S32760超级双相不锈钢管材焊接接头组织及腐蚀原因分析  

Analysis on Microstructure and Corrosion Reason of S32760 Super Duplex Stainless Steels Pipe Welded Joints

作　　者：程巨强[1] 弥国华 刘志学[1] 马海峰 郭旺 

机构地区：[1]西安工业大学材料与化工学院,西安710032 [2]珠海巨涛石油服务有限公司,广东珠海518068

出　　处：《焊管》2014年第5期20-23,共4页Welded Pipe and Tube

摘　　要：观察了氩弧焊S32760双相不锈钢管材焊接接头各区的组织,分析了焊接接头腐蚀的原因,测定了焊接接头奥氏体和铁素体相比例。结果表明,氩弧焊焊后不进行热处理,焊缝和热影响区组织均为奥氏体和铁素体双相组织,存在少量的σ相,焊缝金属的奥氏体组织比例为64%,铁素体比例为36%,母材部分奥氏体比例为52%,铁素体比例在48%。双相不锈钢焊接接头熔合线结合良好,焊缝热影响区宽度较小。焊接接头出现孔蚀的原因与焊后冷却速度过慢、焊缝组织中奥氏体量过多及其组织中析出σ相有关。Welded joints microstructure of S32760 super duplex stainless steels pipe was observed and the corrosion cause of welded joint was analyzed, the ferrite and austenite phase ratio was determined. The results showed that without heat treatment after GTAW welding, the microstructure of weld and HAZ both are ferrite and austenite duplex phase microstructure, and a small amount of sigma phase exist. The austenite phase content of weld metal is 64%, ferrite phase is 36%, the austenite phase content of parent metal is 52%, and ferrite phase is 48%. The fusion line combination of duplex stainless steel welded joint is good, and the width of weld heat affected zone is smaller. The reasons for pitting corrosion in welded joints is relevant to too slow cooling rate, austenite content is too much and precipitation sigma phase after welding.

关 键 词：S32760超级双相不锈钢 氩弧焊 焊接接头 腐蚀 

分 类 号：TG454[金属学及工艺—焊接]