Research On The Metal Erosion-corrosion Base On A Failure Analysis About The Elbow

This paper is based on a failure analysis about an elbow of one coil heat exchanger, by the conventional failure analysis, the failure reasons that are related to the stress corrosion cracking and erosion-corrosion are obtained finally. The existed theories cannot explain this phenomenon clearly. To match the reality better, the CFD software are used to simulate the effect upon the corrosion that the temperature and pressure have on the heat exchange tube. Combined the simulate result and the actual situation of the equipment with the action oxidation theory ,a failure analysis is made. According to the action oxidation theory, the reason why the broken only happen at one special location and the reason why the stress corrosion crack appears can be explained. Drew the wear map though the corrosion date (Based on the corrosion data, a wear map is drawn) and the validity of the wear map is verified by the corrosion date from the other equipment. At last, provide the suggestions on the material selection, equipment design and equipment life prediction.