铸造双相不锈钢时效过程组织演变  

Microstructure evolution of cast duplex stainless steel during aging

作　　者：曹静[1] 安立聪 杨弋涛[1,2] Cao Jing An Licong Yang Yitao(School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China Xinghua Institute of Special Stainless Steels, Shanghai University, Xinghua Jiangsu 225721, China)

机构地区：[1]上海大学材料科学与工程学院,上海200072 [2]上海大学兴化特种不锈钢研究院,江苏兴化225721

出　　处：《金属热处理》2016年第12期1-4,共4页Heat Treatment of Metals

摘　　要：借助光学显微镜(OM)、扫描电子显微镜(SEM)研究了铸造双相不锈钢在800℃时效不同时间的组织演变规律,并结合电子布氏硬度计(HBE-3000 A)研究时效过程组织转变对材料力学性能的影响。结果表明:时效过程中,双相不锈钢中铁素体相的比例随时效时间延长而逐渐减少,铁素体在时效处理过程中分解析出富Cr相和γ_2相,富Cr相主要存在铁素体与奥氏体的晶界处,而γ_2相则分布在铁素体基体上,并随着时效时间增加不断生成并长大。结合硬度测试结果发现,富Cr相的析出对材料硬度的提高起到了主要作用。Mierostructure evolution of duplex stainless cast steel aged at 800 ℃ for different time was investigated by means of OM and SEM, and influence of microstrueture on mechanical properties was also discussed based on HBE-3000 A hardness tester. The results show that with increasing of aging time, the proportion of ferrite phase decreases gradually. Ferrite phase decomposes into Cr-rich phase and ＂y2phase during aging. Cr-rich phase is mainly distributed at the grain boundary of ferrite and austenite, while ＂Y2 phase exists in the matrix of ferrite which generates and grows with aging time increasing. Combined with the results of hardness test, the presence of Cr-rich phase plays an important role in improving material hardness.

关 键 词：双相不锈钢 时效时间 组织 硬度 

分 类 号：TG156.92[金属学及工艺—热处理]