摘要
利用Gleeble-1500D热力模拟试验机,对316LN钢进行变形温度为950℃～1200℃,应变速率为0.005s-1、0.05s-1、0.5s-1和1s-1的高温拉伸实验,得到不同变形条件下的真应力-真应变曲线;根据曲线做拉伸卸载实验,利用光学显微镜(OM)观察空洞萌生,确定空洞萌生应变。采用Normalized Cockcroft&Latham准则,用DEFORM 2D模拟高温拉伸变形过程,通过实验与数值模拟结果对比,得到了在不同变形条件下裂纹萌生的临界损伤值。该临界损伤值受温度和应变速率的影响,随着温度的降低而增加,随应变速率的增加而增加。该值的确定,对316LN钢锻造裂纹的预测及锻造工艺的制定具有指导意义。
The tensile tests of 316LN steel at high temperature were carried out on Gleeble-1500D thermal-mechanical simulator at temperature 950℃-1200℃ and strain rate 0. 005s ^-1, 0. 05s ^-1, 0.5s ^-1 and is ^-1. The true stress true strain curves of 316LN steel under different deformation conditions were obtained. The tensile-unload tests were carried out based on these curves. The void initiation was observed with optical mieroseope （OM） to determine void initiation strain. The tensile deformation process at high temperature was simulated with DEFORM 2D based on Normalized Cockcroft ＆ Latham criterion. The critical damage val ues of crack initiation under different deformation conditions were obtained based on the comparisons between experimental and numerical simulation results. These values depended on temperature and strain rate. The critical damage value of crack initiation increased with temperature decrease and strain rate increase. The determination of these values has guided significance for predic ting forging fracture and designing forging process of 316LN steel.
出处
《塑性工程学报》
CAS
CSCD
北大核心
2013年第3期60-64,共5页
Journal of Plasticity Engineering
基金
国家科技重大专项资助项目(2009ZX04014-062)
山西高校科技研究开发资助项目(20111015)
山西省研究生优秀创新资助项目(20103091)
关键词
316LN钢
高温拉伸
空洞萌生
临界损伤值
316LN steel
tension at high temperature
void initiation
critical damage value
