海洋立管系统腐蚀挂片支架断裂失效分析

Fracture Failure Analysis of Retractable Corrosometer on Offshore Riser System

通过对海洋立管系统进行腐蚀因素分析、流型计算、理化分析,得出腐蚀挂片支架发生断裂原因。基于生成严重段塞流的判定准则,确定立管系统的流体流型,同时进行了流体腐蚀分析、宏观形貌分析、化学成分分析、金相分析。结果表明:该立管系统存在严重段塞流,流体介质中Cl-对腐蚀起到促进作用,但主要腐蚀原因是严重段塞流的周期性波动对生产设施产生巨大交变载荷,引起腐蚀挂片支架在交变应力的作用下发生断裂。

Through the analysis of corrosion factors,flow-type calculation and physical and chemical analysis of offshore riser system,the fracture reason of retractable corrosometer was obtained.Based on the judgment criterion of severe slugging,the fluid pattern was determined.At the same time,the fluid corrosion analysis,macroscopic morphology analysis,chemical composition analysis and metallographic analysis were carried out.The results show that there is severe slugging in the riser system,and Cl-in the fluid medium promotes the corrosion,but the main cause of corrosion is the periodic fluctuation of severe slugging causing huge alternating loads,which leads to retractable corrosometer fracture under alternating stress.