摘要
在Gleeble-1500D热模拟试验机上对19MnB4冷镦钢进行了常温压缩变形试验,应变速率设置为0.01、0.1、1 s^(-1)。研究了19MnB4在常温下塑性变形的流变应力,并分析了应变和应变速率对其的影响机制。结果表明:19MnB4钢具有明显的应变速率敏感性,常温压缩下的屈服强度随着应变速率的增大明显提高。根据实验数据,利用最小二乘法原理拟合得到冷镦钢19MnB4的Johnson-Cook塑性变形本构方程。计算结果和试验结果对比表明,该方程能较好地表达材料在常温下不同应变速率压缩的流变应力变化趋势。
The compression deformation test of 19MnB4 cold heading steel was carried out on Gleeble-1500D thermal simulation machine at room temperature. The strain rate was set to 0.01, 0.1 and 1 s^-1. The flow stress of plastic deformation of 19MnB4 at room temperature was studied, and the influencing mechanism of strain and strain rate on it was analyzed. The results show that 19MnB4 steel has obvious strain rate sensitivity, and the yield strength increases obviously with the increase of strain rate at room temperature. According to the experimental data, the Johnson-Cook plastic deformation constitutive equation of cold heading steel 19MnB4 was gotten by using the least squares principle fitting. Calculation results and test results show that the equation can express the changing trend of the flow stress of the material at room temperature and different strain rates well.
出处
《热加工工艺》
CSCD
北大核心
2016年第13期142-145,共4页
Hot Working Technology
