DISCUSSION ON THE INTERFERENCE PHENOMENON OF MULTIPLE FAILURE MECHANISMS AND DETERMINATION OF DOMINANT FAILURE MECHANISM FOR PRESSURE EQUIPMENTS

For petrochemical pressure vessels subjected to complex media environment, the competition, inhibition, promotion and interference of multiple failure mechanisms have been discussed by several failure case analyses and experimental investigation. The main factors that influence formation of dominant failure mechanism are analyzed and the judgment principles of the dominant failure mechanism are raised in the case of interaction of multiple failure mechanisms. In this paper, relevant mechanisms are also discussed, e.g. intergranular corrosion and intergranular stress corrosion failure mechanisms of austenitic stainless steel, failure mechanisms of austenitic stainless steel when Cl- and alkaline environment exist concurrently and failure mechanism of austenitic stainless steel when medium such as Cl-, CO2, H2S, H2O, etc. exist concurrently.