Failure Cause Analysis and Solution of 316L Stainless Steel Material in a Petrochemical Equipment
After an emergency shutdown,material analysis,metallographic inspection and other physical and chemical inspection were carried out on the 316L material at the failure site.Combined with the results of ion chromatography analysis of corrosion products and process conditions,the analysis showed that the pitting corrosion of 316L stainless steel material was caused by the deposition and concentration of chloride ions in the stagnant area when mixed with the process flow.Where there is tensile stress,there are stress corrosion cracking cracks,pitting perforation and crack penetration will lead to leakage.In order to enable the device to start operation as soon as possible,through the analysis of equipment materials and service environment,it was decided to use hyperplastic polymer coating to protect the chloride ion deposition area on the inner surface of the equipment.After about 3 years of periodic observation after completion,the coating was intact and no corrosion occurred in the protection area.It is proved that 316L material coated with hyperbranched polymer coating is a timely and effective method to protect against chloride ion corrosion.
NETL
NSTL
万方数据
