(東北大學(xué) 材料與冶金學(xué)院, 沈陽 110004)
摘 要: 在商用6005A鋁合金的基礎(chǔ)上，設(shè)計(jì)開發(fā)一種新型高速列車用鋁合金材料，并采用正交試驗(yàn)考察Mg、Mn、Cu和Cr元素含量對MIG焊后焊接接頭強(qiáng)度的影響規(guī)律，分析合金添加元素改善材料耐蝕性的作用機(jī)理，確定優(yōu)化的合金成分。結(jié)果表明：自制的6005A鋁合金可與焊絲ER5356實(shí)現(xiàn)良好焊接，焊接熱影響區(qū)內(nèi)晶粒無過分長大現(xiàn)象，焊接接頭抗拉強(qiáng)度可達(dá)237 MPa，為商用6005A鋁合金接頭強(qiáng)度的1.25倍。拉伸斷口呈典型韌性斷裂特征；合金元素的適量添加可有效提高合金的自腐蝕電位，顯著改善耐大氣等常規(guī)介質(zhì)腐蝕的能力；研究確定的最佳6005A鋁合金的化學(xué)成分(質(zhì)量分?jǐn)?shù))為Mg 1.0%、Si 0.8%、Mn 0.70%、Cu 0.40%、Cr 0.20%、鋁余量。
關(guān)鍵字: 6005A鋁合金；焊接性；正交試驗(yàn)；抗拉強(qiáng)度；自腐蝕電位
（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
