GTAW堆焊工艺参数对2A12铝合金板堆焊焊缝组织和力学性能的影响

Influence of GTAW welding process parameters on the microstructure and properties of 2A12 aluminum alloy plate weld seam

某型装备腹部铝合金盖板在使用一段时间后易出现裂纹、磨损现象,需采用钨极氩弧焊方法进行修复,研究焊接电流和氩气流量对2A12铝合金板堆焊焊缝组织和力学性能的影响。研究结果表明,1.2 mm厚的2A12铝合金板材,当氩气流量不变时,随着电流的增大,堆焊焊缝抗拉强度先增大后减小,在焊接电流为60 A时抗拉强度最大,拉伸断裂位置为母材。当焊接电流不变时,随着氩气流量的增大,堆焊焊缝抗拉强度先增大后减小,在氩气流量为8.5 L/min时抗拉强度最大。当焊接电流60 A,保护气体(氩气)流量8.5 L/min时堆焊焊缝平均抗拉强度达到最大,为127.09 MPa。不同参数下的堆焊焊缝硬度分布趋势大致相同,都呈现M形。

In view of the fact that the aluminum alloy web of an equipment is prone to cracks and wear after certain period of use,the non-melting tungsten electrode argon arc welding method was used to repair it,and the effects of different welding currents and argon gas flow on the microstructure and mechanical properties of 2A12 aluminum alloy surfacing weld were studied.The results show that when the argon flow rate is constant,the tensile strength increases first and then decreases with the increase of current,the tensile strength is the largest when the welding current is 60 A,and the tensile fracture position is on the base metal.When the welding current is constant,the tensile strength increases first and then de-creases with the increase of argon flow,and the tensile strength is the highest when the argon flow rate is 8.5 L/min.When the welding current is 60 A and the shielding gas(argon)flow rate is 8.5 L/min,the average tensile strength of the joint reaches a maximum of 127.09 MPa.The hardness distribution trend of welded joints under different parameters is almost the same,and all of them show an M-shape.