Unraveling the effect of chloride ion on the corrosion product film of Cr-Ni-containing steel in tropical marine atmospheric environment

The effect of Cl- concentration on the corrosion behavior of Cr-containing steel in tropical marine atmospheric environment is systematically studied. Cl- ions affect the adsorption amount of water film and then affected O2 diffusion. They reduce the generation of NiFeO4 and Cr(OH)3 and destroy the electronegativity of inner film, further weakening the homologous enrichment of Ni, Mo and Cr and intensifying the penetration of Cl- ions. The amount of NiO and Cr2O3 decreases due to oxygen reduction, which reducrs FeOOH nucleation sites and promotes the large-size FeOOH generation, leading to increase the pores in the corrosion product films.

Automated summary

The effect of Cl- concentration on the corrosion behavior of Cr-containing steel in a tropical marine atmospheric environment has been investigated. Cl- ions influence the adsorption of water film and O2 diffusion. They reduce the formation of NiFeO4 and Cr(OH)3, disrupt the electronegativity of the inner film, weaken the enrichment of Ni, Mo, and Cr, and intensify the penetration of Cl- ions. The reduction in the amount of NiO and Cr2O3, due to oxygen reduction, decreases FeOOH nucleation sites, leading to increased pore formation in the corrosion product films.