奥氏体不锈钢双T型接头熔透工艺优化与组织分析  

Optimization of Fusion Penetration Process and Microstructure Analysis of Austenitic Stainless Steel Double T-shaped Joints

作　　者：卢宜 杨凯 刘园 LU Yi;YANG Kai;LIU Yuan(CSIC Haisheng Technology Co.,Ltd.,Yichang 443000,China)

机构地区：[1]中船重工海声科技有限公司,湖北宜昌443000

出　　处：《新技术新工艺》2024年第7期58-62,共5页New Technology & New Process

摘　　要：针对奥氏体不锈钢中厚板双T型接头的熔透工艺,采用高效率的药芯焊丝气体保护焊工艺(FCAW)替代手工焊条电弧焊工艺(SMAW),基于X射线探伤、宏观形貌及微观金相分析对接头内部质量和组织演变进行了研究。试验结果表明,根部焊道未熔合和未焊透、层间夹渣及气孔是双T型接头最频繁出现的内部质量缺陷。经试验验证,采用合适的坡口形式及焊层厚度可获得内部质量优良的双T型焊接接头;焊接接头母材区组织为等轴奥氏体组织和少量热轧残留的高温δ铁素体组织。焊接接头热影响区组织为少量沿奥氏体晶界析出的δ铁素体,该区域组织演变最为复杂,分Ⅰ区、Ⅱ区和Ⅲ区。焊接接头焊缝区组织为板条状的δ铁素体及沿铁素体凝固边界分布的奥氏体组织,通过其组织形态可推断焊缝区组织凝固模式为FA模式。An efficient FCAW welding method was adopted for the penetration process of double T-shaped joints in austenitic stainless steel plates which replaced SMAW.Based on X-ray inspection,macroscopic morphology,and microscopic metallographic analysis,the internal quality and microstructure evolution of the joints were studied.The experimental results indicated that incomplete fusion and penetration of the root weld,interlayer slag inclusion,and porosity were the most frequent internal quality defects in double T joints.Through experimental verification,it has been found that appropriate groove forms and weld layer thickness could obtain double T-shaped welded joints with excellent internal quality;the microstructure of the base metal zone of the welded joint was equiaxed austenite and a small amount of high-temperature residual hot rolled materialδferrite structure.The microstructure of the heat affected zone of the welded joint was a small amount ofδFerrite precipitation along the austenite grain boundaries,the most complex tissue evolution was in this region,and it was divided into zoneⅠ,zoneⅡ,and zoneⅢ.The weld zone of the welded joint was in the form of lathδferrite and the microstructure of ferrite and austenite distributed along the solidification boundary.It could be inferred from its morphology that the solidification mode of the weld zone was FA mode.

关 键 词：奥氏体不锈钢 T型接头 熔透工艺 接头设计 微观组织 焊缝质量 

分 类 号：TG44[金属学及工艺—焊接]