Corrosion Cracking Analysis of 2Cr13Mn9Ni4 Stainless Steel Hoops

Many 2Cr13Mn9Ni4 stainless steel hoops cracked or fractured during service, which laid a great hidden danger for flight safety. By statistically analyzing the law of a large number of hoops, it was found that the fracture position and morphology were similar, so the corrosion cracking analysis of 2 Cr13Mn9Ni4 stainless steel hoops is of great significance for the safety application of hoops. Appearance observation was carried out on the fault parts; macroscopic and microscopic characteristics observation and energy spectrum analysis were carried out on the fracture of the fault parts; metallographic inspection and hardness test were carried out near the welding seams of the fault parts; intergranular corrosion test and thermal simulation test were conducted on the samples of the fault parts; and finally the stress of the hoops was simulated. The analysis results show that the hoop failure was caused by the coeffect of residual stress, environmental corrosion and intergranular sensitization due to welding.