Fe-28Mn-7Al-1.1C奥氏体钢的热变形行为  

Hot Deformation Behavior of Fe-28Mn-7Al-1.1C Austenitic Steel

作　　者：李悦 梁力文 王青峰[2] 高欣 LI Yue;LIANG Liwen;WANG Qingfeng;GAO Xin(Jiangyin Nangong Forging Co.,Ltd.,Jiangyin Jiangsu 214400,China;State Key Laboratory of Preparation Technology and Science of Metastable Materials,Yanshan University,Qinhuangdao Hebei 066004,China)

机构地区：[1]江阴南工锻造有限公司,江苏江阴214400 [2]燕山大学亚稳材料制备技术与科学国家重点实验室,河北秦皇岛066004

出　　处：《上海金属》2024年第6期1-10,共10页Shanghai Metals

基　　金：国家重点研发计划(2017YFB0304800,2017YFB0304802)。

摘　　要：采用Gleeble-3500热模拟试验机通过单道次热压缩试验,研究了Fe-28Mn-7Al-1.1C奥氏体钢在不同变形温度与应变速率条件下的热变形行为,建立了该钢的本构模型及热加工图。结果表明:在温度为900~1150℃、应变速率为0.01~5 s^(-1)的热变形条件下,试验钢的真应力-真应变曲线主要分为动态回复与动态再结晶两种;试验钢表现为正应变速率敏感性,其变形抗力随着应变速率的增大而增大,这主要是位错运动与再结晶时间两方面共同作用所致;同时由于变形温度的升高,动态回复与动态再结晶速度加快,材料晶格中原子动能增加,有利于位错运动和材料的流变应力减小,从而使钢表现出负温度敏感性。变形温度的升高与应变速率的降低均有利于促进试验钢的动态再结晶过程,1100℃变形时试验钢发生了完全动态再结晶;通过理论计算得出,Fe-28Mn-7Al-1.1C钢的热变形激活能为416.475 kJ/mol,并构建了应变速率-变形温度-变形抗力的本构方程及热加工图,获得适合该钢的热加工变形条件为:变形温度1100~1150℃,应变速率为0.1~1 s^(-1);变形温度1050~1100℃,应变速率小于0.1 s^(-1);变形温度900~1025℃,应变速率为0.01~0.1 s^(-1)。Hot deformation behavior of Fe-28Mn-7Al-1.1C austenitic steel under different deformation temperatures and strain rates was studied through single-pass hot compression test by using Gleeble-3500 thermal simulator,and a constitutive model and hot processing map of the steel were established.The results showed that(a)under the hot deformation conditions of temperature of 900 to 1150℃and strain rate of 0.01 to 5 s^(-1),the true stress-true strain curve of the tested steel was mainly classified into two types:dynamic recovery and dynamic recrystallization;(b)the tested steel exhibited positive sensitivity to strain rate,and its deformation resistance increased with the increase of strain rate,mainly due to the combined effect of dislocation movement and recrystallization time,simultaneously,due to the increase in deformation temperature,the dynamic recovery and dynamic recrystallization were accelerated,and the atomic kinetic energy in the lattice of the material increased,which was conducive to movement of dislocation and to decrease in the flow stress of the material,resulting in that the steel showed negative sensitivity to temperature;(c)the increase in deformation temperature and the decrease in strain rate were both beneficial to promote the dynamic recrystallization process of the tested steel,and under the deformation temperature of 1100℃,the tested steel was completely recrystallized;and(d)according to theoretical calculations,the activation energy for hot deformation of Fe-28Mn-7Al-1.1C steel was 416.475 kJ/mol,and a constitutive equation that correlated strain rate,deformation temperature,and deformation resistance and hot processing map were established,the hot processing deformation conditions suitable for this steel were obtained as follows:deformation temperature ranging from 1100 to 1150℃and strain rate ranging from 0.1 to 1 s^(-1);deformation temperature ranging from 1050 to 1100℃and the strain rate was less than 0.1 s^(-1);deformation temperature ranging from 900 to 1025℃and the strain rat

关 键 词：奥氏体钢 热变形 变形温度 应变速率 本构方程 

分 类 号：TG142.3[一般工业技术—材料科学与工程]