| Title |
Effects of Alloy Elements Cr, Co and W on the Corrosion Behavior of Low Carbon Steel in Synthetic Seawater |
| Authors |
심재주(Sim Jae Ju); 유승재(Yu Seung Jae); 최윤석(Choe Yun Seog); 김정구(Kim Jeong Gu); 유장용(Yu Jang Yong) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Alloying element; Carbon steel; Seawater; EIS; Aqueous environments; Rust layer; Corrosion behavior |
| Abstract |
The aqueous corrosion characteristics of 1% Cr-steel alloyed with small amounts of Co and W, in synthetic seawater was studied by using immersion weight-loss tests, electrochemical corrosion tests (potentiodynamic test and electrochemical impedance spectroscopy (EIS) measurements) and analytical techniques. 1% Cr steels containing Co or W from 0.2 to 0.4 wt.% showed higher corrosion resistance than the 1% Cr steel in the immersion and potentiodynamic tests. EIS measurements showed that the Nyquist plot presented one time constant. Furthermore, the Co- and W-bearing steels present higher Rp values than the 1% Cr steel through all the test period. The better corrosion resistance of the Co-and W-bearing steels is attributed to protectiveness of the surface layer. The corrosion products were examined using electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS). The results of EPMA indicated that Cr was concentrated in the inner region of the rust layer, while Co and W were distributed all over the rust layer. XPS results showed that Co existed as a trivalent oxide in the rust layer and W in the rust appeared in the form of a WO₄ compound. |