Effect of phase stability on the wear resistance of white cast iron at 800 °C

The high temperature oxidation tests of Ni-Cr alloys which containing different alloying elements such as Mo. W, B, Cr and Ni were carried out through placing the specimen in a muffle for 100 h at 800 degreesC. In order to determine the effect of oxidation on the wear behavior of the alloys at elevated temperature, an interrupted oxidation-abrasion wear test was carried out on a high temperature three-body abrasive wear tester. Then the oxide and wear surfaces of the specimens were examined and the effect of the alloying elements on the oxidation and wear properties was discussed. Combining the obtained results, the following aspects are obtained. The high temperature oxidation stability of the carbide of the alloys can be improved by adding alloying elements Mo, W and B. And the sufficient amount of alloying elements Cr and Ni in the alloys can raise the chemical stability of the matrix effectively. The controlling factors affecting the wear behavior are the oxidation stability of carbide and the oxidation synergistic performance of carbide with matrix. The excellent wear resistant performance of the carbide phase in alloy can be obtained only when the matrix phase support it effectively. Accordingly, the alloy still can't possess a good wear resistance when the oxidation synergistic performance of the carbide with matrix is poor, even the carbide oxidation stability is good. (C) 2002 Published by Elsevier Science B.V.