A7N01S-T5铝合金激光-MIG复合焊接头低温韧性研究

A7N01S-T5铝合金激光-MIG复合焊接头低温韧性研究 Research on low temperature toughness of A7N01S-T5 aluminum alloy laser-MIG hybrid welding joints 佘鹏 SHE Peng 1 first-author 孙维光 SUN Weiguang 1 马传平 MA Chuanping 2 中车青岛四方机车车辆股份有限公司 中车青岛四方机车车辆股份有限公司 CRRC Qingdao Sifang Co.,Ltd. CRRC Qingdao Sifang Co.,Ltd. 西南交通大学材料科学与工程学院 西南交通大学材料科学与工程学院 College of Materials Science and Engineering,Southwest Jiaotong University College of Materials Science and Engineering,Southwest Jiaotong University 针对高速列车用A7N01S-T5铝合金的激光-MIG电弧复合焊接接头的焊缝(W)、热影响区(HAZ)和母材(BM)分别在20℃、0℃、-20℃、-40℃及-60℃条件下进行冲击韧性和断裂韧性试验研究。结果表明:在相同温度下,热影响区的冲击韧性和断裂韧性最好,母材次之,焊缝最差。随着温度的降低,激光-MIG复合焊接头三个区的冲击韧性和断裂韧性都有一定程度的提高,但是变化幅度小。热影响区和母材的断口韧窝尺寸大于焊缝,在断裂过程中能产生较大变形来抵抗裂纹的扩展,吸收更多的能量,表现出良好的断裂韧性。 The impact toughness and fracture toughness of laser-MIG hybrid welding joints of A7N01S-T5 aluminum alloy for high-speed trains under the temperatures of 20 ℃,0 ℃,-20 ℃,-40 ℃ and -60 ℃ were carried out. The results showed that at the same temperature,the impact toughness and fracture toughness of the heat affected zone（HAZ） was the best,the base metal（BM） was the second,and the weld metal（W） was the worst. With the decrease of temperature,the impact toughness and fracture toughness of the three zones（HAZ,BM and WM） of laser-MIG hybrid welding joints had been improved to a certain extent,but the changes were small.The size of toughness dimples on fracture surface in the heat affected zone and the base metal were larger than that of the weld metal. During the fracture process,large dimples could produce large deformation to resist the crack growth,absorb more energy,and show good fracture toughness. A7N01S-T5铝合金 激光-MIG复合焊 低温韧性 抗裂纹扩展 韧窝 A7N01S-T5 aluminum alloy laser-MIG hybrid welding low temperature toughness crack growth resistance dimples TG457.14 2022-03-08 4 50