Erosion–corrosion of various oil-refining materials in naphthenic acid

A jet-impingement installation for high-temperature and fast-flow simulation of oil-refining environments has been designed and established. The optimum experimental parameters have been selected by considering both the numerical analysis results of the jet-impingement flow field and the practical aspects of system operation. The naphthenic acid erosion–corrosion (NAEC) resistance of carbon steel (CS), pack-aluminized carbon steel (AS) and molybdenum (Mo)-bearing stainless steels (SSs) were evaluated. It was found that increasing the fluid velocity and/or increasing the experimental temperature significantly aggravated NAEC, which may be attributed to the enhanced mass transfer and the accelerated corrosion reactions at surface active sites as well as the rapid spallation of corrosion products from the metal surface. Both the aluminized carbon steel and the stainless steels showed much better resistance against NAEC than the carbon steel. The NAEC resistance of the stainless steels increases with increasing molybdenum content. The possible reasons for the observed NAEC behavior are discussed.