不锈钢超声-脉冲TIG焊缝的组织与性能

Microstructure and mechanical behaviors of stainless steel weld metal by ultrasonic assisted pulse TIG welding technology

关键词:  不锈钢  超声振动  晶粒细化  力学性能

Key words:  stainless steel  ultrasonic vibration  grain refinement  mechanical property

摘要:

超声辅助TIG焊是一种新型高效焊接方法.前期研究中采用的是直流,而实际焊接中多用脉冲.采用超声辅助脉冲TIG焊方法焊接不锈钢1Cr18Ni9Ti,对焊接接头的组织和性能进行了分析,讨论了焊缝熔深增加、组织细化的机理.结果表明,施加超声振动后,焊缝熔深增加1倍以上,焊缝区组织细化,基值电流期间电弧压缩明显,接头抗拉强度和断后伸长率都有所提高.分析认为声流力是焊缝熔深增加的主要动力,声空化与声流搅拌的共同作用使焊缝组织细化.

Abstract:

Ultrasonic assisted TIG welding is a new technology with high efficiency.In previous study, direct current was used.However, pulse current was expected in actual welding production.In this study, ultrasonic assisted pulse TIG welding technology was applied to weld 1Cr18Ni9Ti austenitic stainless steel.Microstructure and mechanical properties of the joints were analyzed.The reasons for weld penetration increasing and microstructure refinement were discussed.Experimental results indicated that the welding penetration with ultrasonic vibration was double of that without it.The microstructure of the weld zone was refined and the arc shape was compressed in base current period.The ultimate tensile strength and elongation were higher than that without ultrasonic vibration.Weld penetration increasing is perhaps attributed to acoustic streaming as the main driving force.The refinement of microstructure may be caused by the corporate effects of acoustic cavitation and acoustic streaming.