固溶处理对异种不锈钢焊接接头组织和性能的影响

Effect of solid solution treatment on microstructure and mechanical properties of welded joints of dissimilar stainless steel

采用搅拌摩擦焊对304/430不锈钢交错对接接头进行了焊接,分析了固溶处理对焊接接头的组织和力学性能的影响。结果表明:随着固溶温度升高,基体中第二相粒子逐渐溶解,晶粒长大明显,接头抗拉强度和伸长率总体呈降低趋势。固溶温度为800℃时,第二相粒子部分溶解,接头组织发生回复和再结晶,晶粒细小,接头抗拉强度和伸长率最大,和热处理前接头对比,力学性能有较大改善,接头断裂于430不锈钢侧,具有韧性断裂特征。

Friction stir welding(FSW)was used to weld 304/430 stainless steel staggered butt joint.The effect of solution treatment on microstructure and mechanical properties of the welded joints was analyzed.The results show that with the increase of solid solution temperature,the second phase particles in the matrix gradually dissolve,the grain growth is obvious,and the tensile strength and elongation of the welded joints decrease as a whole.When the solid solution temperature is 800℃,the second phase particles are partially dissolved,the microstructure of the welded joints is recovered and recrystallized,the grain size is fine,the tensile strength and elongation of the welded joints are the highest.Compared with the welded joints before heat treatment,the mechanical properties of the welded joints are improved greatly.The welded joints are fractured on the side of 430 stainless steel and has the characteristics of ductile fracture.