铝/钢双脉冲MIG熔-钎焊中电弧作用方式对焊缝成形与力学性能的影响

进行了6061铝合金/304不锈钢异种金属板材双脉冲MIG熔-钎焊搭接试验,利用高速摄像和电信号同步采集系统对焊接过程中的电弧形态和电信号进行了采集,研究了电弧作用方式(焊枪倾角与电弧作用位置)对焊缝成形和接头力学性能的影响.结果表明,电弧作用方式的不同对电弧形态、焊缝成形和接头力学性能有显著影响,焊枪前倾角为20°,侧倾角为0°时,焊缝成形对电弧位置的变化敏感;焊枪前倾角为20°,侧倾角为20°时,焊缝成形对电弧位置变化不敏感.前者电弧作用方式下,焊丝末端距铝钢搭接处距离为L. L=-1,0,1 mm时,接头具有较高抗剪强度;后者电弧作用方式下,L=0,1 mm时,接头具有较高抗剪强度.电弧作用位置是影响接头抗剪强度的关键因素,它也会影响金属间化合物层的厚度.对双脉冲MIG焊焊接过程中电弧作用方式对焊缝成形影响的研究有助于对铝钢异种金属焊接过程中的热量分配进行有效控制.

Effect of arc action mode on weld formation and mechanical properties in joining aluminum and steel by molten-brazing operating at pulse-on-pulse mode

Experiment of joining 6061 aluminum alloy and 304 stainless steel plate by molten-brazing operating at pulse-on-pulse welding mode was carried out and lap joints were obtained. The arc shape and welding current as well as voltage was acquired by high speed camera and electric signal acquisition synchronous system. The effect of the action mode of arc(inclination angle of torch and position of arc)on the weld formationand mechanical properties of the joint was conducted.The result showed that different action modes of arc actually had significant influence on the arc shape, weld formation and mechanical properties of the joint.When the anteversion angle is 20°and the heeling angle is 0°, the weld formation is sensitive to the position of arc. While with the anteversion angle of 20°and heeling angle of 0°, the weld formation is insensitive to the position of arc. Under the former condition, when L is -1 mm, 0 mm, 1 mm, the joint of aluminum and stainless steel has higher strength while under the later condition, the joint of aluminum and stainless steel has higher strength when L is 0 mm and 1 mm. The position the arc performs is the key factor to the shear strength of the joint and it also has effect on the thickness of the interface layer. The study of effect of the action way of arc on weld forming and mechanical properties helps us make effective control of the heat distribution in the process of joining aluminum and steel.