Q345/IN825复合板焊接接头组织与性能  

Microstructure and mechanical properties of welding joints of Q345/IN825 composite plates

作　　者：杨江[1] 王斌[1] 王维[1] 丁煜瀚 李永斌[2] 刘书文[3] 

机构地区：[1]西南石油大学材料科学与工程学院,四川成都610500 [2]辽宁省新民市沈阳采油厂,辽宁新民110316 [3]四川科宏石油天然气工程有限公司,四川成都610021

出　　处：《材料热处理学报》2016年第1期150-156,共7页Transactions of Materials and Heat Treatment

基　　金：四川省高校油气田材料重点实验室开放基金(X151515KCL26);土库曼斯坦300亿项目采集输油气用复合管材腐蚀机理研究(CQ2014B-32-Z3)

摘　　要：对Q345/IN825复合板复层与基层分别采用钨极氩弧焊(GTAW)和埋弧焊(SAW)进行焊接试验。采用光学显微镜、扫描电镜对焊缝显微组织及主要合金元素分布进行了分析,利用拉伸、冲击和硬度试验测定了接头的力学性能。结果表明,基层焊缝组织为珠光体和针状铁素体,复层焊缝组织为树枝晶奥氏体,复层母材侧热影响区的奥氏体组织有明显粗化现象,复层焊缝中发现有Nb元素富集产生的析出物。接头的抗拉强度介于Q345和IN825母材强度之间,拉伸断裂发生在母材部位;焊缝金属冲击韧性低于母材;焊缝硬度高于母材硬度。焊缝金属与母材之间没有发生明显的元素迁移,确保了复层焊缝的耐蚀性。The clad and base layers of Q345 / IN825 composite plates were welded by tungsten inert gas arc and submerged arc,respectively. Microstructure and the distribution of the main alloying elements of the welded joints were analyzed by optical microscopy and scanning electron microscopy,the mechanical properties were measured by tensile,impact and hardness tests. The results show that the microstructure of the base metal weld consists of pearlite and acicular ferrite,the cladding alloy weld is composed of dendritic austenite,and the obviously coarsened austenite is observed in the heat affected zone of cladding base material. The precipitates which are formed due to the enrichment of Nb element are detected in the cladding weld. The tensile strength of the welded joints is in between the strength of Q345 steel and IN825 alloy. The tensile fracture occurs in base material. The impact toughness of the weld metal is lower than that of the base materials. The hardness of the weld is higher than that of the base materials. The diffusion of elements are not obvious between the weld and base metal,indicating that no significant effect on the corrosion resistance of the cladding weld occurs for the welding joints.

关 键 词：Q345/IN825双金属复合板 GTAW焊 显微组织 力学性能 

分 类 号：TG407[金属学及工艺—焊接]