不同组元活性剂对不锈钢脉冲TIG焊熔池表面张力的影响  

Effect of different component active fluxes on surface tension of weld pool in stainless steel

作　　者：顾玉芬[1] 边春红 李春凯[1] 石玗[1] GU Yufen;BIAN Chunhong;LI Chunkai;SHI Yu(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou,730050,China)

机构地区：[1]兰州理工大学,省部共建有色金属先进加工与再利用国家重点实验室,兰州730050

出　　处：《焊接学报》2020年第6期48-53,I0003,I0004,共8页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51765037);甘肃省引导科技创新发展专项基金项目(2019ZX-08);甘肃省基础研究创新群体(17JR5RA107);省部共建有色金属先进加工与再利用国家重点实验室开放课题(SKLAB02019009).

摘　　要：准确获取焊接条件下熔池金属表面张力的基础数据对深入理解焊接过程中熔池金属流动及传热机制、焊缝缺陷形成等具有重要意义,但实时测量十分困难.采用激光视觉法测量了单一组元(TiO2,CaF2)及二组元(30%TiO2+70%CaF2,70%TiO2+30%CaF2)活性剂下304不锈钢脉冲钨极氩弧焊熔池振荡频率,并根据特定模式下熔池特征频率与表面张力的解析模型计算了熔池金属表面张力,分析了不同组元活性剂对熔池金属平均表面张力的影响规律,在此基础上研究了不同组元活性剂对焊缝熔深的影响和增加熔深的机理.结果表明,TiO2能够改变熔池金属表面张力温度梯度,使熔池金属流动方向发生变化,CaF2能够降低熔池金属表面张力绝对值,使熔池金属流速增加;二组元活性剂增加熔深是熔池金属流速增加和表面张力温度梯度改变共同作用的结果.Acquiring the basic data of the surface tension of molten metal under welding condition is of great significance for understanding the physical mechanism of weld process,such as metal flow behavior,heat transfer mechanism and defect formation.However,real-time measurement is very difficult.The oscillating frequency of weld pool in 304 stainless steel with single component(TiO2,CaF2)and two component(30%TiO2+70%CaF2,70%TiO2+30%CaF2)activating fluxes was measured by laser-vision method.According to the analytical model of the characteristic frequency and surface tension of the molten metal in a specific mode the surface tension of the molten metal was calculated.The influence of different components of the activating fluxes on the average surface tension of the molten metal is analyzed.Experimental results revealed that TiO2 activating flux can convert the surface tension gradient and change the flow direction of the molten metal.CaF2 activating flux can reduce the absolute value of surface tension and increase the flow velocity of the weld pool.The increase of penetration in two component activating flux is the result of the combination of the increase of the flow velocity of the weld pool and the change of surface tension temperature gradient.

关 键 词：钨极氩弧焊 多组元活性剂 表面张力 熔深 流速 

分 类 号：TG444[金属学及工艺—焊接]