T型焊接接头的浅表层缺陷研究

Study on Shallow Surface Defects of T-type Welded Joints

通过对某T型焊接接头的浅表层缺陷调研,分析了该接头在各工艺阶段(焊接态、退火态、打磨态和喷丸态)的表面状态。结果表明:该缺陷为打磨和喷丸过程中形成的毛刺和闭合的氧化膜夹杂,工艺不合理是缺陷形成的主要原因。手动打磨平直表面时,氧化膜和夹杂可以被完全去除,然而在打磨T型接头焊缝表面时,因为空间位置狭小,局部位置氧化皮无法被清理干净,部分在喷丸时被打入到基体中形成闭合的氧化膜夹杂,部分以毛刺的形式残留在表面。根据分析结果,提出了采用交叉打磨的方式,并在打磨后采用长时间喷丸来改善浅表层缺陷。

Through the investigation of shallow surface defects of a T-type welded joint,the surface state of the joint in each process stage(welding state,annealing state,grinding state and shot peening state)was analyzed.The results show that the defects are burrs and closed oxide inclusion formed during grinding and shot peening.The main reason of the defects is unreasonable process.When the flat surface is manually polished,the oxide film and inclusions can be completely removed.However,the oxide scale in local position can not be cleaned due to narrow space during grinding of the weld surface of T-joint.Some of the oxide scale is injected into the matrix to form closed oxide inclusion during shot peening,and some remains on the surface in the form of burr.According to the results,the cross grinding method was proposed and the long shot peening after grinding was used to improve the shallow surface defects.