不同应变速率下1800MPa级热成形钢力学性能研究

Research of 1800 MPa Grade PHS Mechanical Properties Under Different Strain Rate

针对1800MPa级热冲压成形用钢,采用Zwick HTM 5020型高速拉伸试验机对1800MPa级热成形钢进行高速拉伸实验,应变速率分别为0.001 s-1、0.1 s-1、1 s-1、10 s-1、100 s-1、1000 s-1,得到相应的强度和延伸率数据,并对强度和延伸率变化规律进行了分析。结果表明:在应变速率为10-3 s-1-1 s-1时,强度的应变速率敏感性较低;在应变速率为101 s-1-103 s-1时,强度的应变速率敏感性较高。另外,本实验钢在较低应变速率下(10-3 s-1-1 s-1),延伸率的应变速率敏感性很高,延伸率增速的转折点为0.1 s-1;应变速率≥0.1 s-1时,实验钢断后延伸率>11%。

High-speed tensile experiment was carried on 1800 MPa grade press hardening steel under different strain rate,respectively 0.001 s-1,0.1 s-1,1 s-1,10 s-1,100 s-1,and 1000 s-1 by Zwick HTM 5020 type high-speed tensile testing machine.The intensity and elongation were got and the corresponding variation law were analyzed.Results show that at strain rate range(10-3-1 s-1)intensity is less sensitive with strain rate increase.While at strain rate(101-103 s-1)intensity is more sensitive.In addition,this experiment steel under low strain rate(10-3-1 s-1),elongation is more sensitive with strain rate increase,the turning strain rate point of elongation increase fast was 0.1 s-1.When the strain rate≥0.1 s-1,experiment steel elongation>11%.