Dependence of the rate of corrosion and hydrogen diffusion of 09Mn2Si steel on the concentration of hydrogen sulphide in chloride-acetate environments

Abstract

It is found that with increasing concentration of hydrogen sulphide (H2S) to 100, 1000 and 2800 mg/dm3 (H2Ssat) the corrosion rate (C) of steel 09Mn2Si increases by ~1,48; 1,58 and ~1,64 times in 24 hours of exposure, however, in 720 h, it increases by ~1,8 and ~3,3 times at its concentration of 1000 mg/dm3 and saturation, while at 100 mg/dm3 C decreases by 1,8 times, which is due to the formation of continuous sulphide films. It is shown that the volume amount of hydrogen in 09Mn2Si steel increases with the increase of H2S content of the solution from 100; 500; 1500 and 2800 mg/dm3 in 1,2; 1,5; 1,9 and 2,5 times. Hydrogen diffusion increases from 0.9·10-6 to 2.7·10-6 cm2/s with the increase of membrane thickness from 0,75 to 1,50 mm and does not depend on the H2S content.