变形条件对C-Mn钢力学性能的影响机理

Influence Mechanism of Deformation Conditions on Mechanical Properties of C-Mn Steel

借助Gleeble 3500热模拟试验机和Instron 8801试验机对一种C-Mn试验钢进行了高温和室温拉伸试验,测量和计算了试验钢的力学性能,观察了断口形貌和显微组织,分析其力学性能随拉伸温度和应变速率变化的规律及机理。结果表明:随拉伸温度的升高和应变速率的减小,试验钢的屈服强度和抗拉强度逐渐降低,屈强比呈上升趋势;而断面收缩率在720℃出现极小值,随应变速率的增加逐渐增大。温度和应力作用引发的杂质原子的非平衡晶界偏聚影响着试验钢的塑性。

A kind of C-Mn tested steel was tested at high temperature and room temperature by the Gleeble 3500 thermal simulation testing machine and the Instron 8801 testing machine.The mechanical properties of the tested steel were measured and calculated,the fracture morphology and microstructure were observed,and the change rule and mechanism of mechanical properties with tensile temperature and strain rate were analyzed.The results show that,with the increase of tensile temperature and the decrease of strain rate,the yield strength and tensile strength of the tested steel gradually decrease,and the yield ratio has an upward trend.The reduction of area appears a minimum at 720℃,and it increases with the increase of strain rate.The non-equilibrium grain boundary segregation of impurity atoms caused by temperature and stress affects the plasticity of the tested steel.