焊接速度对铝钢异种金属激光填丝熔钎焊性能的影响

Effect of Welding Speed on the Properties of Aluminum/Steel Dissimilar Metal by Laser Wire Fusion Brazing

采用不同的焊接速度对铝合金E600及汽车车身用镀锌钢板DP590D+Z进行激光填丝熔钎焊试验,焊接材料选用ER4047焊丝,分别对不同焊接速度下的焊缝成形质量、金属间化合物层厚度及力学性能进行了分析研究。结果表明:选择适当的焊接参数时,利用激光填丝熔钎焊可获得成形良好且具有一定抗拉强度的熔钎焊接头。为保证焊缝接头的性能,需控制界面处主要成分为FeAl_(2)和FeAl_(3)的金属间化合物层的厚度,随着焊接速度的提升,线能量下降,金属间化合物层厚度随之减小。综合考虑接头的线载荷及生产效率,最优焊接速度为1.5 m/min,此时线载荷约为197 N/mm,换算成铝合金强度为219 MPa,相当于母材强度的81%。

Aluminum alloy E600 and galvanized steel DP590D+Z for automotive body were tested by laser wire welding at different welding speeds.ER4047 wire was selected as welding material.The weld morphology,intermetallic compound layer thickness and mechanical properties were analyzed at different welding speeds.The test results show that the brazing joint with defects free and certain tensile strength can be obtained by laser wirefusion brazing with appropriate welding parameters.In order to ensure the performance of the weld joint,it was necessary to control the intermetallic compound thickness of FeAl_(2) and FeAl_(3) at the interface.With the increase of welding speed,the line energy and the intermetallic compound thickness decreased.On the basis of meeting the requirements of aluminum and steel dissimilar metal welding forming,the welding speed can be selected as far as possible to control the thickness and ensure the performance of the joint.Considering the linear load of the joint and production efficiency,the optimal welding speed was 1.5 m/min.The linear load was about 197 N/mm,and the converted strength of aluminum alloy was 219 MPa,which was equivalent to 81%of the strength of the base metal.