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研究了三种不同基体组织的超高强度低合金相变诱发塑性(TRTP)钢中充入的氢量及其对韧性的影响。这些TRIP钢.特别是具有贝氏体铁素体基体组织的TPIP钢,充入的氢量比常规回火马氏体钢要多。这主要与残余奥氏体吸收多量氢溶质有关。TRIP钢、特别是退火马氏体基体组织TRIP钢的氢脆被大大地抑制。可以认为,导致钢中氢脆性低的原因是大量的氢进入了残余奥氏体,均匀细小的组织,残余奥氏体的TRIP效应和出现准韧窝断口。 相似文献
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一、前言近年来对钢中残留奥氏体的作用进行了广泛的研究。对于不同零件和使用条件,控制合理的残留奥氏体含量对性能是有利的。本文针对20CrMnTi钢,C-N共渗后采用不同的热处理工艺,得到不同的残留奥氏体量,用X射线衍射测量残留奥氏体量。并且绘出层深与残留奥氏体分布曲线。试验为研究材料性能与残留奥氏体的关系和对20CrMnTi齿轮钢,以C-N共渗制定热处理工艺,控制残余奥氏体量提供了依据。 相似文献
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冷处理是把钢置于低于室温的适当温度进行冷却,以使淬火后钢中的残余奥氏体变为马氏体。淬火后残余奥氏体含量随着钢中含碳量的增加而增多;钢中含降低Ms点的元素越多,残余奥氏体量也越多;淬火时,冷却介质温度越高,残余奥氏体量越多。 相似文献
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采用三种不同热加工工艺进行了一种C-Mn-Al-Si-Nb钢的轧制,借助扫描电镜、X射线衍射及拉伸实验研究了它的组织及力学行为。结果表明:在控制冷却TRIP(相变诱发塑性)钢工艺、动态相变TRIP钢工艺及贝氏体等温处理工艺下,实验钢分别获得了以较粗大铁素体、细晶铁素体和板条贝氏体为基体,并含有一定残余奥氏体的多相组织。控制冷却TRIP钢强度最低,但同时残余奥氏体稳定性较低,变形过程中转变最多,加工硬化能力较强,延伸率也最高。动态相变TRIP钢中细晶铁素体提高了基体强度,残余奥氏体稳定性较高,变形初期加工硬化能力不足。贝氏体钢基体强度最高,但残余奥氏体稳定性也较高,变形过程中转变量最少,对塑性提升作用有限。 相似文献
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研究了三种不同基体组织的超高强度低合金相变诱发塑性(TRIP)钢中充入的氢量及其对韧性的影响。这些TRIP钢,特别是具有贝氏体铁素体基体组织的TPIP钢,充入的氢量比常规回火马氏体钢要多。这主要与残余奥氏体吸收多量氢溶质有关。TRIP钢、特别是退火马氏体基体组织TRIP钢的氢脆被大大地抑制。可以认为,导致钢中氢脆性低的原因是大量的氢进入了残余奥氏体,均匀细小的组织,残余奥氏体的TRIP效应和出现准韧窝断口。 相似文献
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《塑性工程学报》2013,(4):23-26
Q&P钢是一种高强度高塑性的第三代先进高强度钢种,合理的微观组织结构和塑性变形过程中引发的相变诱导塑性,是决定其力学性能的关键因素。通过SEM观察确定QP980的微观组织为板条马氏体、铁素体和残余奥氏体的混合组织。由XRD实验测量得到QP980钢板在单向拉伸状态下不同应变量对其残余奥氏体转化量的影响规律,发现QP980中残余奥氏体的体积分数随应变量的增加呈非线性下降的趋势。根据O-C马氏体相变动力学模型,得出QP980中残余奥氏体含量和等效应变的关系函数。根据等功原理和混合硬化准则,建立了考虑TRIP效应的QP980多相本构模型,并与QP980单向拉伸实验得到的应力应变曲线对比,验证了该模型的有效性。 相似文献
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一、前言近年来人们对残余奥氏体有了进一步的认识,认为钢中残余奥氏体不再只是一种有害组织,残余奥氏体的存在及数量的改变会使钢的很多工艺性质和操作性质发生变化。如钻头、拉刀等长杆形高速钢刀具在热处理过程中所产生的不同程度变形的校直,就是利用了奥氏体硬度较低,塑性极好的特性。 相似文献
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Zhongping He Yanlin He Yuntao Ling Qihao Wu Yi Gao Lin Li 《Journal of Materials Processing Technology》2012,212(10):2141-2147
Tensile deformation behavior of Si–Mn TRIP (TRansformation Induced Plasticity) steel with vanadium and without vanadium and the DP (Dual Phase) steel of the same composition were studied in a large range of strain rate (0.001–2000 s?1) by routine material testing machine, rotation disk bar–bar tensile impact apparatus and high-speed material testing machine of servo-hydraulic type. In situ measurement of the transformation of retained austenite was performed by means of X-ray stress apparatus in order to have detailed knowledge about the transformation of retained austenite at quasi-static tensile. Microstructure of steels before and after tensile were observed by means of optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). It is shown that there is no yield plateau observed on the stress–strain curve at quasi-static condition for TRIP steel containing vanadium because the vanadium carbide suppress the formation of Cottrell atmosphere in matrix. Retained austenite of Si–Mn TRIP steel containing vanadium transforms to martensite at loading stress of 502 MPa (its yielding strength is 486 MPa), while the transformation of retained austenite in matrix of Si–Mn TRIP steel without vanadium happens when its yielding process is finished at quasi-static tensile. It is confirmed that phase transformation of retained austenite in TRIP steel is strain induced phase transformation. It is noted that tensile elongation of TRIP steel at dynamic tensile is always lower than that at quasi-static tensile. That is because gradually strain induced phase transformation of retained austenite in TRIP steel is suppressed by deformation localization at dynamic tensile. 相似文献
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渗碳后热处理制度对接触疲劳性能的影响 总被引:2,自引:0,他引:2
考察了渗碳后几种不同热处理试样的组织与其接触疲劳性能的关系,结果表明,渗碳后缓冷组织状态的试样,再加热淬火处理后,其接触疲劳性能优于渗碳后油冷组织状态的试样,心部组织中存在铁素体将使试样的接触疲劳抗力下降;表层组织中残余奥氏体的量较多(〉35%)时,其转变对提高接触疲劳抗力起主导作用,残余奥氏体的量较少(〈25%)时,组织细化对提高接触疲劳抗力起主导作用。 相似文献
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Chang Gil Lee Sung-Joon Kim Byung-Hwan Song Sunghak Lee 《Metals and Materials International》2002,8(5):435-441
The effects of volume fraction and the stability of retained austenite on the formability of a 0.15C−1.5Si−1.5Mn (hereafter
all in wt.%) TRIP-aided multiphase cold-rolled steel sheet were investigated after various heat treatments. The steel sheets
were intercritically annealed at 800°C, and isothermally treated at 400°C and 430°C. Microstructural observation, tensile
tests and limiting dome height (LDH) tests were conducted on the heat-treated sheet specimens, and the changes in retained
austenite volume fraction as a function of tensile strain were measured using an X-ray diffractometer. The results showed
a plausible relationship between formability and retained austenite stability. Although the same amount of retained austenite
was obtained after isothermal holding at different temperatures, better formability was obtained in the specimens with the
higher stability of retained austenite. If the stability of the retained austenite is high, the strain-induced transformation
of retained austenite to martensite can be stably progressed, resulting in a delay of necking to the high strain region and
improvement in formability. 相似文献
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Tensile behavior of TRIP-aided multi-phase steels studied by in situ neutron diffraction 总被引:2,自引:0,他引:2
Y. Tomota H. Tokuda Y. Adachi M. Wakita N. Minakawa A. Moriai Y. Morii 《Acta Materialia》2004,52(20):5737-5745
TRIP-aided multi-phase steels were made by thermo-mechanically controlled process, where the ferrite grain size and the amount of the retained austenite were changed by controlling process conditions. The tensile behavior of four steels was studied by in situ neutron diffraction. It is found that the retained austenite bearing about 1.0 wt% C is plastically harder than the ferrite matrix. The steel with a ferrite grain size of ≈2.0 μm showed tensile strength of 1.1 GPa and a uniform elongation of 18.4%, in which stress-induced martensitic transformation occurs during plastic deformation but a considerable amount of austenite remains even after the onset of necking. It is concluded that the enhancement of uniform elongation is caused mainly by the work-hardening due to the hard austenite and martensite, where the contribution of the transformation strain is negligible. 相似文献
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EFFECTS OF TEST TEMPERATURE AND STRAIN RATE ON THE MECHANICAL PROPERTIES IN AN INTERCRITICALLY HEAT-TREATED BAINITE-TRANSFORMED STEEL 总被引:1,自引:0,他引:1
Z. Li ) D. Wu)) The State Key Laboratory of Rolling Automation Northeastern University Shenyang China) Institute of Aeronautical Engineering Shenyang China 《金属学报(英文版)》2004,17(6):840-848
1.IntroductionThe demand for high strength steels with excellent ductility has increased in the automotive indus-try in order to improve manufacturing and safety and to reduce weight. High strength transforma-tion-induced plasticity (TRIP) steel sheets have received increased attention, as they have both high strength and ductility due to the martensitic transformation of retained austenite during plastic defor-mation.Transformation-induced plasticity was the phenomenon first found in steel … 相似文献
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I. D. Choi D. M. Kim S. J. Kim D. M. Bruce D. K. Matlock J. G. Speer 《Metals and Materials International》2006,12(1):13-19
The safety of passengers is important during an automobile collision. Because a collision event involves high speed deformation,
it is necessary to develop property data and understand the applicable deformation mechanisms to aid in the selection of proper
materials for crash-related automotive components. Therefore, dynamic mechanical properties of low carbon TRIP steels with
varying retained austenite stabilities were evaluated over a wide range of strain rates using a high-velocity hydraulic tensile
testing machine. Tensile tests were performed at strain rates ranging from 102 to 6×102 s1 using standard ASTM E-8 specimens with an elastic strain gage attached to the sample grip end to measure load, and a plastic
strain gage mounted onto the gage section to measure strain. Ultimate tensile strengths (UTS), strain rate sensitivities,
and strain hardening behaviors are reported. TRIP steel with high stability retained austenite exhibited higher yield stress,
lower UTS and lower strain hardening than TRIP steel with low stability retained austenite. 相似文献
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高速冲击拉伸条件下低硅TRIP钢的延伸率特性 总被引:3,自引:0,他引:3
对低硅HSLA -TRIP钢在室温条件下 5 0 0s-1~ 1 70 0S-1应变率范围内的动态拉伸性能进行了研究。实验结果表明 ,随应变率增大 ,钢的均匀延伸率 (eu)下降、总延伸率(et)和能量吸收值增加 ,但强度 (σb)保持不变或略有提高 ,能量吸收的增幅随应变率增大而变缓。分析认为 :残余奥氏体在颈缩发生前的较完全转变有利于提高均匀延伸率 ;高应变率下能量吸收值的提高可能由两个原因造成 :一是大应变下的奥氏体相变推迟断裂的发生 ;二是动态拉伸中的绝热温升有利于总延伸率的提高。 相似文献