基于热拉伸试验的DP590高强钢变形本构关系及热加工图

发布时间：2018-05-05 19:52

本文选题：DP高强钢 + 热成形　；参考：《锻压技术》2017年01期

【摘要】：在变形温度为1123~1423 K和应变速率为0.01~10 s-1条件下,对DP590高强钢进行高温热拉伸试验,得到其真应力-真应变曲线,分析了温度和应变速率对DP590高强钢热变形时流动应力的影响。结果表明,当应变量一定时,流动应力随应变速率的升高和温度的降低而增大。基于热拉伸试验数据,通过线性回归分别确定了在峰值应力下DP590高强钢的高温材料常数:应变硬化指数n=3.194,热变形激活能Q=508.29 k J·mol-1,α=0.0153和A=2.126×1017s-1。构建了DP590高强钢的Arrhenius双曲正弦本构关系,与试验值相比,模型的最大误差为7.8%,最小误差为0.18%。根据DMM动态材料模型建立了DP590高强钢在应变为0.3条件下的热加工图,确定了DP590高强钢的适宜热成形区为:应变速率为0.01~0.1 s-1,变形温度为1250~1375 K。
[Abstract]:The true stress-true strain curves of DP590 high strength steel were obtained by high temperature thermal tensile test under the condition of deformation temperature of 1123 ~ 1423K and strain rate of 0.01g / 10s ~ (-1). The effects of temperature and strain rate on the flow stress during hot deformation of DP590 high strength steel were analyzed. The results show that the flow stress increases with the increase of strain rate and the decrease of temperature when the strain variable is constant. Based on the thermal tensile test data, the high temperature material constants of DP590 high strength steel under peak stress were determined by linear regression: strain hardening exponent nn = 3.194, hot deformation activation energy Q = 508.29kJ mol-1, 伪 = 0.0153 and A = 2.126 脳 1017s-1, respectively. The Arrhenius hyperbolic sinusoidal constitutive relation of DP590 high strength steel is constructed. Compared with the experimental data, the maximum error of the model is 7.8 and the minimum error is 0.18. According to the DMM dynamic material model, the hot working diagram of DP590 high strength steel under the condition of strain is 0. 3. The suitable hot forming zone of DP590 high strength steel is determined as follows: strain rate is 0. 01 ~ 0. 1 s ~ (-1) and deformation temperature is 1 250 ~ 1 375 K.
【作者单位】：重庆科创职业学院汽车工程学院;重庆电子工程职业学院汽车工程学院;
【基金】：重庆市教委2015年度科学技术研究项目(KJ1505301)
【分类号】：TG142.1

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