穿孔型等离子弧自熔焊工艺对N6镍合金焊缝成形及性能的影响  

Effect of keyhole mode plasma arc welding process on formation of weld and mechanical properties of N6 nickel alloy

作　　者：柴廷玺[1] 徐宏彤[1] 王希靖 张亮亮 晏丽琴[1] Chai Tingxi;Xu Hongtong;Wang Xijing;Zhang Liangliang;Yan Liqin(Lanzhou City University,Lanzhou 730070,China;State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou 730050,China)

机构地区：[1]兰州城市学院,兰州730070 [2]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》2021年第8期29-36,63,共9页Welding & Joining

基　　金：甘肃省高等学校科研项目(2020A-128);兰州城市学院博士科研启动基金项目(LZCU-BS2018-06);甘肃省高校协同创新科技团队支持计划资助项目(2017C-21)。

摘　　要：以6.0 mm厚的N6镍合金为试验材料,采用等离子弧自熔焊方法开展全熔透焊接工艺试验研究。利用OM,SEM,拉伸试验机等设备研究焊接电流、焊接速度、离子气流量、焊接热输入对焊缝成形及力学性能的影响。结果表明,采用正交设计优化的工艺参数进行焊接,焊缝成形美观,接头平均抗拉强度302 MPa,接头系数达87.3%;主要工艺参数对N6焊缝成形及力学性能有重要影响。焊接电流、离子气流量起协同作用,一定范围内,熔宽、熔深随焊接电流、离子气流量增大而增大,而随焊接速度增大而下降;但焊接速度超过一定范围,继续增大焊接速度,焊缝背面产生“驼峰”;焊接热输入从1.5 kJ/mm增至2.14 kJ/mm焊缝区晶粒急剧长大,平均晶粒度从5.9降至2.3,而焊接接头抗拉强度呈先增大后下降趋势,拉伸断口从韧性-解理混合断裂模式向脆性断裂模式转变。Full penetration welding process experiments were carried out on 6.0 mm N6 nickel alloy by plasma arc welding.Effects of welding current,welding speed,ion gas flow rate and welding heat input on formation of weld and mechanical properties were investigated by OM,SEM and tensile testing machine.The results showed that welding parameters optimized by orthogonal design was used to obtain well formation of weld,the average tensile strength of the joint was 302 MPa,and the joint coefficient was 87.3%.The main welding parameters had a critical influence on formation of weld and mechanical properties.There was a synergistic effect between welding current and ion gas flow.In a certain range,the weld width and penetration increased with the increase of welding current and ion gas flow,but decreased with the increase of welding speed.However,if the welding speed exceeded a certain value and the welding speed continued to increase,the back of the weld produced a“hump”.The welding heat input increased from 1.5 kJ/mm to 2.14 kJ/mm,the grain size in the weld area increased sharply,and the grain size decreased from 5.9 to 2.3,while the tensile strength of the welded joint increased first and then decreased.The tensile fracture changed from the mixed fracture mode of toughness cleavage to the brittle intergranular fracture mode.

关 键 词：N6镍合金 等离子弧焊 焊接工艺参数 焊缝成形 力学性能 

分 类 号：TG456.2[金属学及工艺—焊接]