6061-T6铝合金MIG焊接工艺研究

Study on MIG Welding Process of 6061-T6 Aluminum Alloy

以4mm厚6061-T6铝合金轧制板材为研究对象，通过改变焊接线能量与送丝速度，研究了不同工艺参数下接头的显微组织和力学性能。结果表明，HAZ宽度和熔合区晶粒大小随线能量的增大而增大：当线能量为297J／mm时焊接接头的抗拉强度为213MPa，达到母材强度的73％。熔宽对送丝速度的变化较余高和熔深更敏感，送丝速度位于7．4-8．2m／min范围内时，焊缝成形较好；在送丝速度为8．3m／min时获得最大的抗拉强度239MPa。断裂发生在热影响区，属于韧性断裂，表明热影响区为焊接接头最薄弱的位置。

Taking 6061-T6 aluminum alloy rolling plate with 4 mm thickness as the research object, the MIG welding process was studied through changing the welding line energy and wire feed rate. The microstructure and mechanical properties of the joints were studied under the different process parameters. The results show that the HAZ width and grain size of the fusion zone increase with the increase of welding line energy. When the line energy is 297J/mm, the tensile strength of the welded joint is 213 MPa, which reaches up to 73% of the parent material＇s strength. Weld poll width is more sensitive than weld reinforcement and weld penetration with the change of wire feed rate. Weld forming is good when the wire feed rate is within the range of 7.4-8.2 m/min. When the wire feed rate is 8.3 m/min, the maximum tensile strength value is 239MPa, and the ductile fracture appears in the heat affected zone, which indicates that the heat affected zone is the weakest position of the weld joint.