2022 Volume 62 Issue 9 Pages 1887-1895
The corrosion resistance of slag-free self-shielded flux-cored welding overlays with different ferrotitanium (Fe–Ti) additions in 3.5 wt.% NaCl + 0.01 mol/L HCl acidic solution was investigated. The corrosion occurs in the matrix rather than M7(C, B)3, M3(C, B) and TiC in the microstructure of all the welding overlays. The corrosion resistance of hypereutectic welding overlay is decreased when the Fe–Ti addition is increased from 0 wt.% to 12 wt.%. The corrosion resistance of the welding overlay is the lowest since the overlay is a eutectic structure at the Fe–Ti addition of 12 wt.%. The eutectic structure increases the interface of corrosion reaction, which accelerates the corrosion rate and increases the corrosion current. With the Fe–Ti addition increasing from 12 wt.% to 24 wt.%, the corrosion resistance of the welding overlays with hypoeutectic structure is gradually increased, owing to the increase of the proportion of TiC and chromium content in the matrix.