Hardfacing alloys of High Chromium White Irons (HCWI) were deposited on low carbon steel using Shielded Metal Arc Welding. Microstructure of HCWI consists of primary carbides, eutectic carbides and eutectic austenitic/martensitic matrix. This study investigated the corrosion behaviour of HCWI in both acid and neutral solutions. The corrosion behaviour of HCWI was evaluated using anodic polarisation technique. It was found that in acid solution at pH 1.5, corrosion occurs on eutectic austenite/martensitic matrix whereas at pH 2, the corrosion occurs on eutectic carbides. In the neutral environment at pH 7, corrosion of HCWI occurred in the eutectic austenite/martensite matrix in the presence of chloride ions, while in the buffered solution, corrosion occurred in the carbides. The results of this study show that the corrosion mechanism of HCWI for both acid and neutral environments was due to potential difference between carbides and eutectic austenite/martensitic matrix. The superimposed Pourbaix diagrams of chromium carbides with iron (Fe) and niobium carbide were useful in explaining the behaviour of HCWI in both acid and neutral solutions.
Kannoorpatti, K., & Marimuthu, V. (2016). Corrosion Behaviour of High Chromium White Iron Hardfacing Alloys in Acidic and Neutral Solutions. journal of bio- and tribo-corrosion, 2(4), 1-12. . https://doi.org/10.1007/s40735-016-0059-7