Comparison of the aggressiveness of hydrogen sulfide media to steel in the vapor and water phases

Abstract

Corrosion resistance in hydrogen sulfide-containing environments of the main structural steels used in infrastructure facilities of gas fields has been studied. Gas objects are distinguished by the fact that most of the internal space of equipment and pipelines is in contact with the vapor phase, the internal corrosion of which under hydrogen sulfide conditions has been little studied. The corrosion rates and the composition of the formed corrosion products, which differ depending on the type of medium (water or steam), are determined. The phase composition (crystalline or X-ray amorphous) of the resulting products affects their protective ability and differs in the vapor and aqueous phases. It has been established that under gaseous conditions of moisture condensation, local pitting lesions are formed under fragile corrosion products. The thickness of the iron sulfide film in the vapor phase turned out to be lower than in the aqueous medium. It was revealed that dangerous corrosion consequences (in the form of blisters and cracking) appear on the studied samples of carbon and low-alloy steels, which are characteristic of the process of hydrogenation under conditions of hydrogen sulfide corrosion.