油气输送管道对接环焊缝缺陷检测分析

通过X射线检测、金相组织检测、扫描及能谱分析，对某油气输送管道对接环焊缝缺陷及形成原因进行了分析。结果表明，环焊接头中存在焊瘤、密集气孔、内凹（焊道未填满）、未熔合和夹渣缺陷，缺陷处易产生应力集中，成为裂纹源。建议在油气管道对接环焊缝焊接操作时，一要保证管口组对精度，以减小错边、侧壁未熔合的可能性，二要选择合适的焊接方法。

Detection Analysis of Oil and Gas Transportation Pipeline Butt Joint Circumferential Weld Defects

The detection and analysis on defects and forming reason of some oil and gas transportation pipeline eireumferential weht were eondueted through X-ray detection, metallographie analysis, scanning electron microscope （SEM） and energy spectrum analysis. The result showed that some defects existed in cireumfert~ntial welded joint, such as weld beading, porosity, indent （weld incompletely filled）, incomplete fusion and slag inclusion, stress concentration easily appear in defect, turn into crack source. It suggests in welding operation of oil and gas transportation pipeline circumferential weld, on the one hand, to guarantee assembly accuracy of pipe end to decrease the possibility of offset and incomplete fusion in side wall; on the other hand to choose suitable wehtiug method.