矫形量对6N01铝合金矫形接头组织及性能的影响

Effect of Straightening Size on Microstructure and Property of 6N01 Aluminum Alloy Straightened Joint

采用火焰水冷方法对车体常用6N01铝合金焊接接头进行矫形,研究了不同的矫形量对接头组织、力学性能和疲劳性能的影响。结果表明:火焰热引起时效使6N01焊接接头热影响区和母材基体组织中Mg2Si沉淀相析出长大,导致焊接接头硬度和抗拉强度随着矫形量的增加而减小,但焊接接头的疲劳性能因析出Mg2Si沉淀相对疲劳源滑移和疲劳裂纹扩展的阻碍,疲劳寿命随着矫形量的增加而增加。

Straightening combined with flame-water cooling method was used to straighten 6N01 aluminum alloy welded joint used for vehicle body and effects of straightening size on its microstructure, mechanical properties and fatigue property were studied. Results show that the flame induces the precipitation and grow of the Mg2 Si phase on the heat affected zone and Al substrate because of the thermal aging 6N01 aluminum alloy welded joints, and thus this leads the decrease of microhardness and tensile strength of the 6N01 aluminum alloy welded joint with the increase of the straightening size.However, the fatigue property of the welded joint is improved because the Mg2 Si precipitation inhibits the initiation and propagation of the fatigue crack, and the fatigue life increases with the increase of the straightening size.