工程机械用钢焊接接头的组织与成分分布研究

Microstructure and Composition Distribution of Welded Joint of Dual Phase Stainless Steel for Construction Machinery

采用TIG焊接工艺对工程机械用双相不锈钢进行了焊接处理,研究了焊接工艺和热处理对焊接接头焊缝区和热影响区组织与成分的影响,并分析了其作用机理。结果表明,不同焊接工艺下的焊接接头显微组织都由奥氏体和铁素体组成;未经热处理和经过700℃焊后热处理的焊接接头,奥氏体与铁素体的含量与形态分布变化并不明显;经过1000℃焊后热处理,焊接接头的组织变化较为明显,奥氏体和铁素体相分布均匀,晶粒变细,奥氏体含量明显增多,奥氏体中的Ni元素含量要高于铁素体中的含量,而铁素体中的Cr和Mo元素含量高于奥氏体中的含量。

Dual phase stainless steel is welded by TIG welding technology, the effects of welding processing and heat treatment on the microstructure and composition of the samples were studied, and its mechanism was analyzed. The results show that, the microstructure of the welded joints are composed of austenite and ferrite. The welded joint without heat treatment and heat treatment at 700℃, the change of austenite and ferrite content and distribution are not obvious; after 1000℃ heat treatment, the microstructure of the welded joint changes obviously, the distribution of austenitic and ferritic phase are more uniform, and the grain becomes refinement, and the austenite content increases, Ni content in austenite is higher than that in ferrite, Cr and Mo contents are higher than that in austenite.