Reasons Analysis on Leakage of TP304 Stainless Steel Heat Exchanger Tubes of a Heater

The leakage reasons of TP304 stainless steel heat exchanger tubes of a heater were analyzed by means of macroscopic examination, chemical compositions analysis, metallographic examination, SEM and EDS analysis. The results show that there were sulfur and chlorine elements accumulation at the leakage position, and there was deformation-induced martensite in the microstructure, which led the mechanical properties of the tube to exceed standard requirement highly and stress corrosion cracking to happen at the tube outer surface, and the cracks expanded continuously and finally resulted in leakage. So the main reason for the leakage was that the solid solution treatment of the heat exchanger tubes was insufficient and the medium outside the tube did not meet the requirement of the water quality.