Abstract: According to different causes, austenitic stainless steel weld cracks are classified into many types. In recent years, 300 series austeni-tic stainless steel TP347 materials are commonly used in reactor tubes and high temperature, high pressure and hydrogen pipelines for hydrogenation units. However, the quality problems of TP347 welding cracks and reheat cracks in engineering are very common. This paper analyzes the principles of a type of TP347 material welding crack in the process of welding on the spot through an engineering example. Then it finds the solution.

Key words: hydrogenation unit, TP347, chemical composition, mechanical properties, post-welding heat treatment, welding crack