304不锈钢低温盐浴氮化处理后的微观结构及耐冲刷腐蚀性  

Microstructure and erosion-corrosion property of 304 stainless steel treated by salt bath nitriding at low temperature

作　　者：黄润波[1] 王院生[1] 钟司[2] 钟睿[1] 王均[1] 

机构地区：[1]四川大学制造科学与工程学院,四川成都610065 [2]西南交通大学材料先进教育部重点实验室,四川成都610031

出　　处：《电镀与涂饰》2012年第10期41-44,共4页Electroplating & Finishing

摘　　要：在430°C下对304奥氏体不锈钢进行低温盐浴氮化处理,并用X射线衍射(XRD)、光学显微镜(OM)、能谱(EDS)、扫描电镜(SEM)和显微硬度计研究了氮化时间对渗氮层厚度、组织结构、显微硬度和耐冲刷腐蚀性能的影响。结果表明,渗氮层厚度和表面显微硬度均随渗氮时间的延长而增加。氮化时间为1h时,氮化层仅为单一的S相;氮化16h时,氮化层由CrN和S两相混合。氮化层中的CrN随渗氮时间延长而增多,氮化40h时氮化层析出大量CrN。盐浴渗氮处理后,304不锈钢的耐冲刷腐蚀性能得到了一定的改善。在430°C氮化16h,其耐蚀性能最好。随着渗氮时间的继续增加,304不锈钢的耐冲刷腐蚀性能降低。Austenitic 304 stainless steel was nitrided in a salt bath at 430 ℃. The effect of nitriding time on thickness, microstructure, microhardness, and erosion-corrosion resistance of the nitrided layer was studied by X-ray diffraction （XRD）, optical microscopy （OM）, energy- dispersive spectroscopy （EDS）, scanning electron microscopy （SEM）, and microhardness tester. The results showed that the thickness and microhardness of nitrided layer are increased with extending nitriding time. The nitrided layer only contains a single S phase after nitriding for 1 h, but is composed of S phase and CrN for 16 h. The content of CrN in nitrided layer is increased with prolonging nitriding time. A larger amount of CrN segregates after nitriding for 40 h. The erosion-corrosion resistance of 304 stainless steel is improved by nitriding, and is the best by nitriding at 430 ℃ for 16 h, but is decreased with further increasing nitriding time.

关 键 词：奥氏体不锈钢 盐浴氮化 显微组织 冲刷腐蚀 

分 类 号：TG174.44[金属学及工艺—金属表面处理]