摘要
使用Gleeble-3800热模拟试验机对锻造态AM355不锈钢进行等温热压缩试验,应变速率选择0.01~10 s^-1,变形温度选择1173~1423 K。热变形后的组织通过光学显微镜、电子背散射衍射、透射电镜进行观察。基于Arrhenius模型采用峰值应力构建了本构方程,并对其改进得到了准确度更高的本构方程。采用动态材料模型构建了热加工图。由热加工图与变形后的组织得到了真应变为0.9时的热加工窗口。结果表明,适用于AM355钢的最优热加工区域为变形温度1250~1300 K、应变速率0.01~0.03 s^-1与变形温度1300~1400 K、应变速率0.01~10 s^-1及变形温度1400~1423 K、应变速率0.5~10 s^-1,该区域下能量耗散率均小于0.36,且发生了完全的动态再结晶。此外,还确立了完全动态再结晶时奥氏体晶粒尺寸ddrx与Z参数的关系。
The isothermal hot compression test of as-forged AM355 stainless steel was conducted by Gleeble-3800 thermo-mechanical simulator in the strain rates range between 0.01-10 s^-1 and the temperatures range between 1173-1423 K.And microstructure after hot deformation was observed by means of OM,EBSD and TEM.The constitutive equations based on Arrhenius model as well as a modified equation with higher accuracy were established by the peak stresses obtained from the stress-strain curves under various conditions.The hot processing maps were constructed based on dynamic materials model(DMM).The hot working window at a strain of 0.9 was determined on the basis of processing map and deformed microstructure.The results show that,the optimum domain for hot forming of AM355 steel is determined in the temperature and strain rate ranges between 1250-1300 K,0.01-0.03 s^-1 and 1300-1400 K,0.01-10 s^-1 as well as 1400-1423 K,0.5-10 s^-1 with the efficiency of endless than 0.36.It is found that the dynamic recrystallization(DRX)completed in this domain.Further,the relationship between austenite grain size of complete DRX(ddrx)and Zener-Holloman parameter(Z)is also given out.
作者
胡家齐
王长军
杨哲
梁剑雄
董瀚
Hu Jiaqi;Wang Changjun;Yang Zhe;Liang Jianxiong;Dong Han(Institute for Special Steel Institute,Central Iron and Steel Research Institute,Beijing 100081,China;College of Materials Science and Engineering,Chongqing University,Chongqing 401331,China;College of Materials Science and Engineering,Shanghai University,Shanghai 200072,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2020年第3期50-59,共10页
Heat Treatment of Metals
关键词
AM355钢
本构方程
热加工图
组织分析
AM355 steel
constitutive equation
processing map
microstructural analysis
