热输入对铝合金/不锈钢双丝冷金属过渡熔钎焊接头组织及性能的影响

Effect of Heat Input on Microstructure and Properties of Aluminum Alloy/Stainless Steel Cold Metal Transfer Twin Fusion Brazing Joint

采用双丝冷金属过渡(CMT)熔钎焊工艺对5083铝合金和304不锈钢进行对接焊试验,在保证焊缝成形良好的条件下,研究了焊接热输入对接头金属间化合物(IMC)层厚度和拉伸性能的影响,并与单丝CMT熔钎焊接头进行对比。结果表明:双丝和单丝CMT熔钎焊接头焊缝获得良好成形质量的热输入范围分别为213.8~486.0,379.6~590.6 J·mm^(-1);双丝CMT和单丝CMT熔钎焊接头界面处的IMC均为FeAl_(3)相;随着热输入的增加,单丝或双丝CMT熔钎焊接头IMC层厚度增加,抗拉强度降低;单丝CMT熔钎焊接头IMC层的最小厚度为9.59μm,此时接头的抗拉强度最大,为76 MPa,而双丝CMT熔钎焊接头IMC层的最小厚度为3.36μm,此时接头的抗拉强度最大,为109 MPa。

The butt welding of 5083 aluminum alloy and 304 stainless steel was carried out by the cold metal transfer(CMT)twin fusion brazing process.Under the condition of ensuring good weld formation,the influence of welding heat input on the intermetallic compound(MC)layer thickness and tensile properties of the joint was studied and compared with that of the CMT single fusion brazing joint.The results show that the heat inputs of CMT twin and single fusion brazing joint weld to obtain good forming quality were 213.8-486.0,379.6-590.6 J·mm^(-1),respectively.IMC at the interface of CMT twin and single fusion brazing joints was FeAl_(3) phase.With increasing heat input,the thickness of IMC layer of CMT twin or single fusion brazing joints increased,and the tensile strength decreased.The minimum thickness of IMC layer of CMT single fusion brazing joint was 9.59μm,and at this time,the joint had the largest tensile strength of 76 MPa.The minimum thickness of IMC layer of CMT twin fusion brazing joint was 3.36μm,and at this time,the joint had the largest tensile strength of 109 MPa.