一种改进的金属材料的高温动态拉伸实验技术

在旋转盘冲击拉伸实验装置上,利用金属材料自身的导电特性,对试样施加电流.使其在电流作用下发热,实现自加热,形成了试件快速加热而波导杆温升很小的金属材料的动态高温高应变率拉伸实验技术.应用该实验技术获取了45 #钢从室温到1000℃温度范围和应变率650s-1时的材料动态拉伸应力—应变曲线.实验结果表明,45 #钢具有明显的热软化效应,其流动应力和屈服应力随温度的升高而降低.

An Improved High Temperature Dynamical Tensile Experimental Technique for Metal Materials

Current was applied to metal specimen and made it heating due to its conductivity.Thus,based on a rotating disk tensile impact apparatus,a high temperature dynamical tensile experimental technique was developed.Using this technique,specimen can be heated quickly,but the wave bars temperature increases slowly.So dynamic high temperature and high strain-rate tensile experiment can be performed.Dynamic tensile stress-strain curve of 45# steel was obtained based on this improved technique with the temperature range from room temperature to 1000℃ and the strain rate 650s-1.Experimental results show that 45# steel has an obvious thermal softening effect and its flow stress and yield stress decrease with temperature increase.