Leakage Analysis of a High Pressure Cylinder

A high pressure cylinder leaked in testing process. The macro morphology, chemical composition, metallographic structure, hardness and fracture of the leaking cylinder were analyzed. The results show that many inclusions in the cylinder material reduced the stress-corrosion resistance of the material. High inner pressure caused high tensile stress on the cylinder surface, chloride ions remained and accumulated at the top of the cylinder because of bare hand touching and follow-up low-temperature testing. Stress corrosion cracking happened on the cylinder due to the above reasons and resulted in the leakage of the high pressure cylinder finally.