Metal dusting corrosion of carbon steel

Abstract

The kinetics and mechanism of metal dusting corrosion of carbon steel have been studied as a function of temperature (873-1173 K) in propanebutane atmosphere, being the mixture of 70 vol. % of propane and 30 vol. % of butane with the total pressure equal 105 Pa. The kinetics of corrosion have been studied thermogravimetrically in the apparatus enabling the mass changes of corroded sample to be followed continuously with the accuracy of the order of 10-6 g. It has been found that metal dusting corrosion in this atmosphere, modeling in some way industrial environments in petrochemical industry, proceeds with extremely high rate in agreement with linear rate law. Linear course of corrosion indicates that chemical reactions and not diffusion determine the overall rate of steel degradation. The aggregates of porous reaction products are composed with carbon filaments of various shapes, often separated by thin iron-containing particles. This peculiar shape of reaction products may be considered as characteristic feature of metal dusting corrosion in propane-butane atmosphere.