Abstract: TP347 is widely used in high pressure pipelines of residue hydrogenation, wax oil hydrogenation and hydrocracking units in petrochemical industry. However, in recent years, reheat cracks have appeared in the stabilization heat treatment of thick wall TP347 pipelines in many projects. Therefore, combining with the actual engineering case, this paper formulated the research scheme aiming at the T347 reheat crack with the weldability of TP347 material as the starting point. Through the residual stress detection, four point bending, intergranular corrosion, micro metallography and other series of experimental research, the paper determined the main influencing factors of reheat crack after stabilization heat treatment. According to the research conclusions and construction site conditions, it put forward the specific preventive measures to avoid cracks of stainless steel pipe after TP347 stabilization heat treatment.

Key words: TP347 pipeline, reheat cracking, experimental research, preventive measures