An experimental investigation for corrosion resistance of stainless clad steel plate

This paper explores the corrosion resistance of stainless steel clad carbon steel plate (SCSP) in simulated marine environments. The hot-rolled steel plate, composed of stainless steel (304) exteriors and a carbon steel (Q235) core, underwent a salt spray test for 24 to 1344 h. The study focused on three sections: the transverse section, the core layer of carbon steel, and the outer layer of stainless steel. Using mass loss method, electrochemical methods, and microscopic and compositional analysis, it was found that stainless steel showed significantly better corrosion resistance than carbon steel. The carbon steel's corrosion rate was initially high but stabilized over time due to α-FeOOH in the rust layer. The transverse section exhibited a similar but slightly higher corrosion rate. XRD analysis identified α-FeOOH in the rust layer, while SEM, EDS, and 3D scanning indicated significant galvanic corrosion at the stainless and carbon steel interface, causing deep pits. Overall, the corrosion rate of the transverse section over longer exposure is influenced by both the rust layer's resistance and the galvanic corrosion at the bi-metallic section.