S32205双相不锈钢冷轧退火组织转变及强塑化机理分析  

Microstructure transformation and strengthening-plasticization mechanism of S32205 duplex stainless steel after cold rolling and annealing

作　　者：吕杰晟 宋志刚[1] 何建国 丰涵[1] 郑文杰[1] 朱玉亮[1] LüJiesheng;Song Zhigang;He Jianguo;Feng Han;Zheng Wenjie;Zhu Yuliang(Research Institute of Special Steels,Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China)

机构地区：[1]钢铁研究总院有限公司特殊钢研究院,北京100081

出　　处：《金属热处理》2022年第4期141-145,共5页Heat Treatment of Metals

摘　　要：通过设计一种特殊的冷变形退火工艺,实现了S32205双相不锈钢强度和塑性同时提升。通过室温拉伸试验、显微组织观察、背散射电子衍射分析、热力学计算等手段研究了显微组织特征及新组织结构的强塑化机理。结果表明,该工艺处理后S32205双相不锈钢的晶粒尺寸呈双态分布,两相组织混合分布且细晶的新生奥氏体均匀弥散分布在铁素体相中;在细晶强化和两相间变形不协调引发的背应力强化的共同作用下,试验钢强度和塑性相较于传统固溶热处理工艺同时得到了提升。A novel process of cold rolling and annealing was designed to improve mechanical properties of S32205 duplex stainless steel.Both the tensile strength and the elongation were enhanced by this process.The microstructure characteristics and the strengthening mechanism of the new-designed microstructure were investigated by means of room temperature tensile tests,optical microscope,electron back-scattered diffraction analysis and thermodynamic calculations,etc.The results show that the microstructure of the S32205 duplex stainless steel obtained by the process exhibits a bimodal grain size distribution with fine austenite precipitated in the ferrite phase.Under the combined effect of fine-grained strengthening and back stress strengthening caused by the incompatible deformation between the two phases,the strength and plasticity of the tested steel are both improved compared with the conventional solution heat treatment process.

关 键 词：双相不锈钢 组织调控 细晶强化 背应力强化 力学性能 

分 类 号：TG156[金属学及工艺—热处理]