Effect of rare earth addition on corrosion sensitivity of GCr15 bearing steel in marine environment

Abstract

Recent study demonstrates that only under very low-oxygen conditions can rare earth (RE) play a vital role in improving the performance of RE steels. In this work, the effect of RE addition on marine corrosion of the low-oxygen GCr15 bearing steel has been investigated with the involved mechanisms having been explored. The results indicate that the low-oxygen GCr15 bearing steel exhibits rather low sensitivity to marine corrosion, and the substantially decreased number and size in the inclusions modified by RE addition are responsible for the remarkable performance of the steel. Besides, RE addition has no obvious impact on the structure of GCr15 bearing steel, and the corrosion pits initiate and proceed following the galvanic corrosion mechanism.