The Effect of Alloying Elements on Sea Water Corrosion of Steel (1st Report)

Laboratory Corrosion Teats

Abstract

Four types of laboratory corrosion tests involving total or intermittant immersion in artificial sea water or tap water were carried out in order to study the effect of alloying elements on sea water corrosion of Cu bearing steel. The alloy compositions of 32 test steels were designed with two levels' orthogonal array L₃₂ (2³¹), 9 variable factors of which were C, Si, Mn. P, Cu, Ni, Cr, Ti and Al contents. Regression analysis was applied to the test results. Mn, Ni, Ti and Al were found to have no effect on the corrosion. C was harmful, while Cr and P, and in some cases Cu and Si, were beneficial. Martensitic structure of 2% Cr steel was preferable to ferrite-pearlitic structure as far as corrosion resistance to intermittent immersion in artificial sea water was concerned. Cr content in matrix seemed to control the corrosion rate.