Integral effects of Ca and Sb on the corrosion resistance for the high strength low alloy steel in the tropical marine environment.

The integral effects of Ca and Sb on the corrosion properties of E690 steel were studied in a simulated tropical marine environment through immersion and dry/wet cyclic tests, focusing on localized and long-term corrosion properties. Results showed that Ca improved the corrosion resistance of steel by modifying the MnS inclusion into MnS-CaAl 2 O 4 inclusion, and Sb enhanced the consumption of H+ to decrease the electrochemical activity on steel surface. The protectiveness of the rust layer was increased by the enrichment of Ca and Sb, and the alkalization caused by Sb promoted appositional enrichment of Sb and Ca in the rust layer. • Ca inhibited the dissolution process of inclusions and reduced the susceptibility of pitting corrosion. • Sb can consume H+ to promote the formation of Ca(OH) 2 in the rust layer. • The enrichment of Ca and Sb in the rust layer promoted the α/γ, and enhanced the protective properties of the rust layer. [ABSTRACT FROM AUTHOR]