| Corrosive wear is one of the three main failure modes of materials. It is often found in the equipment used in the metallurgical machine, petrochemical industry, energy sources and transportation, and hydropower etc. The removal of materials caused by corrosive wear is great and results in a great deal of loss for national economy. Low chromium white cast iron as grinding ball material has been achieved a good effect in mineral processing and building materials industry due to their good wear resistance and lower price, which has an optimistic application. However, there is corrosive effect from liquid medium besides abrasive wear in application of mine wet ball mill, from which material wear is more severe than it from dry wearing. Therefore, there is very important theoretical significance and practical value to study the corrosive wear process and mechanism of low chromium white cast iron under wet wearing conditions.The corrosion-wear resistance of low chromium cast iron in different pH values was studied under simulation conditions by interaction theories between corrosion and wear with tank-type corrosion wear test machine made by ourselves. The results showed that the corrosion behavior is mainly oxygen-consuming corrosion of chromium cast iron under slurry corrosion medium and the effect of stirring and erosion in tank-type corrosion wear test machine with different pH values. However, it has a little hydrogen evolution in weak acid medium. The corrosive wear from stirring slurry mainly displays as turbulence effect. And quartz sand particles have great mechanical impact on specimen surface under turbulence effect, which provides large quantity of air to the solution and promotes electrochemical corrosion course of samples.The corrosion-wear resistance and corrosive wear mechanism of low chromium white cast iron with alloying elements Cu, Ni, Si, and Mn etc in slurry medium at pH 5,7 and 10 were analyzed by applied potential accelerated corrosion method. The results showed that under weak acid condition the low chromium white cast iron with 0.58% Cu possesses the best corrosion-wear resistance because the protective film at surface generated from the combined action of 0.58%Cu and proper amount Cr could prevent the corrosion process in corrosive wear. Then specimens with 0.67%Cu and 0.66% Ni have the best corrosion-wear resistance in neutral or alkaline medium. The increasing of content of Si and Mn has little effect on the improvement of corrosion-wear resistance, however, which can reduce corrosion-wear resistance of specimens under neutral medium. The corrosive wear of low chromium cast iron mainly is the process of corrosion and exfoliation. The microcrack will form in the initial stage and then extent to ferrite matrix, which lead to spalling of low chromium cast iron surface under the effect of etching solution and abrasive. |
