Effect of Cr Content on Corrosion Law and Mechanism of Chloride-Resistance for Low Alloy Steel

The corrosion law of tanker steels with different Cr content in a simulated corrosion environment around cargo oil tank was investigated by soaking corrosion test, XRD analysis, scanning electron microscopy (SEM) and electrochemical test. The results indicated that the corrosion resistance of developed tanker steels was increased first and then decreased with increasing Cr content; the corrosion resistance of oil tanker steels was the best when the mass fraction of Cr was 0.06% and 0.012%. The mechanism by which Cr improves the corrosion resistance of tanker steel is to promote the generation of compact corrosion products on the steel surface and thus to reduce corrosion.