Effect of chromium content on the corrosion resistance of ferritic stainless steels in sulfuric acid solution

Abstract

Due to recent increases in the price of Ni, steel use is currently undergoing a global shift from austenitic stainless steels to ferritic stainless steels. In this study, the corrosion behavior of four types ferritic stainless steels with different Cr contents was investigated to study the effect of Cr content on the corrosion resistance in a sulfuric acid solution. The polarization curves of the ferritic stainless steel with the highest Cr content indicated the best corrosion resistance. No corrosion was observed for the stainless steel with 24 mass% Cr after a potential sweep based on ex-situ SEM images. Corrosion resistivity was improved for high Cr content (>24 mass%) stainless steel because it is considered to form a stable passivation layer.

Keywords

• Materials science
• Electrochemistry
• Metallurgical engineering