Effects of cold working on corrosion resistance of Co-modified Ni–16Cr–15Mo alloy in hydrofluoric acid solution.

We examined the effects of cold working on the corrosion resistances of Ni–30Co–16Cr–15Mo and Ni–16Cr–15Mo in 5.2 M HF acid solution at 100 °C. After cold working, the Ni–30Co–16Cr–15Mo samples exhibited a more significant increase in hardness compared to Ni–16Cr–15Mo as well as a more localised microstructure that contained a greater number of planar slipping bands and mechanical twinning. Both alloys exhibited a decrease in corrosion resistance, with the decrease being much greater in the case of Ni–30Co–16Cr–15Mo. The difference in the corrosion resistances of the alloys was ascribable to the differences in their microstructures. [ABSTRACT FROM AUTHOR]