6 mm厚不锈钢板K-TIG焊接小孔行为与接头组织及性能  

K-TIG welding keyhole behavior and microstructure and properties of welded joints of 6 mm thick stainless steel plates

作　　者：宋白钰 胡奉雅 蔡笑宇 林三宝[1] 张天泽 SONG Baiyu;HU Fengya;CAI Xiaoyu;LIN Sanbao;ZHANG Tianze(State Key Laboratory of Precision Welding&Joining of Materials and Structures,Harbin Institute of Technology,Harbin 150001,China;State Key Laboratory of Metal Materials for Marine Equipment and Their Applications,Angang Steel Company Limited,Anshan 114001,Liaoning,China)

机构地区：[1]哈尔滨工业大学,先进焊接与连接国家重点实验室,哈尔滨150001 [2]鞍钢集团公司,海洋装备用金属材料及其应用国家重点实验室,辽宁鞍山114001

出　　处：《焊接》2025年第1期1-7,共7页Welding & Joining

基　　金：国家自然科学基金资助项目(51905128);海洋装备用金属材料及其应用;国家重点实验室开放课题(SKLMEA-K202005)。

摘　　要：【目的】旨在解决目前6 mm厚板材的深熔氩弧焊(K-TIG)焊接工艺和机理研究尚缺的不足。【方法】对6 mm厚304不锈钢进行了K-TIG平板焊接,利用高动态范围工业相机观察不同焊接工艺参数下的小孔稳定性及对应的焊缝成形。【结果】发现小孔存在焊漏、稳定穿孔和未熔透3种常见状态。试验结果表明,当焊接电流为450~525 A、焊接速度为300~400 mm/min时,能获得稳定焊接小孔与良好的单面施焊双面成形全熔透焊接接头。【结论】在此基础上,微调焊接工艺参数获得完整的6 mm厚S32101双相不锈钢K-TIG对接接头,对焊接接头的显微组织进行表征,发现焊接接头由铁素体和奥氏体组成,整体仍为双相组织,但与母材相比,焊缝奥氏体含量减少。对焊接接头进行力学性能测试,发现接头整体硬度分布较为均匀,接头平均抗拉强度为658.14 MPa,达到了母材的96%;接头断后伸长率较母材有所下降,平均为23.35%,但与焊条电弧焊接头的断后伸长率相当。[Objective]The aim was to address the shortcomings in lack of researches on K-TIG welding process and mechanism for 6 mm thick stainless steel plates.[Methods]K-TIG butt welding of 304 stainless steel plates with a thickness of 6 mm was carried out.Through a high dynamic range industrial camera,stability of keyholes and corresponding weld formation under different welding parameters was investigated.[Results]It was found that there were three common states of keyholes,welding leakage,stable perforation,and lack of penetration.The test results showed that when welding current was 450~525 A and welding speed was 300~400 mm/min,full penetration welded joints with stable welding keyhole and good single-side welding with double-side formation could be obtained.[Conclusion]On this basis,complete K-TIG butt welded joints of 6 mm thick S32101 duplex stainless steel were obtained by fine-tuning welding parameters.Microstructure of welded joints was characterized.It was found that different regions of welded joints were composed of ferrite and austenite,and the whole was still a dual-phase microstructure,but austenite content in weld was reduced compared with base metal.Mechanical properties of welded joints were tested,and it was found that the overall hardness distribution of welded joints was relatively uniform,and the average tensile strength of welded joints was 658.14 MPa.

关 键 词：深熔氩弧焊 焊接小孔 304不锈钢 S32101不锈钢 显微组织 力学性能 

分 类 号：TG444[金属学及工艺—焊接]