超级奥氏体不锈钢24Cr-22Ni-7Mo-0.4N的热变形行为及其组织演变  

Hot Deformation Behavior and Microstructue Evolution of Super Austenitic Stainless Steel 24Cr-22Ni-7Mo-0.4N

作　　者：赵政翔 廖露海 徐芳泓[2] 张威[2] 李静媛[1] ZHAO Zhengxiang;LIAO Luhai;XU Fanghong;ZHANG Wei;LI Jingyuan(Beijing Advanced Innovation Center for Materials Genome Engineering,School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory of Advanced Stainless Steel Materials,Taiyuan Iron and Steel(Group)Co.,Ltd.,Taiyuan 030003,China)

机构地区：[1]北京材料基因工程高精尖创新中心,北京科技大学材料科学与工程学院,北京100083 [2]太原钢铁(集团)有限公司先进不锈钢材料国家重点实验室,太原030003

出　　处：《材料研究学报》2023年第9期655-667,共13页Chinese Journal of Materials Research

基　　金：国家自然科学基金(U1806220);山西省科技重大专项(20191102006)。

摘　　要：对超级奥氏体不锈钢24Cr-22Ni-7Mo-0.4N进行单轴热压缩,研究了其在950℃~1200℃、应变速率为0.001 s^(-1)~10 s^(-1)的条件下的热变形行为;采用Arrhenius方程和Zener-Hollomon参数(Z)对变形参数建模并建立了本构方程,发现峰值应力、动态再结晶临界应力均与ln(Z/A)呈线性关系,材料的热变形激活能为497.11 kJ/mol。基于动态材料模型建立了不同塑性应变下的热加工图,使用电子背散射衍射技术(EBSD)表征了材料在不同变形条件下的微观组织,发现其在大多数变形条件下的软化机制是非连续动态再结晶(DDRX)。综合分析热加工图和微观组织,发现合理的热加工区域为变形温度1150~1200℃、应变速率0.1~1 s^(-1)。Hot deformation behavior and microstructure evolution of super austenitic stainless steel 24Cr-22Ni-7Mo-0.4N were studied by uniaxial compression tests at temperatures from 1123 K to 1473 K under strain rates of 0.001~10 s^(−1)up to the true strain of 0.8.The deformation parameters were modeled by Arrhenius equation and Zener-Hollomon parameter(Z).The peak stress and critical stress for dynamic recrystallization was found to exhibit a linear relationship with ln(Z/A),the thermal deformation activation energy of the steel was 497.11 kJ/mol.Based on the dynamic material model,the processing maps under different plastic strains were established.Electron backscatter diffraction(EBSD)was used to characterize the microstructure of the steel under different deformation conditions.The softening mechanism of the steel under most deformation conditions is discontinuous dynamic recrystallization(DDRX).Based on the analysis of microstructure and processing map,the optimum processing domain for hot deformation is identified as the deformation temperature of 1150~1200℃and strain rate of 0.1~1 s^(-1).

关 键 词：金属材料 超级奥氏体不锈钢 热变形 显微组织 加工图 动态再结晶 

分 类 号：TG142.1[一般工业技术—材料科学与工程]