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为提高相变诱发塑性(TRIP)钢的有限元数值模拟计算精度,在板材两步拉伸实验的基础上,建立了一种Voce和Hollomon组合的TRIP钢V/H硬化模型。两步拉伸实验结果显示,当两次拉伸方向的夹角增大时,TRIP钢表现出交叉硬化现象,且随着夹角的增大,其硬化率和断裂伸长率均出现下降。根据上述实验观察,H/V模型引入了以应变路径夹角为自变量的Voce和Hollomon项线性权重系数。随着角度的增大,令Hollomon项权重下降而Voce项权重上升,以此来体现应变路径变化对其硬化行为的影响。为检验所提出的组合硬化模型在大应变范围内对TRIP钢硬化行为的预测能力,建立了两步拉伸的有限元数值模拟模型,并与实验结果进行了对比。相比普通的Voce和Hollomon模型,该组合模型能够更好地重现TRIP钢在应变路径变化后的硬化行为,且具有更高的断裂伸长率计算精度。 相似文献
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将已经趋于成熟的TRIP钢生产技术应用到钢管的生产领域,成功开发出具有铁素体、贝氏体、残余奥氏体和少量马氏体组织的薄壁TRIP钢无缝钢管,并利用普通拉伸、管端扩口、环形拉伸以及液压自由膨胀等试验手段对其力学性能及内高压成形性能进行了试验研究。研究结果表明,TRIP钢无缝钢管具有较好的轴向、周向力学性能及内高压成形性能,可以在内高压成形领域中推广应用。 相似文献
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热轧TRIP钢具有优异的力学性能,热轧生产后经过酸洗处理可以直接用于汽车制造。采用Gleeble3500型热模拟试验机研究了C-Si-Mn-Nb系热轧TRIP钢形变奥氏体在不同连续冷却条件下的组织变化情况,绘制了动态CCT曲线。通过研究不同冷速下试样组织发现,冷却速率越大,组织中未转变奥氏体含量越低。最后,依据对动态CCT曲线的分析在Gleeble3500型热模拟试验机上模拟热轧了TRIP钢。结果表明:实验钢轧后以15℃/s的低冷却速率冷却至贝氏体区等温后,残留奥氏体的含量和稳定性更高,TRIP钢力学性能优异,抗拉强度和伸长率分别达到952 MPa和30%,强塑积高达28560 MPa·%。 相似文献
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汽车用先进高强钢的成形性能 总被引:1,自引:0,他引:1
通过试验,对汽车用先进高强钢DP590、DP780、TRIP590的力学性能、微观金相组织、成形极限图进行研究,并与超深冲钢DC01成形极限进行对比。运用成形极限预测近似公式,对DP590、DP780、TRIP590、DC01的成形极限曲线进行预测,并与实测曲线进行对比。结果表明,DP钢和TRIP钢都具有较高的强度和良好的塑性,并具有较低的屈强比,能有效避免成形时局部颈缩和断裂。同时,DP钢和TRIP钢均具有良好的成形性能,DP590、TRIP590的成形能力甚至优于超深冲钢DC01。成形极限预测经验近似公式能很好的适用于DP590、DP780、TRIP590的成形极限预测,误差在2%以内,但对于DC01的成形极限预测误差则稍微偏大,约为4%。 相似文献
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利用万能试验机、液压伺服高速拉伸试验机和霍普金森杆3种设备,开展了HC340LA低合金高强钢多个应变速率的拉伸试验,得到了不同应变速率下的应力-应变曲线,研究了其动态力学性能。对高速拉伸试验数据进行二次开发,采用SwiftHockett-Sherby本构模型进行拟合外推,建立了HC340LA低合金高强钢的材料模型,并进行了纵梁部件落锤试验过程的数值模拟,数值模拟结果与落锤试验结果基本一致,验证了所建立的材料模型的准确性。同时,对比分析了液压伺服高速拉伸试验机和霍普金森杆设备的高速拉伸试验结果。结果表明:液压伺服高速拉伸试验机测量得到的中低应变速率动态曲线与材料准静态曲线有更好的对应关系;霍普金森杆设备适合更高应变速率的试验,无法精准获取材料的真实变形,只能准确测得材料的抗拉强度。 相似文献
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Due to worldwide environmental concerns, automobile industries are trying to reduce the weight of the vehicles without compromising
the crashworthiness by employing high-strength steel sheets as much as possible. Transformation-induced plasticity (TRIP)
steels, relatively newer in the structural application, might play an important role in this regard. In this present work,
tensile and plane bending fatigue properties and fracture behaviors of two low-alloy TRIP (TRIP590 and TRIP780 grades) steels
were investigated at room temperature in air. After mechanical tests, fractographic observations were carried out in the SEM.
Both steels showed reasonably high values of elongations and fatigue limits. However, with an increase in the bending stress
level, the fatigue performance of TRIP780 steel improved gradually. 相似文献
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在试验室模拟薄板坯连铸连轧工艺生产了含Mo、Nb的TRIP钢.拉伸试验检测表明,试验钢的力学性能为σb =915 MPa,σs=780 MPa,δ=16%;试样组织为铁素体+贝氏体+残留奥氏体,X射线衍射分析表明残留奥氏体的含量为5%;透射电镜观察发现,晶内有大量纳米尺度的(Nb,Ti)C,MnS 和(Nb,Ti)C粒子复合析出,残留奥氏体为薄膜状. 相似文献
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通过大试样拉伸与小试样拉伸相结合的方法,分析冷轧TRIP780钢的瞬时应变硬化速率随应变水平的变化规律,详细讨论不同应变路径下TRIP钢应力应变曲线体现出的硬化特性,并对微观组织的演变进行扫描电镜观察。结果表明,TRIP钢不仅具有较高的初始硬化能力,而且具有较长应变范围内的后续硬化能力;非比例加载路径下TRIP钢应力应变曲线表现出了软化效应、瞬时硬化能力和相交效应;加载路径的改变,可引起位错的运动方向和稳定性发生改变,从而影响硬化行为。 相似文献
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文章研究了一种基于摆锤式仪器化冲击试验机所开发的,针对汽车用钢板实施中等应变速率冲击拉伸加载的试验方法,并以此获得了DC04、DC56、H220、TRIP700和DP780的动态响应特性与加载应力-应变关系。研究表明,以铁素体软钢为典型的速率敏感材料,随着其应变速率的提高,材料强度增加,而塑性受到抑制。TRIP钢的性能与加载速率无明显相关特性,其力学性能在静态与动态条件下相对稳定。DP780钢的强度与塑性在动态加载条件下得到同步提升。此外,通过将冲击拉伸破断能转化为应力与应变的积分,试验获得的E10%与Euniform及Et能量指标,可定量分析汽车用钢碰撞时变形与吸能的相关特性,成为评价车用钢减重与安全的纽带。试验表明,随着材料强度级别的提升,其动态吸能特性得以成比例升高。同时,由E10%与Euniform指标构成的能量安全裕度,揭示出TRIP钢具有最为优异的动态变形吸能潜质。 相似文献
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针对起重机的钢梁结构的疲劳问题,选取起重机所用钢材制得3组试样进行测试,每组试样的中间标距部分标记了3个位置,随后对试样进行拉伸试验,拉伸前后分别进行矫顽力测试,对拉伸试验过程进行仿真工作,将得到的仿真应力云图与矫顽力云图进行了对比。测试及仿真结果表明:随着外加拉应力的增大,材料的矫顽力(Hc)逐渐增大,矫顽力呈现阶段性的变化规律,这可能与残余应力在材料内部产生位错的钉扎效应有关,矫顽力云图表明试样内部的晶体结构受到不同程度的破坏,矫顽力也随之增加。进一步对矫顽力与应变数据进行理论分析,得到矫顽力 应变拟合曲线与拟合方程。 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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Effects of pre-strain and bake-hardening on the crash properties of a top-hat section 总被引:1,自引:0,他引:1
L. Durrenberger X. Lemoine A. Molinari 《Journal of Materials Processing Technology》2011,211(12):1937-1947
The effects of pre-strain on the crushing properties of a crash-box structure are reported for two Advanced High Strength Steels produced by ArcelorMittal (Dual-Phase DP600 and Transformation Induced by Plasticity TRIP780 steels). In addition, the effect of a bake-hardening treatment is studied on the TRIP780 steel. The material's behaviors have been determined in tensile loading in a wide range of strain-rates () including strain-rate jump tests from quasi-static to dynamic loading. These interrupted tests allow us to characterize the effect of the (quasi-static) forming process on the subsequent dynamic behavior associated to the crash event. A phenomenological visco-plastic model, based on the evolution of an internal variable, has been implemented in PAMCRASH using a user-defined subroutine in order to simulate the crushing of the crash-boxes. A simple approach is proposed to account for the bake-hardening treatment in numerical simulations. A good correlation between experimental and predicted mean crush forces is obtained. 相似文献
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研究拉伸试验温度对TRIP钢力学性能的影响规律,对于板带温加工成型的工艺参数探索有重要的参考价值。将A、B两种TRIP钢经过热轧后在盐浴炉中分别保温3 min和5 min,然后在50~350℃进行拉伸试验研究,对比其力学性能变化。结果表明,A、B试样在200℃和250℃拉伸时,抗拉强度因TRIP效应而达峰值,分别达到895 MPa和881 MPa;而伸长率降低不明显,在100℃时,伸长率达到36%和38%。300℃和350℃时,不再发生应变诱导马氏体相变,故抗拉强度、伸长率均降低。B试样因其残余奥氏体更加稳定而具有更显著的TRIP效应,其力学性能优于A试样。 相似文献
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X.C. Wei L. Li R.Y. Fu W. ShiSchool of Materials Science Engineering Shanghai University Shanghai China Manuscript received June in revised form November 《金属学报(英文版)》2002,15(3):285-294
二.互ntYO*llCtloliAs kn OWOWn,the beh yyiors of the strength and ductility of material under dynamic con-dltlon are obviously differs尬from those under static condition.几ensure the reft劝ility ofstructure under dynamic or impact loading It Is necessar 相似文献