E级钢焊接裂纹的产生原因及预防措施

Causes and Precaution Measures for Welding Crack of E Graded Steel

采用CO2+惰性气体保护焊的堆焊法,选用S136焊丝对试验母材(E级钢)进行焊接试验。利用光学显微镜、SEM对母材和堆焊层组织及裂纹断口进行了鉴定与分析。结果表明,堆焊层产生的裂纹为延迟裂纹,此裂纹产生的主要原因是焊接过程中的拘束应力过大。采取焊前预热的方法,选择合理的预热温度、焊后进行回火和缓冷能够避免裂纹的产生。

Using CO2＋ inert gas protection for surfacing welding, the experiment material （grade E steel） welding test using S136 welding wire was carried out. The microstmcture and fracture surface of hardfacing layer and matrix material were studied by optical microscope and SEM. The results show that, the hardfacing layer crack is delay crack, the main reason for the crack is the stress in welding process. The test results show that by taking before welding preheated method, choosing the reasonable preheating temperature, following after welding gentle cold, the appearance of crack can be avoided.