UNS S32304双相不锈钢等离子弧焊接头的组织及其耐点蚀性能  

MICROSTURE AND PITTING CORROSION RESISTANCE OF UNS S32304 DUPLEX STAINLESS STEELS WELDED JOINT WITH PLASMA-ARC WELDING

作　　者：洪巨锋[1] 谭华[1] 陈林豆[1] 李劲[1] 李莉[2] 蒋益明[1] 

机构地区：[1]复旦大学材料科学系,上海200433 [2]复旦大学分析测试中心,上海200433

出　　处：《金属学报》2011年第11期1445-1449,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目50871031.51071049.51131008和51134010;上海市高新技术产业重点项目资助~~

摘　　要：采用恒电位临界点蚀温度(CPT)法,利用OM,SEM,EDX和恒电位极化技术等研究了等离子弧焊接对双相不锈钢UNSS32304焊接接头微观组织及其耐点蚀性能的影响.结果表明,焊接接头热影响区和熔合区微观组织较母材相比发生了显著变化,两相比例严重失衡,铁素体所占比例均大于70%;两区域微观组织形态发生明显变化.且在铁素体晶粒内及两相相界处析出大量氮化物;焊接接头的耐点蚀性能明显下降,点蚀优先发生在高温热影响区所在的铁素体晶粒内.Microstructure and pitting corrosion resistance of UNS S32304 duplex stainless steels welded joint with plasma-arc welding（PAW） were studied by means of OM.SEM,energy dispersive X ray spectroscopy（EDX） and potentiostatic electrochemical technique.The results show that the microstructures of the heat-affected zone（HAZ） and fusion zone differ from the base metal greatly, with ferrite fraction greater than 70%.Furthermore,a lot of nitrides are precipitated at the interface between ferrite and austenite phases and inside the ferrite grains.Consequently,pitting corrosion resistance of the welded joint declines obviously and pitting preferentially occurs at ferrite phase in the high temperature HAZ near the fusion line.

关 键 词：双相不锈钢 等离子弧焊 微观组织 点蚀 

分 类 号：TG142.33[一般工业技术—材料科学与工程] TG401[金属学及工艺—金属材料]