HARDNESS AND WEAR RESISTANCE OF (TIC,CR3C2)/STEEL SURFACE COMPOSITES FABRICATED BY HIGH-ENERGY ELECTRON-BEAM IRRADIATION

Abstract

The present study is concerned with the improvement of hardness and wear resistance in (TiC,Cr3C2)/carbon steel surface composites fabricated by high-energy electron beam irradiation. Three kinds of powder mixtures, i.e., 50TiC50MgF(2)(flux), 50Cr(3)C(2)-50MgF(2), 25TiC-25Cr(3)C(2)-50MgF(2) (Wt-%), were placed on a plain carbon steel substrate, which was then irradiated with electron beam. In the specimens fabricated with flux powders, the surface composite layer of 3.0 similar to 3.2 mm in thickness was successfully formed without defects, and contained a large amount (up to 10 vol.%) of TiC or Cr7C3 carbides in the matrix. The hardness and wear resistance of the surface composite layer were directly influenced by hard carbides, and thus were about five to ten times greater than those of the steel substrate. Particularly in the surface composite fabricated with TiC and Cr3C2 powders, the wear resistance was most excellent because the hardness of the carbide and martensitic matrix was very high.