深冷处理后回火温度对15Cr超级马氏体不锈钢组织及耐点蚀性能的影响  

Effects of tempering temperature after cryogenic treatment on microstructure and pitting resistance of 15Cr super martensite stainless steel

作　　者：何潇 李俊[1] 李绍宏[1] 赵昆渝[1] 梁建雄 苏杰[2] He Xiao;Li Jun;Li Shaohong;Zhao Kunyu;Liang Jianxiong;Su Jie(Faculty of Material Science and Engineering,Kunming University of Science and Technology,Kunming Yunnan 650093,China;Institute for Special Steels,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]钢铁研究总院特殊钢研究所,北京100081

出　　处：《金属热处理》2020年第11期62-68,共7页Heat Treatment of Metals

基　　金：国家高技术研究发展计划(863计划)(201203A503)。

摘　　要：利用场发射扫描电镜、透射电镜以及电化学综合测试系统对15Cr超级马氏体不锈钢(SMSS)经不同热处理工艺处理后的显微组织变化和第二相碳化物及其对该钢腐蚀行为的影响进行了研究。结果表明,试验钢经不同热处理工艺处理后组织均由板条马氏体、奥氏体以及M(23)C6型碳化物颗粒组成,随着回火温度的增加,试验钢中逆变奥氏体含量增加,且在650℃回火时达到体积分数最大值41.41%。当回火温度高于600℃时第二相碳化物开始析出,且650℃回火后碳化物数量及尺寸较600℃增多。点蚀电位随着回火温度的增加而降低,第二相碳化物的析出降低了试验钢的点蚀电位,促进了亚稳点蚀位置的形成,从而降低了试验钢的耐腐蚀性能。Microstructure evolution and second phase carbides of 15 Cr super martensitic stainless steel(SMSS)treated by different heat treatment processes and their influence on the corrosion behavior were investigated by means of field emission scanning electron microscope(SEM),transmission electron microscope(TEM)and electrochemical comprehensive testing system.The results show that the microstructure of the tested steel are composed of martensite,austenite and M23 C6 carbides after different heat treatment processes.With the increase of tempering temperature,the volume fraction of reversed austenite in the tested steel increases and reaches a maximum value of41.41%at 650℃.The second phase carbides appear when the tempering temperature is higher than 600℃,besides,the quantity and the size of carbide after tempering at 650℃are larger than that at 600℃.The pitting potential decreases with the increase of tempering temperature,the precipitation of carbides reduces the pitting potential of the stainless steel,promotes the formation of metastable pitting,and reduces the corrosion resistance of 15 Cr stainless steel.

关 键 词：深冷处理 15Cr超级马氏体不锈钢(SMSS) M_(23)C_6型碳化物 腐蚀 

分 类 号：TG161[金属学及工艺—热处理]