20CrMnTi淬硬钢的动态力学性能及其本构模型  

Dynamic Mechanical Properties and Constitutive Model of 20CrMnTi Hardened Steel

作　　者：盛精[1] 吕浩宇 向铁明[1] 王志敏 黄丛林[2] SHENG Jing;LYU Haoyu;XIANG Tieming;WANG Zhimin;HUANG Conglin(Fujian Key Laboratory of Advanced Design and Manufacture for Bus$coach,Xiamen University of Technology,Xiamen 361024,Fujian,China;Xiang Yang Factory,Dongfeng Peugeot Citroen Automobile Co.,Ltd.,Xiangyang 441004,Huibei,China)

机构地区：[1]厦门理工学院福建省客车先进设计与制造重点实验室,福建厦门361024 [2]神龙汽车有限公司襄阳工厂,湖北襄阳441004

出　　处：《机械科学与技术》2024年第12期2114-2122,共9页Mechanical Science and Technology for Aerospace Engineering

基　　金：福建省科技计划(2021H0027)。

摘　　要：为了厘清20CrMnTi淬硬钢在高温、高应变率下流动应力变化规律,采用了分离式Hopkinson压杆装置对试件在20℃、200℃、400℃、600℃和800℃条件下的动态力学行为开展了研究。分析了应变、应变率与温度对流动应力的作用规律,构建了材料的Johnson-Cook本构模型。实验结果表明:材料的应变硬化效应随着温度的上升逐渐减弱,且流动应力达到峰值对应的应变愈小;材料在20~600℃温度范围内,有动态应变时效现象发生;在800℃时材料对应变率表现出较强的敏感性;材料对温度的敏感性较强。通过将应变与温度软化项相关联,对J-C本构模型进行修正。修正后的模型能更为准确的描述20CrMnTi淬硬钢的动态力学行为。Aimed at the change in flow stress of 20CrMnTi hardened steel at high temperature and high strain rate,a separate Hopkinson pressure bar device was used to study the dynamic mechanical behavior of the specimen at 20,200,400,600 and 800℃.Effects of the strain,strain rate and temperature on the flow stress were analyzed,and the Johnson-Cook constitutive model of 20CrMnTi hardened steel was constructed.Experimental results show that the strain hardening effect of the material decreased with the increasing of temperature,and the strain range corresponding to the peak value of the flow stress become narrower;the material occurred dynamic strain aging in the temperature range 20-600℃,showed strong sensitivity to strain rate at 800℃,and it was found that the material was sensitive to temperature.The J-C constitutive model is modified by correlating the strain with the temperature softening term.The modified model can more accurately describe the dynamic mechanical behavior of 20CrMnTi hardened steel.

关 键 词：20CrMnTi淬硬钢 Johnson-Cook本构模型 应变率敏感性 温度敏感性 动态应变时效 

分 类 号：TG115.5[金属学及工艺—物理冶金]