Influence of Alloying Element Addition and Heat Treatment on the Sand Erosion Resistance of Chromium White Iron

The influence of chemical composition, heat treatment and wear condition on the sand erosion resistance of high chromium cast iron was investigated systematically. The as cast and heat treated chromium cast iron containing 1.7 to 3.8&%C were prepared in which additives as 5 to 8%V, 4 to 6%Ni, 1 to 2% Mo and 0.2%Ti had been introduced. Sand erosion tests were carried out under the wear condition with flattery silica sand of 90 mesh 40 vol.% and water 60 vol.%. Wear of the cast irons proceeded from interphase corrosion between matrix and carbides and was followed by abrasive and corrosive wear of matrix. Weight loss of the cast irons decreased with an increase in chromium content in matrix. The sand erosion resistance of lower chromium irons was improved by quenching and tempering. V, Ni, Mo and Ti in the irons improved the wear resistance. The 1.69%C-12.2%Cr-4.77%V-0.92%Mo-0.2%Ti and 2.29%C-12.4%Cr-8.46%V-1.0%Mo-0.2%Ti cast irons containing granular eutectic vanadium carbides and fine granular secondary carbides were particularly superior in terms of sand erosion resistance even under more corrosive wear condition with flattery silica sand 40 vol.&% plus water 54 vol.% and sea water 6 vol.%.