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A. Saeed-Akbari L. Mosecker A. Schwedt W. Bleck 《Metallurgical and Materials Transactions A》2012,43(5):1688-1704
Thermodynamic stacking fault energy (SFE) maps were developed using the subregular solution model for the Fe-Mn-Al-C system.
These maps were used to explain the variations in the work-hardening behavior of high-manganese steels, both through experiments
and by comparison with the published data. The suppression of the transformation induced plasticity (TRIP) mechanism, the
similarity between the shape of the work-hardening rate diagrams for the produced iso-SFE materials, and an earlier onset
of stage C of work hardening by decreasing SFE were shown to be efficiently predictable by the given mechanism maps. To overcome
the limitations arising from studying the deformation response of high-manganese steels by SFE values alone, for example,
the different work-hardening rate of iso-SFE materials, an empirical criterion for the occurrence of short-range ordering
(SRO) and the consequently enhanced work-hardening, was proposed. The calculated values based on this criterion were superimposed
on the thermodynamics-based mechanism maps to establish a more accurate basis for material design in high-manganese iron-based
systems. Finally, the given methodology is able to clarify the work-hardening behavior of high-manganese twinning induced
plasticity (TWIP) steels across an extensive range of chemical compositions. 相似文献
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Hossein Mehrara Dmitry G. Eskin Roumen H. Petrov Mehdi Lalpoor Laurens Katgerman 《Metallurgical and Materials Transactions A》2014,45(3):1445-1456
A technique for measuring the linear contraction during and after solidification of low-alloy steel was developed and used for examination of two commercial low-carbon and low-alloy steel grades. The effects of several experimental parameters on the contraction were studied. The solidification contraction behavior was described using the concept of rigidity in a solidifying alloy, evolution of the solid fraction, and the microstructure development during solidification. A correlation between the linear contraction properties in the solidification range and the hot crack susceptibility was proposed and used for the estimation of hot cracking susceptibility for two studied alloys and verified with the real casting practice. The technique allows estimation of the contraction coefficient of commercial steels in a wide range of temperatures and could be helpful for computer simulation and process optimization during continuous casting. 相似文献
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Two medium carbon low-alloy MnSiCrB cast steels containing different Cu contents (0.01 wt pct and 0.62 wt pct) were designed,
and the effect of Cu on the mechanical properties and corrosion–abrasion wear behavior of the cast steels was studied. The
results showed that the low-alloy MnSiCrB cast steels obtained excellent hardenability by a cheap alloying scheme. The microstructure
of the MnSiCrB cast steels after water quenching from 1123 K (850 °C) consists of lath martensite and retained austenite.
After tempering at 503 K (230 °C), carbides precipitated, and the hardness of the cast steels reached 51 to 52 HRC. The addition
of Cu was detrimental to the ductility and impact toughness but was beneficial to the wear resistance in a corrosion–abrasion
wear test. The MnSiCrB cast steel with Cu by the simple alloying scheme and heat treatment has the advantages of being high
performance, low cost, and environmentally friendly. It is a potential, advanced wear-resistant cast steel for corrosion–abrasion
wear conditions. 相似文献
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《钢铁研究学报(英文版)》2011,(Z1):72-79
After research and development for decades,low-alloy high-strength steels have been widely used and playing an important role in economy.This article introduces,from the perspective of environmental protection,the Baosteel’s latest progress of low-alloy high-strength steels continuously innovated with the focus of achieving high-strength,high-toughness,long service life and versatile functions,and with the aim of providing energy-saving and pollution-reduction solutions to down-stream sectors. 相似文献
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On Peritectic Reactions and Transformations in Low-Alloy Steels 总被引:1,自引:0,他引:1
Differential thermal analysis (DTA) experiments on low-alloy steels with varying C, Si, Cr, and Mo contents indicated an increase
in the difference between the liquidus and peritectic temperatures during solidification with the decrease in C and increase
in Mo contents. In a number of the quenched samples, massive transformations of ferrite to austenite were observed. Electron
microprobe analysis of the diffusion across a massive transformation front, along with the high growth rates estimated, gives
strong reason to believe that these growths are uncontrolled by diffusion. As ferrite transforms to austenite during the peritectic
reaction, shrinkage in volume occurs, causing elastic straining at the interface separating the two phases. It was shown through
thermodynamic analysis of the equilibrium at the triple point that the increase in energy of the two phases due to this strain
can result in undercooling below the equilibrium peritectic temperature and decreases in the equilibrium peritectic concentrations. 相似文献
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Byoungchul Hwang Chang Gil Lee Sung-Joon Kim 《Metallurgical and Materials Transactions A》2011,42(3):717-728
High-strength low-alloy (HSLA) steels were fabricated by varying thermomechanical processing conditions such as rolling and
cooling conditions in the intercritical region, and the low-temperature toughening mechanism was investigated in terms of
microstructure and the associated grain boundary characteristics. The steels acceleratedly cooled to relatively higher temperature
had lower tensile strength than those acceleratedly cooled to room temperature due to the increased volume fraction of granular
bainite or polygonal ferrite (PF) irrespective of rolling in the intercritical region, while the yield strength was dependent
on intercritical rolling, and start and finish cooling temperatures, which affected the formation of PF and low-temperature
transformation phases. The steel rolled in the intercritical region and cooled to 673 K (400 °C) provided the best combination
of high yield strength and excellent low-temperature toughness because of the presence of fine PF and appropriate mixture
of various low-temperature transformation phases such as granular bainite, degenerate upper bainite (DUB), lower bainite (LB),
and lath martensite (LM). Despite the high yield strength, the improvement of low-temperature toughness could be explained
by the reduction of overall effective grain size based on the electron backscattered diffraction (EBSD) analysis data, leading
to the decrease in ductile-to-brittle transition temperature (DBTT). 相似文献
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Cupertino-Malheiros L. Oudriss A. Thébault F. Piette M. Feaugas X. 《Metallurgical and Materials Transactions A》2023,54(4):1159-1173
Metallurgical and Materials Transactions A - Structural characterization of ten low-alloy tempered martensitic steels of varied composition (C, Cr, Mo, Mn, and V contents) and tempering temperature... 相似文献
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A 0.4 pct C-2 pct Si-1 pct Cr-1 pct Mo steel was quenched and tempered at 773 K (500 °C) and deformed by multi-pass caliber rolling (i.e., warm tempforming). The microstructures and the mechanical properties of the warm tempformed steels were investigated as a function of the rolling reduction. At rolling reductions of more than 28 pct, not only extension of the martensite blocks and/or the packets in the rolling direction (RD) but also a grain subdivision became more significant, and an ultrafine elongated grain (UFEG) structure with a strong ??110??//RD fiber deformation texture was formed after 78 pct rolling. The tensile deformation behavior became significantly anisotropic in response to the evolution of UFEG structure. The longitudinal yield strength (??y) of the quenched and tempered sample increased from 1480 to 1860 MPa through the 78 pct rolling, while the transverse ??y leveled off at around 1600 MPa up to 28 pct rolling. The transverse true fracture stress was also markedly degraded in contrast to the longitudinal one. Charpy impact properties were enhanced at a rolling reduction of 52 pct or more. The 52 pct-rolled sample underwent a ductile-to-brittle transition in the temperature range from 333 K to 213 K (60 °C to ?60 °C), while the 78 pct-rolled sample showed an inverse temperature dependence of the impact toughness because of brittle delamination. The tensile and Charpy impact properties are discussed in association with the microstructural evolution. 相似文献
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利用旋转弯曲疲劳试验方法对比研究了新开发的两种转向节用贝氏体型非调质钢的高周疲劳性能。结果表明, 两种不同碳含量的贝氏体型非调质钢具有细小均匀的贝氏体铁素体+M-A岛组成的粒状贝氏体组织;两者具有相当的强度水平和疲劳性能,但其疲劳性能低于同等强度水平的调质钢。与锻态相比,正火处理后,试验料的抗拉强度和疲劳强度均有一定程度的降低,但屈强比和疲劳极限比明显提高。对疲劳断口的分析表明,试验料的疲劳裂纹均起源于表面基体,疲劳裂纹以准解理机制扩展。裂纹扩展速率试验表明,含碳量较低的试验料的疲劳裂纹扩展速率da/dN明显低于含碳量较高的试验料。 相似文献
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Metallurgist - A detailed study is made using original methods of kinetic features of nanosize niobium carbonitride precipitate formation in relation to metal temperature and deformation regimes on... 相似文献
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The hot deformation behavior of 55SiMnMo steel was studied by hot isothermal compression tests at 950 — 1 100 °C and strain rates of 0.01 — 10s?1 using a Gleeble 3500 thermal simulation machine. Experimental results show that the peak stress increases with decreasing deformation temperature and increasing strain rate. When the strain rate = 0.01s?1, or when = 0.1s?1 and the deformation temperature T ≥ 1000 °C, the dynamic recrystallization (DRX) of 55SiMnMo steel occurs. The hot flow stress constitutive equation, peak strain equation, as well as critical stress and strain for DRX initiation are obtained based on the experimental data. A comparison between the theoretical and experimental results verifies the reliability of the flow stress equation. 相似文献
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Hu Chengyang Wu Kaiming Trotsan A. Li Yu Isayev O. Hress O. Rodionova I. 《Metallurgist》2016,60(7-8):888-895
Metallurgist - One of the main tasks of steelmaking is to obtain the necessary thermodynamic conditions that ensure fine and homogeneous solidified microstructure. The relatively economical... 相似文献