430不锈钢热变形行为及高温起裂条件  

Hot deformation behavior and high temperature crack initiation conditions of 430 stainless steel

作　　者：孙建新 刘永胜[2] 郭宝峰[1] 金淼[1] 陈雷[1] 薛红燕 SUN Jian-xin;LIU Yong-sheng;GUO Bao-feng;JIN Miao;CHEN Lei;XUE Hong-yan(School of Mechanical Engineering,Yanshan University,Qinhuangdao 066004,China;Confederation of Chinese Metalforming Industry,Beijing 102206,China;Beijing Research Institute of Mechanical&Electrical Technology Co.Ltd.,Beijing 100083,China)

机构地区：[1]燕山大学机械工程学院,河北秦皇岛066004 [2]中国锻压协会,北京102206 [3]北京机电研究所有限公司,北京100083

出　　处：《塑性工程学报》2022年第5期125-133,共9页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(52075474);河北省自然科学基金资助项目(E2019203560)。

摘　　要：通过单道次压缩热模拟试验,研究了大型海工阀体锻件用430不锈钢在变形温度1050~1250℃,应变速率为0.005~0.5 s^(-1)下的热变形行为,获得其真实应力-应变曲线。并通过回归计算,获得430不锈钢热变形过程中峰值应力的预测模型和峰值应变预测模型,确定了其再结晶热激活能约为469.82 kJ·mol^(-1),建立了特定应变下的热加工图,结合动态再结晶晶粒组织演化规律,明确了获得细小均匀组织的热加工参数范围,进而提出430不锈钢的合理锻造工艺窗口。依据测试结果,基于有限元计算,获得430不锈钢热变形中裂纹尖端临界状态下最大张开位移与临界扩张比参数之间的关系,进而求得1050~1150℃下裂纹尖端张开位移。Through single thermo simiulation compression experiment,the hot deformation behavior of 430 stainless steel for large marine vavle foegings was studied at 1050-1250℃with the strain rate of 0.005-0.5 s^(-1),and the true stress-strain curve was obtained.The prediction model of the peak stress prediction model and the peak strain prediction model of 430 stainless steel during hot deformation were obtained by regression calculation.The thermal activation energy of DRX is determined as 469.82 kJ·mol^(-1).The processing map at the certain strain was established.Combined with the evolution law of DRX grain structure,the reasonbale range of hot working parameters for achieving fine and uniform microstructurewas determined,and the reasonable forging process window of 430 stainless steel was proposed.Based on the experimental results,the relationship between the maximum crack tip-opening displacement and the critical expansion ratio at the critical state was obtained based on the finite element calculation,and the maximum crack tip-opening displacement at 1050-1150℃was clarified.

关 键 词：430不锈钢 热变形行为 变形抗力模型 热加工图 裂纹尖端张开位移 

分 类 号：TG316[金属学及工艺—金属压力加工]