22MnB5钢激光焊接接头冷变形行为研究

Study on Cold Deformation Behavior of Weld Joints of 22MnB5 Steel by Laser Welding

采用金相显微镜、扫描电子显微镜、显微硬度仪和拉伸试验机对22MnB5钢激光焊接接头不同压下率下冷变形后接头进行检测。结果表明,随着冷轧压下率增加,塑性变形程度增加,焊缝宽度和硬度增加,激光焊缝显微组织为板条马氏体,焊接接头抗拉强度基本不变,22MnB5钢激光焊接接头具有良好的冷变形性,在冷轧压下率小于80%时,不会由于焊接接头和母材组织不匹配而出现断带等安全问题。

The weld joints of the 22MnB5 steel by laser welding which were cold-deformed under different reduction rates were examined by metallographic microscope,scanning electron microscope,microhardness tester and tensile testing machine.The examination results showed that with increasing of cold rolling reduction rate,the degree of plastic deformation,welding line width and hardness grew,while the microstructure in the welding line by laser welding was lath martensite and its tensile strength remained unchanged nearly.So the weld joints of the 22MnB5 steel had good cold deformation,suggesting that such problems as steel-strip-breaking due to the mismatching between the weld joints and the base materials would not occur as the cold rolling reduction rate was less than 80%.