Reliability Study on Corrosion Cracking at the Root of Steam Generator Riser Tube
Through the analysis of corrosion morphology and flow field structure,the study was conducted on the causes of corrosion and cracking near the riser nozzle of a floating head heat exchanger in the petrochemical enterprise's steam generator.The operational reliability of the pressure vessel was analyzed through strength verification and failure pressure calculation.The impact corrosion of two-phase flow is the main reason for the formation of corrosion and cracking defects;The decrease in corrosion resistance of welds caused by excessive welding heat input has a significant impact on corrosion and cracking.After calculation,the failure pressure of the cylinder is 1.58 MPa;The strength verification results indicate that the heat exchanger no longer meets the conditions for safe operation under the design pressure.For heat exchangers with phase change heat transfer and no steam water interface,using a bottom in and top out structure as the heat source medium can weaken two-phase flow corrosion.
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