Corrosion Behavior of Carbon Steel in Concentrated LiBr solutions up to 473K

Abstract

In view of demand for raising maximum operation temperature in commercial absorption refrigerator, the corrosion behavior of carbon steel in concentrated LiBr solutions was investigated as a function of LiBr concentration and temperature up to 473K. Carbon steel specimens were exposed in deaerated LiBr solutions for 200h and the changes in weight were measured. The amount of corrosion increased with temperature when the concentration of LiBr was higher than 17mol kg^-1, while it decreased slightly with temperature in 10mol kg^-1 LiBr solution. Lithium hydroxide (0.1mol kg^-1) decreased the amount of corrosion markedly when the LiBr concentration was lower than 10mol kg^-1 but it could not inhibit the corrosion at concentrations higher than 17mol kg^-1. Among several oxoacid salts tested in this study, molybdate ion worked most effectively as an inhibitor at 473K as well as at lower temperatures. A specimen oxidized in air at 673K almost sustained its passivity during exposure to 17mol kg^-1 LiBr+0.1mol kg^-1 LiOH solution at 473K.