氮化时间对17-4PH不锈钢显微组织和冲蚀性能的研究  

Effects of Time on Microstructure and Erosion Corrosion Behaviour of Liquid Nitrided 17-4PH Stainless Steel

作　　者：李明星[1] 黄润波[1] 王均[1] 范洪远[1] 熊计[1] 

机构地区：[1]四川大学制造学院,四川成都610065

出　　处：《四川大学学报（工程科学版）》2013年第S1期163-167,共5页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金资助项目(50901047)

摘　　要：针对反应堆内17-4PH不锈钢耐磨性不足的问题,对该不锈钢在430℃进行了不同时间低温液体氮化来研究氮化时间对不锈钢渗层显微组织和冲蚀性能的研究。研究结果表明,氮化层的组织和氮化时间有密切关系。氮化4 h后,渗层的组织为扩展奥氏体和扩展马氏体,氮化8～16 h后,渗层析出Fe4N,氮化40 h后,渗层内大量析出Fe2N,并由于N的渗入导致大量裂纹的产生。液体氮化后不锈钢的硬度由未氮化的309 HV0.1提高到1 100 HV0.1。液体氮化显著提高不锈钢的抗冲蚀能力,氮化4 h的冲蚀失重是未氮化的10%。To improve the erosion corrosion resistance of 17-4 PH martensitic precipitation hardening stainless steel,the liquid nitriding of stainless steel was conducted at 430 ℃ for different time using a complex chemical heat-treatment,and the erosion corrosion resistance of the nitrided samples was evaluated.Experimental results showed that the main phase of the nitrided layer is expanded austenite(S),CrN,Fe4N and Fe2N,when 17-4PH stainless steel is subjected to complex salt bathing nitriding.The nitrided layer depth is thickened intensively with increasing nitrding temperature.The salt bath nitriding can effectively improve the surface hardness.The maximum values measured from the treated surface are observed to be approximate 1 100 HV0.1 for 40 hours from the untreated material(309 HV0.1).Low temperature nitriding can improve the erosion corrosion resistance against two phases flow.After nitrided for 4 hours,the sample has the best corrosion resistance than others.

关 键 词：17-4PH不锈钢 低温液体氮化 显微组织 冲蚀性能 

分 类 号：TG156.82[金属学及工艺—热处理]