Leaking of 316L stainless steel heat exchanger tubes in carbon dioxide process

This study covered a premature leaking of stainless steel 316L heat exchanger tubes. Leaking occurred in a cooling process of carbon dioxide gas mixture from 140 to 55°C. Several leaks were observed after short service life of 70 days. A systematic investigation of the rapid degradation was achieved through a multi-angle approach backed by comprehensive analytical techniques: including visual inspection, optical microscopy, SEM/EDS, and chemical analysis. In addition, valuable insights were obtained from the dew point modeling of condensed acids. The key finding and novelty of this study is the identification of the synergistic dew point corrosion by HCl and HF, and its role in tube damage. Recommendations for higher performance alloys were addressed as well. The insights and understanding presented in this work are believed to be of significant value for both academic and industrial readers.