Caustic Corrosion Resistance of RE-Ni-Cu Alloy Cast Iron

The corrosion rates of RE-Ni-Cu alloy cast irons in hot concentrated alkaline solution were measured by using dynamic condition hydrometer method; the microstructures and surface corrosion morphology of alloy cast irons were observed by means of the optical microscope and SEM; the composition was analyzed using XES. Experimental results showed that the corrosion resistance of the alloy cast iron with 0.05% RE is better, and its etched surface is flat with bigger area of matrix and less quantity of bellied carbide. The caustic corrosion of Re-Ni-Cu alloy cast irons is uniform corrosion, which mainly lies on the quantity, dimension and distribution of the graphite and carbide. The Ni and Cu enriched in the matrix are advantageous to the improvement of caustic corrosion resistances of that zone.