Leakage Causes of Low Carbon Steel Pipeline in a Waste Heat Boiler and Recommendations for Improvement

A lot of cracks were found near the superheater housing of a cement waste heat boiler which caused serious steam leakage in the pipe and affected the generation efficiency. SEM and EDS results combined with the analysis of a large number of operation data indiciate that the cracking was caused by corrosion. The exceeding of hot alkali content in the steam was the main reason causing the stress corrosion of low carbon steel. Based on stress corrosion mechanism, a safety assessment for other parts was made and recommendations for improvement were proposed.