Case study: Cracking occurred in a (UNS S32100) type austenitic stainless steel nozzle fitting at a low point in the reactor effluent piping in a Gasoil Hydrotreater unit following start up. Normal preventive measures had been taken. The failed sample was removed for metallurgical analysis and determination of mechanism(s).
Cases where alkaline-carbonate stress corrosion cracking (ACSCC) occurred, including a cold wall Fluid Catalytic Cracking (FCC) Unit regenerator and a mercaptan oxidation unit. This paper discusses work done to monitor on-going ACSCC risks through sour water sampling, chemical analysis, and ionic modeling.
A failure in one of the de-salter relief lines of the crude distillation unit. This paper describes the probable causes and the adopted remedies for the localized corrosion observed in the insulated relief line. Circumstantial evidence and failure morphology were used in arriving at the root cause for this failure.
Coking is carbon deposition from a gas phase that is encountered in many reforming, cracking and other high temperature processes. An experimental high temperature coking atmosphere was constructed and used to evaluate the effects of temperature, time and metal surface roughness on the carbon deposition of an alumina forming alloy.