(东北大学 材料与冶金学院, 沈阳 110004)
摘 要: 在商用6005A铝合金的基础上，设计开发一种新型高速列车用铝合金材料，并采用正交试验考察Mg、Mn、Cu和Cr元素含量对MIG焊后焊接接头强度的影响规律，分析合金添加元素改善材料耐蚀性的作用机理，确定优化的合金成分。结果表明：自制的6005A铝合金可与焊丝ER5356实现良好焊接，焊接热影响区内晶粒无过分长大现象，焊接接头抗拉强度可达237 MPa，为商用6005A铝合金接头强度的1.25倍。拉伸断口呈典型韧性断裂特征；合金元素的适量添加可有效提高合金的自腐蚀电位，显著改善耐大气等常规介质腐蚀的能力；研究确定的最佳6005A铝合金的化学成分(质量分数)为Mg 1.0%、Si 0.8%、Mn 0.70%、Cu 0.40%、Cr 0.20%、铝余量。
关键字: 6005A铝合金；焊接性；正交试验；抗拉强度；自腐蚀电位
（School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China）
Abstract:A new kind of aluminum alloy welded was prepared based on 6005A-T6 commercial aluminum alloys. Through the orthogonal test, the influences of alloy element Mg, Mn, Cu and Cr on the strength of welded joint were investigated and the corrosion resistance of alloying element was analyzed. The results show that the wire of ER5356 can achieve good connection with self-made 6005A-T6 aluminum alloys. The grain growth in heat affected zone (HAZ) is not obvious, the tensile strength of the welded joints reaches 237 MPa, which is 1.25 times of that of commercial 6005A alloy, and the fracture shows typical characteristics of fracture toughness. The addition elements improve the corrosion potential, it can significantly improve the resistance of atmospheric corrosion. The optimum compositions(mass fraction) for 6005A alloy are identified as Mg 1.0%, Si 0.8%, Mn 0.70%, Cu 0.40%, Cr 0.20% and balance Al.
Key words: 6005A aluminium alloy; weldability; orthogonal experiment; tensile strength; corrosion potential
