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应用ProcessingMap研究D2钢高温变形的动态应变时效 总被引:2,自引:0,他引:2
应用以动态材料模型为基础的ProcessingMap研究了D2钢在变形温度900~1160℃、变形速率0.01~10.00s-1区间的动态应变时效规律。结果表明,D2钢在变形温度为1120~1150℃、变形速率为0.01s-1条件下发生动态应变时效,并表现出强烈的硬化效应。同时,应变速率敏感系数小于零可以作为发生动态应变时效的一个标志。 相似文献
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中碳钢形变及冷却过程中的组织演变 总被引:1,自引:0,他引:1
热模拟单向压缩下,中碳钢形变温度低于Ad3(786℃)点时,析出形变诱导铁素体(DIF),DIF量随形变温度降低而提高;在低于750℃形变时,DIF量远高于平衡态铁素体含量54%。DIF析出时碳原子高度富集在铁素体晶界和铁素体/奥氏体界面。形变后在低于A1(719℃)温度等温或控冷过程中。过冷奥氏体将发生不同类型的转变:高于Ad3形变试样中,奥氏体转变为铁素体+片层状珠光体;低于Ad3点但高于Ar3(645℃)点形变时,未转变奥氏体转变为铁素体+片层状珠光体+晶界渗碳体;稍高于Ar3点形变时,将获得铁素体+弥散渗碳体的球化组织。 相似文献
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The 34CrMo4(AISI 4130)steel is extensively utilized in the compressed natural gas cylinders.Due to the importance of thermomechanical processing in the production of these cylinders,the dynamic recrystallization(DRX)characteristics of 34CrMo4 steel were investigated.The effect of hot deformation parameters such as temperature and strain rate on the dynamic restoration processes of a 34CrMo4 alloy was studied.Hot compression tests were performed in the temperature range of 900 to 1100 ℃ and the strain rate r... 相似文献
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The hot deformation behavior of S31042 austenitic heat-resistant steel was investigated over the tempera- ture range of 900--1 200 ℃ and strain rate range of 0.01--10 s- 1 using hot compression tests a... 相似文献
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In this investigation, hot compression tests were performed at 900 °C ? 1100 °C and strain rate of 0.001 ? 0.1 s?1 to study hot deformation behavior and flow stress model of 4130 steel. Based on the classical stress–dislocation relations and the kinematics of the dynamic recrystallization, the flow stress constitutive equations of the work hardening‐dynamical recovery period and dynamical recrystallization period were established for 4130 steel, respectively. The validity of the model was demonstrated by comparing the experimental data with the numerical results. The agreement of this comparison is quite reasonable. 相似文献
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Hot compression deformation behaviors of medium carbon Cr-Ni-Mo-Nb steel were investigated at deformation temperatures ranging from 1223 to 1423 Kand strain rates of 0.1,1and 5s-1.Dynamic recovery(DRV)and dynamic recrystallization(DRX)were observed during the hot compression deformation.For all of the samples,DRX occurred at deformation temperatures above 1323 Kat different strain rates,while below 1223 K,no DRX was observed.The activation energy of the tested steel was determined as 386.06kJ/mol.The ratio of critical stress to peak stress and the ratio of critical strain to peak strain were 0.835 and 0.37,respectively.Kinetic equations interpreting the DRX behavior of the tested steel were proposed,and the corresponding parameters including the volume fraction and the average grain size were determined.Moreover,the microstructures induced under different deformation conditions were analyzed. 相似文献
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Hot deformation behavior of GCr15 (ASTM 52100) steel was investigated using single-hit compression tests on Gleeble-1500 simulator at the temperature range of 850-1100 ℃ and strain rate range of 0. 1-10 s-1. The flow stress constitutive equation of GCr15 steel during hot deformation was determined by stress-strain curves analysis on the basis of the hyperbolic sine equation. And the models of dynamic recrystallization fraction and dynamic recrystallization grain size of GCr15 steel were established by the measured curves and microstructure observation in different experimental conditions. The mean activation energy and the time exponent of dynamic recrystallization kinetics equation in the range of experimental conditions were determined to be 356. 2 kJ/mol and 2. 12, respectively. Meanwhile, the flow stress model was also established by the method of allocating flow stress curve with three main stress values, the saturation stress, the steady state stress and the stress when strain is 0. 1. The flow stress curves predicted by the developed models under different deformation conditions are in good agreements with the measured ones. 相似文献
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利用Gleeble-3800热模拟试验机对超低碳13Cr-5Ni-2Mo马氏体不锈钢进行单道次高温压缩试验,研究其在900~1 200 ℃、0.1~50 s-1条件下的热变形行为,并讨论了不同变形条件下的微观组织演变规律;基于Sellars双曲正弦模型构建了超低碳13Cr-5Ni-2Mo 马氏体不锈钢的高温流变应力本构方程。研究结果表明,变形温度越高、应变速率越低,则流变应力越小,峰值应变也越小,微观组织由动态回复型向动态再结晶型转变,并且晶粒逐渐长大、粗化。在高温区变形,随着应变速率的升高,动态再结晶晶粒明显细化。所建立的本构方程具有较高的精确度,能反映超低碳13Cr-5Ni-2Mo 马氏体不锈钢的高温变形力学行为,可为热加工数值模拟研究提供参考。 相似文献
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通过分析不同变形温度及应变速率下低硅含磷系TRIP钢高温流变曲线的变化规律,建立了本构关系,并分析了合金元素钒对其影响。结果表明,添加0.19%钒,由于固溶钒原子的拖曳作用,使动态再结晶激活能提高~6%,同时推迟了动态再结晶的发生,使σc/σp和εc/εp值均有所提高。通过回归得到无钒钢和含钒钢的峰值应力和临界应力、峰值应变和临界应变与lnZ的关系。 相似文献