographs observation, scanning electronic microscope (SEM), transmission electronic microscope (TEM), accelerated corrosion test, the corrosion resistant performance of test steel and CortenB steel were studied. The results showed that yield strength, tensile strength, elongation and -40 °C impact energy of test steel reached 510MPa, 600MPa, 22% and 115J, respectively. Corrosion resistance of test steel was superior to that of CortenB. The microstructure of ferrite and bainite, quickly forming adhesive dense rust layers to improve the corrosion resistance of test steel.

APA, Harvard, Vancouver, ISO, and other styles

11

Hietala, Mikko, Markku Keskitalo, and Antti Järvenpää. "The Comparison between Mechanical Properties of Laser-Welded Ultra-High-Strength Austenitic and Martensitic Steels." Key Engineering Materials 841 (May 2020): 132–37. http://dx.doi.org/10.4028/www.scientific.net/kem.841.132.

Full text

Abstract:

The paper investigates experimentally the usability of ultra-high-strength stainless steel and abrasion resistant steel in laser-welded sandwich structures. The fatigue and shear strength of laser joints were investigated using lap joints that were welded using two very different energy inputs. Also the effect of multiple weld tracks was investigated. The properties of separate laser welds were characterized by hardness testing and optical microscopy. Results of the hardness measurements showed that there was softened area at heat-affected-zone and weld metal of the ultra-high-strength stainless steel welds. AR steels weld metal was harder than base metal and there was softened zone in heat-affected-zone of the weld. The shear strength of tested single weld joints of the ultra-high-strength stainless steel was higher compared abrasion resistant steel single weld joints, but stronger joint can be made with multiple weld seams for abrasion resistant steel. Fatigue strength of investigated ultra-high-strength stainless steel lap joint was lower than fatigue strength of abrasion resistant steel lap joint in the low-cycle regime, but there was no practical difference in fatigue limit (10e7 cycles).

APA, Harvard, Vancouver, ISO, and other styles

12

Sugimoto, Koh Ichi, Junji Tsuruta, and Sung Moo Song. "Fatigue Strength of Formable Ultra High-Strength TRIP-Aided Steels with Bainitic Ferrite Matrix." Key Engineering Materials 345-346 (August 2007): 247–50. http://dx.doi.org/10.4028/www.scientific.net/kem.345-346.247.

Full text

Abstract:

Formable ultra high-strength TRIP-aided steel with bainitic ferrite matrix structure (TBF steel) contributes to a drastic weight reduction and an improvement of crash safety of automobile. In this study, fatigue strength of 0.2%C-1.5%Si-1.5%Mn TBF steels was investigated. High fatigue limit was achieved in TBF steels austempered at 400-450oC, containing a large amount of stable retained austenite. The fatigue limit was linearly related with mobile dislocation density, as well as TRIP effect of retained austenite. When compared to conventional martensitic steel, the TBF steel exhibited lower notch-sensitivity or higher notched fatigue performance. Complex additions of 0.5%Al, 0.05%Nb and 0.2%Mo considerably improved the notched fatigue performance, as well as the smooth fatigue strength. This was associated with the stabilized retained austenite and refined microstructure which suppress fatigue crack initiation and/or propagation.

APA, Harvard, Vancouver, ISO, and other styles

13

Garrison, Warren M. "Cobalt and the Toughness of Steel." Materials Science Forum 710 (January 2012): 3–10. http://dx.doi.org/10.4028/www.scientific.net/msf.710.3.

Full text

Abstract:

In developing compositions for new ultra-high strength steels it is important to understand the effects of alloying additions on the microstructure, strength and fracture resistance. Cobalt has been widely used in the development of high toughness ultra-high strength steels and the effects of cobalt on the strength of steels has been studied extensively but there is remarkably little known about how cobalt influences toughness. In this article are reviewed the effects of cobalt on the toughness of steel. The literature suggests that cobalt in solid solution will act to raise the ductile-to-brittle transition temperature but that it can act to increase the upper-shelf toughness of steel.

APA, Harvard, Vancouver, ISO, and other styles

14

Tohgo, Keiichiro, Tomoya Ohguma, Yoshinobu Shimamura, and Yoshifumi Ojima. "Influence of Strength Level of Steels on Fatigue Strength and Fracture Morphology of Spot Welded Joints." Key Engineering Materials 462-463 (January 2011): 94–99. http://dx.doi.org/10.4028/www.scientific.net/kem.462-463.94.

Full text

Abstract:

In this paper, fatigue tests and finite element analyses are carried out on spot welded joints of mild steel (270MPa class) and ultra-high strength steel (980MPa class) in order to investigate the influence of strength level of base steels on fatigue strength and fracture morphology of spot welded joints. From the fatigue tests the following results are obtained: (1) Fatigue limit of spot welded joints is almost the same in both steels. (2) Fatigue fracture morphology of spot welded joints depends on the load level in the ultra-high strength steel, but not in the mild steel. From discussion based on the finite element analyses the following results are obtained: (3) The fatigue limit of spot welded joints can be predicted by stress intensity factors for a nugget edge, fracture criterion for a mixed mode crack and threshold value for fatigue crack growth in base steel. (4) Plastic deformation around a nugget in spot welded joints strongly affects the fatigue fracture morphology.

APA, Harvard, Vancouver, ISO, and other styles

15

Májlinger, Kornél, Levente T. Katula, and Balázs Varbai. "Prediction of the Shear Tension Strength of Resistance Spot Welded Thin Steel Sheets from High- to Ultrahigh Strength Range." Periodica Polytechnica Mechanical Engineering 66, no. 1 (December 22, 2021): 67–82. http://dx.doi.org/10.3311/ppme.18934.

Full text

Abstract:

The tensile strength of newly developed ultra-high strength steel grades is now above 1800 MPa, and even new steel grades are currently in development. One typical welding process to join thin steels sheets is resistance spot welding (RSW). Some standardized and not standardized formulas predict the minimal shear tension strength (STS) of RSWed joints, but those formulas are less and less accurate with the higher base materials strength. Therefore, in our current research, we investigated a significant amount of STS data of the professional literature and our own experiments and recommended a new formula to predict the STS of RSWed high strength steel joints. The proposed correlation gives a better prediction than the other formulas, not only in the ultra-high strength steel range but also in the lower steel strength domain.

APA, Harvard, Vancouver, ISO, and other styles

16

Liu, De Gui, Fu Long Chen, Hai Bao Wu, Ji Zhen Li, and Jian Fei Wang. "Spinning Process of D406A Ultra-High Strength Steel." Materials Science Forum 1035 (June 22, 2021): 410–17. http://dx.doi.org/10.4028/www.scientific.net/msf.1035.410.

Full text

Abstract:

D406A steel is a medium-carbon low-alloy steel, which has excellent comprehensive mechanical properties. It is widely used in the production of missiles and rocket barrels. In this paper, the spinning forming limit test and the intermediate heat treatment process of ultra-high-strength steel were used to explore the effect of spinning process and heat treatment on the properties of spinning parts. The research results showed that the reduction amount of the material made the material thinning rate approach the limit thinning rate. The final blank wall thickness was reduced from 15 mm to 3.0 mm when the cracking occurred. It was calculated that the material's power spinning limit thinning rate was 80%. The ferrite matrix after spinning showed a streamline distribution characteristic perpendicular to the thinning direction, and the precipitated carbides were uniformly distributed on the surface of the matrix, which had the characteristics of deformation and extension along the streamline. After the heat treatment, the structure of the spinning parts changed continuously. When the structure was quenched and tempered, the martensitic structure can be obtained, and the tempered martensitic structure was smaller. Furthermore a test piece for ultra-high-strength steel spinning technology has been developed, and the solutions discussed for flanging defects in the actual spinning process, and test data for the actual production of ultra-high-strength steel spinning parts accumulated.

APA, Harvard, Vancouver, ISO, and other styles

17

Järvenpää, Antti, Pentti Karjalainen, and Kari Mäntyjärvi. "Passive Laser Assisted Bending of Ultra-High Strength Steels." Advanced Materials Research 418-420 (December 2011): 1542–47. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.1542.

Full text

Abstract:

Formability of ultra-high strength steels is poor causing problems in bending and stretch forming. The target of this work was to improve the formability of ultra-high strength steel sheets by controlled local laser heat treatments. Three steel grades, a bainitic-martensitic 4 mm DQ960 and two martensitic WR500 with 6 mm and 10 mm thicknesses were heated by controlled thermal cycles using a 4 kW Yb:Yag –laser, followed by self-cooling. Sheets with the thicknesses of 4 and 6 mm were treated on one side only by heating up to the austenitizing temperature. The 10 mm thick WR500 sheet was heat treated separately on the both surfaces by heating to a lower temperature range to produce a shallow tempered layers. The tensile and bendability tests as well as hardness measurements indicated that laser heat treatment can be used to highly improve the bendability locally without significant strength losses.

APA, Harvard, Vancouver, ISO, and other styles

18

Kwon, Ohjoon, Kyoo Young Lee, Gyo Sung Kim, and Kwang Geun Chin. "New Trends in Advanced High Strength Steel Developments for Automotive Application." Materials Science Forum 638-642 (January 2010): 136–41. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.136.

Full text

Abstract:

The body design with light weight and enhanced safety is a key issue in the car industry. Corresponding to this trend, POSCO is developing various automotive steel products with advanced performance. Conventional advanced high strength steels such as DP and TRIP steels are now expanding their application since the steels exhibit higher strength and ductility than those of conventional solution and precipitation strengthened high strength steels. Efforts have been made to enhance the mechanical performance of these steels such as ductility, hole expansion ratio, deep drawability, etc. Current research is focused on development of extra- and ultra-AHSS. Extra-AHSS are designed to utilize nano-scale retained austenite embedded in fine bainite and martensite. Ultra-AHSS are designed to have austenite as the major phase, and the ductility is enhanced primarily by continuous strain hardening generated during forming. These steels including extra- and ultra-AHSS are believed to be the next generation automotive steels which will replace the existing high strength steels due to their extremely high strength and ductility combinations.

APA, Harvard, Vancouver, ISO, and other styles

19

Lipiäinen, Kalle, Antti Ahola, Tuomas Skriko, and Timo Björk. "Fatigue strength characterization of high and ultra-high-strength steel cut edges." Engineering Structures 228 (February 2021): 111544. http://dx.doi.org/10.1016/j.engstruct.2020.111544.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Zeng, Yan Ping, Hong Mei Fan, Xi Shu Wang, and Xi Shan Xie. "Study on Micro-Mechanism of Crack Initiation and Propagation Induced by Inclusion in Ultra-High Strength Steel." Key Engineering Materials 353-358 (September 2007): 1185–90. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.1185.

Full text

Abstract:

Specially designed SEM in-situ tensile and fatigue tests have been conducted to trace the entire process of crack initiation and propagation till fracture in an ultra-high strength steel MA250. TiN is a typical inclusion and its average size is in the range of 8~10μm in MA250 steel. The micro-mechanism of the effect of TiN inclusion on crack initiation and propagation at tensile and fatigue tests both have been studied in detail. Experimental results show the harmful effect of TiN on tensile and fatigue properties both. This work is helpful to establish the practical life prediction model for the characteristic inclusion parameters in ultra-high strength steel components. It also enlightens us to eliminate TiN in the further development of ultra-high strength steels.

APA, Harvard, Vancouver, ISO, and other styles

21

Wang, Li Jun, and Chun Ming Liu. "Martensitic Stainless Steel as Alternative for Hot Stamping Steel with High Product of Strength and Ductility." Advanced Materials Research 1063 (December 2014): 37–41. http://dx.doi.org/10.4028/www.scientific.net/amr.1063.37.

Full text

Abstract:

Though more and more structural and safety automobile components are manufactured using hot stamping technology for the advantage of excellent shape accuracy while producing ultra high strength parts without any springback.Fewer hot stamping steels are developed except 22MnB5 steel, which exhibits ultra-high strength but limited ductility. Inspired by the application of quenching and partitioning C-Mn-Si steel, the microstructure and properties of a 30Cr13 steel subjected to quenching and partitioning treatment were studied to evaluate the possibility of martensitic stainless steel as alternative for hot stamping steel with high product of strength and ductility. The experiment result shows that, enhanced mechanical properties of Rel=1350MPa, Rm=1740MPa, and A=17.5% can be achieved through appropriate treatment. Due to the unique phase transformation conditions of martensitic stainless steel, processing parameters and corresponding equipments for automobile components manufacturing have to been investigated.

APA, Harvard, Vancouver, ISO, and other styles

22

Ganesh, S., P. Sai Karthik, M. Ramakrishna, A. V. Reddy, S. B. Chandrasekhar, and R. Vijay. "Ultra–high strength oxide dispersion strengthened austenitic steel." Materials Science and Engineering: A 814 (May 2021): 141192. http://dx.doi.org/10.1016/j.msea.2021.141192.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Ochiai, Ikuo, Seiki Nishida, Hiroshi Ohba, Osami Serikawa, and Hiromi Takahashi. "Development of Ultra-High Strength Hypereutectoid Steel Wires." Materia Japan 33, no. 4 (1994): 444–46. http://dx.doi.org/10.2320/materia.33.444.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

MORI, Ken-ichiro. "Hot Stamping of Ultra-High Strength Steel Parts." Journal of the Japan Society for Technology of Plasticity 58, no. 673 (2017): 125–29. http://dx.doi.org/10.9773/sosei.58.125.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Neimitz, Andrzej, Ihor Dzioba, and Teijo Limnell. "Modified master curve of ultra high strength steel." International Journal of Pressure Vessels and Piping 92 (April 2012): 19–26. http://dx.doi.org/10.1016/j.ijpvp.2012.01.008.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Mori, K., P. F. Bariani, B. A. Behrens, A. Brosius, S. Bruschi, T. Maeno, M. Merklein, and J. Yanagimoto. "Hot stamping of ultra-high strength steel parts." CIRP Annals 66, no. 2 (2017): 755–77. http://dx.doi.org/10.1016/j.cirp.2017.05.007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Amraei, Mohsen, Lingjia Zong, Antti Ahola, and Timo Björk. "Bonded CFRP to high strength steels." Rakenteiden Mekaniikka 52, no. 4 (December 31, 2019): 222–35. http://dx.doi.org/10.23998/rm.76267.

Full text

Abstract:

Research on the bond performance of CFRP-strengthened steel have been done for the past years, but it has mainly focused on lower grades of steel. The performance of the bond between ultra-high modulus (UHM) CFRP and high/ultra-high strength steel (HSS/UHSS) is investigated in this paper. A series of experiments have been conducted, with single/double side-strengthened (SSS/DSS) HSS/UHSS with CFRP laminates using Araldite adhesive. It was found that strengthening up to the ultimate strength of the DSS specimens is feasible. However, debonding happens at the ultimate strength of SSS specimens.

APA, Harvard, Vancouver, ISO, and other styles

28

Li, Feng, Fang Zhou, Hong Gang Yang, Jia Shun Lv, Leng Zhang, and Hong Ke Wang. "Experimental Study for Ultra High Strength Strapping Flat Steel." Applied Mechanics and Materials 490-491 (January 2014): 181–85. http://dx.doi.org/10.4028/www.scientific.net/amm.490-491.181.

Full text

Abstract:

Ultra high strength strapping flat steel is used in packaging for papermaking, tobacco, compressed cotton and wool. At present, there is only one company can produce it by Lead bath quenching line. In this paper, the feasibility to produce new ultra high strength strapping flat steel of which tensional strength is 1350 MPa and elongation is 12% by continuous annealing process was investigated. The experiment result of steelmaking, hot rolling, pickling, cold rolling and continues heat treatment showed, the steel could be got using new chemical composition. The microstructure and X-ray diffraction spectrum of the steel showed, the steel was strengthened and toughened by martensite and retained austenite. The effect of continues heat treatment on microstructure and mechanical properties was discussed.

APA, Harvard, Vancouver, ISO, and other styles

29

Abe, Yohei, Takato Saito, Ken-Ichiro Mori, and Toru Kato. "Mechanical clinching with dies for control of metal flow of ultra-high-strength steel and high-strength steel sheets." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 232, no. 4 (February 1, 2017): 644–49. http://dx.doi.org/10.1177/0954405416683429.

Full text

Abstract:

Ultra-high-strength steel sheets having a tensile strength of more than 1 GPa and a low ductility were joined by mechanical clinching with dies for control of metal flow. The bottom angle of the die was modified to increase interlocking between the sheets under avoidance of the sheet fracture. The effect of the die shape on metal flow in the sheet combination including an ultra-high-strength steel sheet was investigated by the finite element simulation and the experiment. As the tensile strength of the steel sheets increased, the joining range was narrow due to low ductility of the sheets. The static and fatigue strengths of the mechanically clinched joints were compared with those of the welded joints. Although the static loads of the mechanically clinched joints were smaller than those of the resistance spot welded joints in both tension-shearing and cross-tension tests, the fatigue loads of the clinched joints were larger. It was found that the mechanically clinched joint has superior fatigue strength.

APA, Harvard, Vancouver, ISO, and other styles

30

Wang, Kai, Zhi Bin Wang, Pei Xing Liu, and Yi Sheng Zhang. "Influences of Austenitization Parameters on Properties of Martensitic Stainless Steel in Hot Stamping." Advanced Materials Research 1063 (December 2014): 194–97. http://dx.doi.org/10.4028/www.scientific.net/amr.1063.194.

Full text

Abstract:

Due to high temperature and inevitable contact with air, strong oxidation and decarburization of the bare steel exist in hot stamping of ultra-high strength steels. Martensitic stainless steel could be a potential solution with its corrosion resistance and high strength. In this paper, the influences of austenitization temperature (850 to 1000 °C) and time (3 to 10 min) on final properties of 410 martensitic stainless steel were investigated, to obtain an ultra-high strength up to 1500MPa. The hot stamping of 410 steel is simulated by compression tests with a flat die. Mechanical properties of blanks after hot stamping process were detected by tensile tests. Results show that the final strength of 410 steel increases and the plasticity decreases, with the increase of austenitization temperature and time. After austenitization at 1000 °C for 5-10 min, an ultimate tensile strength up to 1500MPa is obtained with a martensite dominated microstructure.

APA, Harvard, Vancouver, ISO, and other styles

31

Amraei, Mohsen, Xiao-Ling Zhao, Timo Björk, and Amin Heidarpour. "Bond characteristics between high/ultra-high strength steel and ultra-high modulus CFRP laminates." Engineering Structures 205 (February 2020): 110094. http://dx.doi.org/10.1016/j.engstruct.2019.110094.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Sugimoto, Kohichi, Shohei Sato, and Goro Arai. "Hot Forging of Ultra High-Strength TRIP-Aided Steel." Materials Science Forum 638-642 (January 2010): 3074–79. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.3074.

Full text

Abstract:

Ultra high-strength TRIP-aided steel consisting of bainitic ferrite matrix and interlath retained austenite films (TBF steel) possesses high toughness and fatigue strength, as well as high resistance against hydrogen embrittlement. In this study, to improve further these mechanical properties, the effects of hot forging and subsequent isothermal transformation holding process (FIT process) on microstructure, retained austenite characteristics, tensile properties and toughness of the TBF steel with chemical composition of 0.4%C, 1.5%Si, 1.5%Mn, 0.5%Cr, 0.2%Mo, 0.05%Nb and 0.5%Al (mass%) were investigated. The FIT process brought on an excellent combination of tensile strength of 1350-1550 MPa and Charpy impact absorbed value of 100-110 J/cm2 in the developed TBF steel, exceeding so much that of SCM440 steel. The excellent combination was mainly caused by (i) refined mixed structure of bainitic ferrite and retained austenite and (ii) the increased mechanical stability of retained austenite due to the FIT process.

APA, Harvard, Vancouver, ISO, and other styles

33

Bao, Jun, Hong Sheng Liu, Zhong Wen Xing, Bao Yu Song, and Yu Ying Yang. "Flow Behavior of Ultra-High Strength Boron Steel at Elevated Temperature." Materials Science Forum 704-705 (December 2011): 191–95. http://dx.doi.org/10.4028/www.scientific.net/msf.704-705.191.

Full text

Abstract:

Ultra-high strength boron steel is widely used in a new hot stamping technology which is hot formed and die quenched simultaneously in order to obtain stamping parts with 1500MPa tensile strength or higher. Tensile experiments were carried out with ultra-high strength boron steel in a range of temperature 500°C~860°Cand strain rate 0.01/s~1/s with the thermal simulation testing machine Gleeble 3800, and the stress-strain curves were obtained. The influences of the deformation temperature and strain rate on the stress-strain curves were analyzed. The results show that hot behavior at elevated temperature of ultra-high strength boron steel consists of strain hardening and dynamic recovery mechanism, which can be accurately described by the mathematic model. Keywords: Ultra-high strength boron steel, hot stamping, hot flow behavior

APA, Harvard, Vancouver, ISO, and other styles

34

Aljabbri, Noor Alhuda Sami, Mohammed Noori Hussein, and Ali Abdulmohsin Khamees. "Performance of Ultra High Strength Concrete Expose to High Rise Temperature." Annales de Chimie - Science des Matériaux 45, no. 4 (August 31, 2021): 351–59. http://dx.doi.org/10.18280/acsm.450411.

Full text

Abstract:

Fire or high temperature is a serious issue to ultra-high-strength concrete (UHSC). Strength reduction of UHPCs may amount to as high as 80 percent after exposure to 800℃. A sum of four UHSC mixes was synthesized and evaluated in this study after getting exposed to extreme temperatures that reach 1000°C. Steel and polypropylene (PP) fibers were used in this experiment. A total of four mixes were made of UHSC without fibres as a control mix (UHSC-0), UHSC with 2% steel fibres (UHSC-S), UHSC with 2% PP fibres (UHSC-P) and UHSC with 1% steel fibres + 1% PP fibres (UHSC-SP). Workability, direct tensile strength, compressive strength, and splitting tensile strength were examined. Particularly, emphasis was devoted to explosive spalling since UHPCs are typically of compact structure and hence more prone to explosive spalling than other concretes. It was determined that the mixture UHSC-SP had high fire resistance. Following exposure to 1000℃, this mixture preserved a residual compressive strength of 36 MPa, splitting tensile strength of 1.62 MPa and direct tensile strength of 0.8 MPa. On the other hand, UHSC-P also had good fire resistance while UHSC-0 and UHSC-S experienced explosive spalling after heating above 200ᴼC. The incorporation of steel fibers in UHSC-S and UHSC-SP mixtures reveals higher tensile and compressive strength findings at different elevated temperatures as compared to UHSC-0 and UHSC-P. In addition, the result of direct tensile strength appears to be lower than splitting tensile strength at different raised temperatures.

APA, Harvard, Vancouver, ISO, and other styles

35

Martinez, M. A., J. Abenojar, J. M. Mota, and R. Calabrés. "Ultra High Carbon Steels Obtained by Powder Metallurgy." Materials Science Forum 530-531 (November 2006): 328–33. http://dx.doi.org/10.4028/www.scientific.net/msf.530-531.328.

Full text

Abstract:

The objective of the present work is to study the manufacturing process of steels with high carbon content (1.5–2.1wt%) obtained by powder metallurgy. The reference material was the Damascus steel, which was employed to manufacture swords named after it and has been widely known due to its very good mechanical properties. The main reasons of the success of this product are: the high carbon content of the initial steel and the thermomechanical treatment (forge and quenching) that ancient iron forgers kept secretly during centuries. Different carbon contents (2 to3 wt%) were added to the same Fe powder matrix (ASC 300), and compacted and sintered steels are heat laminated (750°C) with a reduction of 20%. For 2% carbon content, the result is a steel with yield strength of 450 MPa, Young’s Modulus of 14.3 GPa and hardness of 109 HV(30).

APA, Harvard, Vancouver, ISO, and other styles

36

Hwang, Byoung Chul, Chang Gil Lee, and Sung Hak Lee. "Microstructure and Mechanical Properties of Ultra-High Strength Steel Plates with High Deformability." Materials Science Forum 638-642 (January 2010): 3266–71. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.3266.

Full text

Abstract:

High deformability has been considered as a critical factor of ultra-high strength steel plates subjected to compressive, tensile, and bending deformation induced by large ground movements. In this paper, various dual phase microstructures consisting of soft ferrite and strong low-temperature transformation phases without deformation in the (austenite + ferrite) two-phase temperature region after controlled rolling were introduced and then the mechanical properties were discussed with emphasis on deformability such as yield ratio and uniform elongation. Ultra-high strength steel plates fabricated by a modified thermo-mechanical control process showed lower yield ratio of under 0.75 and higher uniform elongation of 5% as a minimum, as compared to commercial API X100 and X120 grade pipeline steels, without much sacrifice of Charpy impact properties because of an appropriate formation of soft ferrite and strong low-temperature transformation phases.

APA, Harvard, Vancouver, ISO, and other styles

37

Ma, Yu Xi, Bin Guo, Lin Zheng, Chang Song, Chang Ming Liu, and Jun Hui Tao. "Microstructure and Mechanical Properties in Ultra-High Strength Steel with Tensile Strength 1000MPa." Advanced Materials Research 567 (September 2012): 79–87. http://dx.doi.org/10.4028/www.scientific.net/amr.567.79.

Full text

Abstract:

Ultra-high Strength Steel heat process mechanical property energy spectrometer Abstract: Microstructure and mechanical property variation vs. heat process was investigated by means of metallography and electron microscopy in Ultra-high Strength Steel with tensile strength 1000Mpa. The results show that microstructure variation in the steel with tempering temperature increasing is as follows:tempered martensite→main tempered sorbite and a small amount of M/A, at the meantime, growing in quantities and volume of second-phase, always decreasing in strength, firstly increasing and then decreasing in impact energy and elongation. Study on precipitated mechanism of second-phases, the crystal structure and volume of precipitation was characterized by TEM observation and energy spectrometer.

APA, Harvard, Vancouver, ISO, and other styles

38

Abe, Yohei, Ken-Ichiro Mori, and Ryota Kosaka. "Improvement of Fatigue Strength of Hole Edge of Ultra-High Strength Steel Sheet by Punching Process Including Thickening." Key Engineering Materials 716 (October 2016): 428–34. http://dx.doi.org/10.4028/www.scientific.net/kem.716.428.

Full text

Abstract:

The effect of the hole edge shape formed by a punching process including thickening on the fatigue strength of the hole of ultra-high strength steel sheets was investigated. The bending and tensile fatigue tests of the thickened hole edge were performed. For the bending fatigue strength, the high height of hole edge was effective because of high bending stiffness. Although the high tensile stiffness was important for the high tensile fatigue strength, the shape of hole edge was alternative. To increase both the bending and tensile fatigue strengths, a compressive process in rollover of hole edge was added for the thickened sheet having a high bending fatigue strength. It was found that the thickened and compressed hole edge of ultra-high strength steel sheet was effective in improving both the bending and tensile fatigue strengths.

APA, Harvard, Vancouver, ISO, and other styles

39

Ghosh, A., Brajendra Mishra, and Subrata Chatterjee. "Development of Low Carbon Microalloyed Ultra High Strength Steels." Materials Science Forum 500-501 (November 2005): 551–58. http://dx.doi.org/10.4028/www.scientific.net/msf.500-501.551.

Full text

Abstract:

In the present study HSLA steels of varying carbon concentrations, alloyed with Mn, Ni, Cr, Mo, Cu and micro-alloyed with Nb and Ti were subjected to different finish rolling temperatures from 850oC to 750oC in steps of 50oC. The microstructure of the steel predominantly shows martensite. Fine twins, strain induced precipitates in the martensite lath along with e-Cu precipitates are observed in the microstructure. With an increase in carbon content the strength value increases from 1200MPa UTS to 1700MPa UTS with a negligible reduction in elongation. Impact toughness values of 20-26 joules at room temperature and −40oC were obtained in sub-size samples.

APA, Harvard, Vancouver, ISO, and other styles

40

Saeidi, Kamran, Daniel Leon Zapata, Frantisek Lofaj, Lenka Kvetkova, Jon Olsen, Zhijian Shen, and Farid Akhtar. "Ultra-high strength martensitic 420 stainless steel with high ductility." Additive Manufacturing 29 (October 2019): 100803. http://dx.doi.org/10.1016/j.addma.2019.100803.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Li, Qing Shan, Mei Zhang, Chao Bin Huang, Ru Yi Wu, Xue Zhao, Yong Zhong, and Lin Li. "Hot Ductility Behavior of 800MPa Ultra High Strength Niobium Containing Steels." Advanced Materials Research 690-693 (May 2013): 227–32. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.227.

Full text

Abstract:

The hot ductility behavior of 800MPa ultra high strength niobium containing steels has been investigated with Gleeble3500 hot simulator. Tensile test was carried out at 650°C1300°C at a constant true strain rate of 0.001 s1. Experimental results showed that steel A has quite well ductility, and the brittle zone is narrow. Due to pro-eutectoid ferrite film formation along the prior austenite grain boundary at 650°C-750°C, samples showed a loss of hot ductility, and the fracture morphology of the specimens was brittle intercrystalline fracture, indicating the third brittle zone of the steel. However, the third brittle zone can be avoided during continuous casting, if the temperature of straightening could be kept over 800°C.

APA, Harvard, Vancouver, ISO, and other styles

42

Shan, Zhong De, Qin Tai Yan, Chao Jiang, and Wen Juan Rong. "Ultra-High Strength Steel Hot Stamping Technology and Devices." Advanced Materials Research 1063 (December 2014): 237–43. http://dx.doi.org/10.4028/www.scientific.net/amr.1063.237.

Full text

Abstract:

Ultra High Strength Steel (UHSS) hot stamping technology is a special process which can enhance the steel tensile strength to 1500MPa. Appling this technology in producing vehicle structure parts can make car lighter and safer. In China there are more and more automobile enterprises adopt this technology. To master and extend the skill, China Academy of Machinery Science & Technology (CAM) have done systematic research, such as the strengthen mechanism of the steel, hot stamping key devices designing, forming and quenching integrated mould designing, stamping process parameters optimization, etc.. By now, CAM has mastered the mass production technology of vehicle parts, which can guarantee its shape and tensile strength, and produced such typical parts as door-beam, B pillar, etc.. The paper is an introduction of the research work and achievement about UHSS hot stamping developed by CAM.

APA, Harvard, Vancouver, ISO, and other styles

43

NYKÄNEN, T., T. BJÖRK, and R. LAITINEN. "Fatigue strength prediction of ultra high strength steel butt-welded joints." Fatigue & Fracture of Engineering Materials & Structures 36, no. 6 (November 8, 2012): 469–82. http://dx.doi.org/10.1111/ffe.12015.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Arlazarov, Artem, Jean-Christophe Hell, Carla Oberbillig, and Frédéric Kegel. "High Strength High Ductility Low Alloyed Steel." Materials Science Forum 941 (December 2018): 100–105. http://dx.doi.org/10.4028/www.scientific.net/msf.941.100.

Full text

Abstract:

Annealed Martensite Matrix (AMM) concept was studied on two steel grades with low alloyed base composition of Fe-C-Mn-Si and two levels of Nb. Conditions for the thermal treatments were selected based on the experimental dilatometry tests and thermodynamic calculations. Annealing trials with short austempering holding were performed in the laboratory salt pots. Mechanical properties of heat treated steels have been investigated by tensile tests. Associated microstructures have been analyzed using Scanning Electron Microscopy as well as magnetization saturation method for measuring retained austenite fractions. Excellent strength-ductility balance was obtained due to the ultra-fine multiphase structure and high amount of stable retained austenite.

APA, Harvard, Vancouver, ISO, and other styles

45

Lv, Wei, Di Wu, and Zhuang Li. "Development of Laminar Flow Cooling of Ultra-High Strength Ferrite-Bainite Dual Phase Steel." Applied Mechanics and Materials 184-185 (June 2012): 940–43. http://dx.doi.org/10.4028/www.scientific.net/amm.184-185.940.

Full text

Abstract:

In the present paper, controlled cooling in different ways was performed using a laboratory hot rolling mill in ultra-high strength hot rolled ferrite-bainite dual phase (DP) steel. The results have shown that the final microstructures of DP steel comprise ferrite, bainite and a small amount of retained austenite and martensite. DP steel has a tensile strength ranging from 1010 to 1130MPa and yet retains considerable total elongation in the range of 14–17%. The addition of Mn and Nb to DP steel leads to the maximum ultimate tensile strength, yield strength and the product of ultimate tensile strength and total elongation due to the formation of retained austenite and granular bainite structure. Laminar flow cooling after hot rolling results in a significant increase in the quantity of ferrite and bainite due to the suppression of pearlite transformation, and as a result, the present steel possesses high strengths and good toughness.

APA, Harvard, Vancouver, ISO, and other styles

46

Abe, Yohei, Ken Ichiro Mori, Shigehiro Nakanoshita, and Purwo Kadarno. "Direct Punching in Inclined Ultra-High Strength Steel Sheets." Key Engineering Materials 622-623 (September 2014): 1051–57. http://dx.doi.org/10.4028/www.scientific.net/kem.622-623.1051.

Full text

Abstract:

A direct punching of inclined ultra-high strength steel sheets having low ductility was carried out to improve the quality of the sheared edge. In the direct punching of an inclined sheet, the contact between the sheet and punch became gradual because of touch from the bottom edge of the punch, and thus the sheared portion tended to bend in the latter half of punching. As the strength of the sheet increased, defects such as burr and secondary burnished surface were occurred around the sheared edge due to the low ductility. The range of direct punching for sheared edge without defects was shown for the high strength steel sheets. To prevent the occurrence of defects, a punch having inclined bottom was used. In this punch, the contact with the sheet was changed, the uniform contact with the inclined bottom was given. In the punch having the inclined bottom, the secondary burnished surface in the edge of 980 MPa grade steel sheet was prevented.

APA, Harvard, Vancouver, ISO, and other styles

47

Adachi, Yoshitaka, and Kaneaki Tsuzaki. "Ultra Rapid Softening of High Strength Structural Steels by Thermomechanical Treatment." Materials Science Forum 539-543 (March 2007): 4807–12. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.4807.

Full text

Abstract:

This study aims to shorten the softening treatment period as possible in high strength structural steels. The steel used is SCM440 steel. As an initial microstructure, martensite, bainite, pearlite and complicated microstructure consisting of ultrafine polygonal, martensite and equiaxed cementite were extensively examined to understand their softening process on aging at 973K. These initial microstructures were prepared by heat or thermomechanical treatment. Their initial Vickers hardness (Hv(10kgf)) were 634, 281, 219 and 238, respectively. It is noteworthy that within five minutes on aging hardness of the complicated microstructure reached lower than Hv200, while it took more than several hours for other initial microstructures. A quantitative evaluation of microstructures appears to help in understanding the mechanism of the softening kinetics.

APA, Harvard, Vancouver, ISO, and other styles

48

Wang, Haolei, Tao Sun, Chen Tang, and Jiejun Wang. "Experimental and numerical investigation of steel–ultra-high-performance concrete continuous composite beam behavior." Advances in Structural Engineering 23, no. 10 (March 7, 2020): 2220–36. http://dx.doi.org/10.1177/1369433220911140.

Full text

Abstract:

This article proposes a new kind of continuous composite beam that consists of steel box-girder and ultra-high-performance concrete waffle slab. The ultra-high-performance concrete helps increase the ultimate capacity and span of structure while reducing the risk of cracking that occurs with ordinary concrete. In order to investigate the mechanical properties of this new type of composite structure, two scaled specimens were designed and tested. One was a steel–ultra-high-performance concrete continuous composite beam, whereas the other, as a control specimen, was a prestressed steel-concrete continuous composite beam. The test results indicate that the bending capacity of steel–ultra-high-performance concrete continuous composite beam is 1.2 times that of steel-concrete continuous composite beam; the cracking strength of steel–ultra-high-performance concrete continuous composite beam is larger than 20 MPa, much higher than the conventional one; the crack development pattern of steel–ultra-high-performance concrete continuous composite beam has its own characteristics, and the cracks appeared in ultra-high-performance concrete slab dominated by micro-cracks with smaller length are numerous and intensive. A finite element model was developed to predict the behavior of steel–ultra-high-performance concrete continuous composite beam. Comparing the numerical and experimental results indicates that, generally, the numerical model can simulate the structural behavior of steel–ultra-high-performance concrete continuous composite beam reasonably. Based on the numerical model, a series of parameter analyses were performed, which indicate that the strength grade of steel, web, and bottom plate thickness play an important role in improving the bending capacity of steel–ultra-high-performance concrete continuous composite beam; the axial tensile strength of ultra-high-performance concrete, rib, and top plate height of ultra-high-performance concrete slab can enhance the bending capacity to a certain extent.

APA, Harvard, Vancouver, ISO, and other styles

49

Chatterjee, Subrata, S. K. Ghosh, and P. S. Bandyopadhyay. "Thermo-Mechanically Controlled Processed Ultrahigh Strength Steels." Materials Science Forum 783-786 (May 2014): 685–91. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.685.

Full text

Abstract:

A low-carbon, titanium and niobium (Ti-Nb) bearing and a low-carbon titanium, niobium and copper (Ti-Nb-Cu) bearing ultra high strength steel have been thermo-mechanically processed on a laboratory scale unit. Evolution of microstructure and mechanical properties of the above air cooled steels have been studied at different finish rolling temperatures (FRTs). Microstructural characterization reveals largely a mixture of granular bainite and bainitic ferrite along with the precipitation of microalloying carbide/carbonitride particles and/or Cu-rich precipitates. (Ti-Nb) bearing steel yields higher yield strength (1114-1143 MPa) along with higher tensile strength (1591-1688 MPa) and moderate ductility (12-13%) as compared to (Ti-Nb-Cu) bearing steel having yield strength (934-996 MPa) combined with tensile strength (1434-1464 MPa) and similar ductility (13%) for the selected range of 850-750°C FRT. Due to higher strength-ductility combinations, these present investigated steels can be regarded as the replacement material for ballistic applications as well as other sectors like defense, pipeline, cars, pressure vessels, ships, offshore platforms, aircraft undercarriages and rocket motor casings etc. Key words: Thermo-mechanical controlled processing, ultra high strength steel, microstructure, mechanical properties.

APA, Harvard, Vancouver, ISO, and other styles

50

Chen, T. C., Wen Hao Chien, Yuan Tsung Wang, Ching Yuan Huang, Hung Wei Yen, and Hsin Chih Lin. "Hydrogen Assisted Tempered Martensite Embrittlement of Ultra High Strength Martensitic Steel." Materials Science Forum 880 (November 2016): 29–32. http://dx.doi.org/10.4028/www.scientific.net/msf.880.29.

Full text

Abstract:

The demand for new materials that provide excellent structural performance while reducing weight and being cost-effectively manufactured is increasing. For applications with high strength requirements, ultra-high strength steels (UHSS) have been widely used. However, with such a high strength level, UHSS are very sensitive to the hydrogen that could be ease by the tempering process. In this research, the correlation of hydrogen and tempering process on commercial UHSS 15B30 has been studied. Results show that the tensile strength (TS) of as-quenched 15B30 is about 1900MPa. After tempering treatment of the quenched 15B30, the TS decreases from 1600MPa to 1200MPa with tempering temperature increased from 200°C to 400°C. The 15B30 specimens, being subjected to hydrogen charge, exhibit the dramatic reduction of mechanical strengths.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Ultra-high strength steel'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles