脉冲微束等离子弧焊参数对丝网焊点组织与性能的影响  

Effect of Pulsed Micro-Plasma Arc Welding Parameters on Microstructure and Properties for Wire Mesh Welding Spots

作　　者：王龙 何建萍[1] 吴鑫 陶旭阳 WANG Long;HE Jianping;WU Xin;TAO Xuyang(School of Materials Engineering,Shanghai University of Engineering Science,Shanghai 201620,China)

机构地区：[1]上海工程技术大学材料工程学院,上海201620

出　　处：《轻工机械》2020年第4期28-32,42,共6页Light Industry Machinery

基　　金：国家自然科学基金资助项目(51775327);上海市科委基础研究重点资助项目(14JC1402700)。

摘　　要：为了获得具有良好性能的不锈钢丝网焊点,课题组采用脉冲微束等离子弧焊(P-MPAW)的方法,对丝径为0.35mm,孔隙为1.25 mm的方孔状丝网进行脉冲电流对接焊。利用超景深显微镜、显微硬度计和微拉伸机研究不同脉冲频率、占空比和基值电流对丝网焊点显微组织和力学性能的影响,以获得最佳的工艺参数组合。结果表明:在脉冲频率为100 Hz、占空比为50%、基值电流为1.2 A时,焊点处形成的晶粒最为细致且具有802 MPa的最高抗拉强度;当基值电流和占空比不变时,焊点晶粒随脉冲频率的增大而逐渐细化;当频率超过100 Hz时,焊点由细小等轴晶向粗大骨骼状晶转变。当脉冲频率和基值电流不变时,焊点晶粒随占空比的增大先细化后粗大,焊点力学性能先升高后下降;当脉冲频率和占空比不变时,焊点晶粒随基值电流的增大逐渐粗化,力学性能逐渐下降。In order to obtain good performance stainless steel wire mesh welding spots,pulsed micro-plasma arc welding( P-MPAW) was applied to butt welding for square hole shape wire mesh with wire diameter 0. 35 mm and hole gap 1.25 mm. Ultra depth of field microscope,microhardness tester and micro tensile machine was used to study the effects of different pulsed frequency,duty ratio and base value current on the microstructure and mechanical properties of wire mesh welding spots to obtain the best combination of welding process parameters. The result shows that the welding spots had superior microstructure and highest tensile strength of 802 MPa;The welding spots grains were gradually refined as the pulsed frequency increase when the base value current and duty ratio are constant but transformed from fine equiaxed crystals to coarse skeletal crystals when the pulsed frequency over 100 Hz;When the pulsed frequency and base value current are constant,the welding spots grains are refined first and coarsened after as the duty ratio increases,and mechanical properties of welding spots increase first and decrease later simultaneously;When the pulsed frequency and duty ratio are constant,the welding spots grains coarsened with the increase of base value current and gradually decreased with the mechanical properties.

关 键 词：不锈钢丝网 脉冲微束等离子弧焊 脉冲频率 占空比 脉冲电流 

分 类 号：TG456.2[金属学及工艺—焊接] TH142.2[一般工业技术—材料科学与工程]