Comparative Analysis of the Effect of Pipeline Steel Microstructure on Internal Corrosion during Gas Transportation

The influence of microstructural features of five samples of 09Mn2Si pipeline steel on the formation of local defects during gas pipeline operation was analyzed. The chemical composition of the steels, their microstructure, and the properties of the corrosion products formed were examined. The applied methodological approach enabled determination of the composition, size, and degree of substitution in the siderite precipitate formed under isomorphic substitution. Tests using cyclic moisture exposure revealed the effect of pronounced banding on the formation of corrosion products. Tests under condensation conditions confirmed that the steel samples under study are susceptible to local carbon dioxide corrosion.