Effect of secondary carbides on oxidation wear of the Cr-Mo-V cast steels

The wear characteristics of the Cr-Mo-V cast steels with second phases were studied. Secondary carbides were found to have obvious influences on oxidation wear rate. Almost two orders of magnitude of variations for wear rates were created because of different secondary carbides, i.e. from 4.30 x 10(-15) m(3)/N m to 1.2313 x 10(-13) m(3)/N m. The easily-coarsen Mo6C precipitated along boundaries of grains and laths, leads to the transition from mild wear into severe wear. On the contrary, wear rate of oxidation wear is substantially reduced in the cast steels with stable, dispersed VC. These may be attributed to delarnination patterns of oxide layer. (c) 2007 Elsevier B.V. All rights reserved.