高温焊接对焊接接头组织和力学性能的影响

Effect of high temperature welding on microstructure and mechanical property of welded joint

通过对304不锈钢焊接试板预热到550,650,750℃,并保持焊件各部位的温度梯度为零或最小条件下分别进行焊接。结果表明:高温焊接使焊接接头的金相组织发生变化,经高温处理焊缝区域出现很多混杂的金相组织,混杂的金相组织具有良好的辅助性能,提高了材料的综合力学性能;高温焊接条件下试样的抗疲劳断裂强度随焊接温度的增加而增强。

By preheating 304 stainless steel welding sample to 550,650 and 750℃,and keeping the temperature gradient of each part of the welding part zero or minimum,welding was conducted respectively.The results showed that the metallographic structure of welded joint was changed by high temperature welding.After high temperature treatment,there were many mixed metallographic structures in the weld area.The mixed metallographic structures had good auxiliary properties,which could improve the comprehensive mechanical properties of the material.The fatigue fracture strength of the sample under high temperature welding condition increased with the increase of welding temperature.