工艺参数对304L不锈钢GTAW熔覆金属中铁素体含量的影响  

Influence of process parameters on ferrite content in GTAW cladding metal of 304L stainless steel

作　　者：李方亮 程尚华[1] 邵珠晶 武少杰 程方杰 Li Fangliang;Cheng Shanghua;Shao Zhujing;Wu Shaojie;Cheng Fangjie(Tianjin University,Tianjin 300072,China;Tianjin Key Laboratory of Advanced Joining Technology,Tianjin 300072,China)

机构地区：[1]天津大学,天津300072 [2]天津市现代连接技术重点实验室,天津300072

出　　处：《焊接》2020年第3期24-28,I0016,共6页Welding & Joining

基　　金：国家自然科学基金资助项目(51775372)。

摘　　要：奥氏体不锈钢焊缝金属的铁素体含量和形态会显著影响其性能,为探究焊接工艺参数对焊缝内铁素体数的影响规律,文中对304L不锈钢在氩氮混合气体保护下进行了GTAW工艺试验,研究了保护气中的氮气含量、电弧电压和焊接速度三个主要工艺参数对熔覆金属中铁素体含量及微观组织的影响规律。结果表明,增大混合保护气中氮气百分比或增大电弧电压均可使熔覆金属铁素体数减小,而增大焊接速度可使熔覆金属铁素体数增大;在多层多道焊情况下,由于存在层间的焊接热循环影响,熔覆金属平均铁素体数的实测值要低于WRC-1992的预测结果;基于磁测量原理的铁素体检测仪在测量薄板熔覆金属铁素体数时,测量结果会低于实际铁素体数,并且测量值会随焊缝金属截面积减小而减小。The content and shape of ferrite in the weld of austenitic stainless steel would significantly affect its performance.In order to explore the influence of welding parameters on the ferrite number in the weld,GTAW procedure test of 304L stainless steel was carried out under the protection of Ar-N 2 mixed shielding gas.The effects of the three main process parameters,including nitrogen content in the shielding gas,arc voltage and welding speed,on the ferrite content and the microstructure of cladding metal were studied.The results showed that increasing the percentage of nitrogen in the shielding gas or arc voltage could reduce the ferrite number of cladding metal,while increasing the welding speed could increase the ferrite number of cladding metal.In the case of multi-layer multi-pass welding,the average ferrite number in cladding metal was lower than the predictions of WRC-1992 due to the influence of welding thermal cycle between layers.When the Ferit Scope based on magnetic principle was used to measure the ferrite number in the sheet metal cladding,the result would be lower than the actual ferrite number and the measurements would reduce with the decrease of cross-sectional area of the weld.

关 键 词：奥氏体不锈钢 铁素体数 GTAW 

分 类 号：TG455[金属学及工艺—焊接]