海洋隔水管对接环焊缝接头高周疲劳性能研究

摘要

The four-point bend fatigue test method was used to measure the high cycle fatigue property of marine riser X80/X80J butt circumferential weld. The influence on crack initiation location of stress concentration,microstructure and hardness was analyzed comprehensively. The results showed that the fatigue crack of welded joint with weld reinforcement initiates from toes, and then extends to the heat affected zone from the weld reinforcement,while the crack initiates from weld and propagates along the weld without reinforcement. The stress concentration caused by the weld reinforcement is the main factor to reduce the welded joint fatigue performance. The fatigue limit of welded joint is 216 MPa for with reinforcement and 400 MPa for without the weld reinforcement.%采用四点弯曲疲劳试验法，测试了海洋隔水管道X80/X80J对接环焊缝高周疲劳性能。综合分析了应力集中、显微组织和硬度对裂纹萌生位置的影响。结果表明，有余高焊接接头疲劳裂纹在焊趾处萌生并向热影响区扩展，去除余高的焊接接头疲劳裂纹从焊缝处萌生并沿焊缝扩展；焊缝余高引起的应力集中是降低焊接接头疲劳性能的主要因素，有余高焊接接头的疲劳极限为216 MPa，去除余高的焊接接头疲劳极限为400 MPa。