全位置焊接气瓶接头焊缝异常缺陷原因分析

增压气瓶是运载火箭箱体增压系统的重要组成部分，其与增压管系的焊接采用全位置焊接技术，采用带内衬O型环的焊接接头结构。在产品焊接过程中，气瓶接头与管系接头的全位置焊接焊缝中出现了焊接气孔超标的现象。对焊接气孔的形貌和分布特征进行分析，并通过能谱分析和红外光谱开展焊接气孔形成原因的分析，确定气瓶接头气密试验过程中的残留润滑脂多余物是导致焊接气孔缺陷的主要原因，并且通过气密试验和全位置焊接试验对焊接气孔进行复现，验证了焊接气孔形成原因的判断的准确性。根据焊接气孔的形成原因，通过绸布蘸取酒精溶剂进行反复擦洗，并增加一道内窥检查工序进行确认，可以有效防止焊接气孔的形成。

Cause Analysis of Abnormal Defects of Welding Joint of All Position Welding Vessel

Pressure vessels are an important part of the tank pressurization system of carrier rockets, welded with pressurization pipes using all position welding technology. The welding joint structure is the O-shape collar with inner bladder. In the process of welding, the number of welding blowholes at the welding joint of vessels and pressurized piping exceeds the standard requirement. The morphology and distribution characteristics of blowholes were analyzed, and the formation cause for the blowholes was analyzed by spectrum and infrared spectrum analysis. It is found that the residual grease reminders are the main cause for the blowholes. Recurrence of the blowholes was carried out by air tightness and all position welding testing to verify the judgment. According to the formation cause for the welding blowholes, some measures were taken to effectively prevent the formation of welding blowholes: repeatedly scrubbing with silk cloth filled with alcohol solvent and adding an endoscope inspection process.