焊接电流对LD10CS焊接接头组织和性能的影响

Effect of welding current on microstructure and properties of welding joint of LD10CS

对LD10CS铝合金进行TIG焊,利用金相、硬度和腐蚀实验,研究不同焊接电流对LD10CS铝合金焊接接头组织和性能的影响。结果表明:当电流过大时,热输入量大导致晶粒粗大,且过大的焊接电流还可能造成合金元素的烧损;而电流过小时,冷却速度过快,第二相无法充分均匀地析出;当焊接电流为230 A,焊接接头的组织为细小均匀的α-Al固溶体,并且在其上分布着均匀、细小、弥散的第二相,使接头具有较好的硬度和耐蚀性。

The TIG welding was applied on LDIOCS aluminum alloy plate. The effect of welding current on microstructure and properties of welded joint was investigated by means of optical microscope, hardness and corrosion experiment. The results show that when the current is too high, the large heat input causes coarse grain, and the high welding current may cause the loss of alloy elements. But when the current is too low, and the cooling rate is too fast, the second phase is unable to sufficiently and homogeneously precipitate. When the welding current is 230 A, the microstructure of the welded joint is the tiny and uniform α- A1 solid solution with second phase uniformly distributing on it which leads to higher hardness and corrosion resistance.