Optimizing the resistance of Ni-advanced weathering steel to marine atmospheric corrosion with the addition of Al or Mo

Self-designed Ni-advanced weathering steels alloyed with Al and Mo tested in simulated tropical marine atmospheric environment was investigated through microstructure characterization, rust analysis, and electrochemical methods. The results showed that the addition of Al and Mo in 1Ni steel (Ni content: 1 wt%) is beneficial to improve the corrosion resistance in longer time periods, and thicker protective rust layer can be formed on the steel surface when Mo is added than when Al is added. XPS analysis on the rust indicates that MoO2 and MoO3 can prevent the degradation of NiFe2O4, thereby maintaining an electronegative inner layer in the rust to resist Cl. The large-sized Al-enriched particles, which consist of AIOOH and Al(OH)(3), are unable to block the invasion of Cl, but the corrosion products with the same phase can fill in the pores and cracks, which makes the rust layer compact and increases the resistance of the rust layer. (C) 2021 Elsevier Ltd. All rights reserved.