430/304不锈钢搅拌摩擦焊搭接接头的组织和力学性能

Microstructure and Mechanical Property of 430/304 Stainless Steels Friction Stir Welded Lap Joint

采用搅拌摩擦焊技术,以1200 r/min的搅拌转速对1 mm厚的430和304不锈钢板进行焊接,研究焊接速度对搭接接头组织和力学性能的影响。结果表明:随着焊接速度增加,接头界面两侧Hook钩尺寸减小,过渡层厚度减小,界面由锯齿状逐步转变为平直状。所有试样均断裂于焊缝附近的430不锈钢母材上,焊接速度为50 mm/min焊接接头的剪切强度最大,搭接接头界面区的冶金反应起主导作用,机械连接起促进作用。

The 1mm thick 430 and 304 stainless steel sheets were welded by friction stir welding technology with rotational speed of 1200 r/min and the effects of welding speed on the microstructure and mechanical property of the lap joint were studied.The results show that with the increase of welding speed,the size of"hook"groove at both sides of the interface decreases and the thickness of the transition layer decreases,and the interface gradually changes from serrated structure to straight structure.All samples are fractured at the 430 stainless steel near the weld.The shear strength of the welded joint is the highest when the welding speed is 50 mm/min.The metallurgical reaction at the interface of the lap joint plays a leading role and mechanical connection plays a promoting role.