High chromium white cast irons are multi component alloys that contain iron, carbon and chromium as major elements, and molybdemium, nickel, silicon and manganese either as alloying element or impurities introduced during the foundry process [3-4]. For high chromium cast iron with a Cr concentration of some 18-20 wt% (hypo-eutectic composition), solidification starts with the nucleation of dendritic primary austenite (γ), followed by the formation of γ +M7C3 eutectic. The growth mechanism of M7C3 carbide and its morphology have been well documented by several researchers [5, 6]. In application which involves metal to metal contact, a considerable degree of work hardening can occur. This can results in surface deformation even on a very local scale. In high chromium alloys in which the matrix is completely austenitic under these circumstances and where the level of impact is relatively modest, such alloys in as-cast condition will perform very well. It must be stressed that performance under these circumstance relies upon the work hardening feature and operational circumstances must be amenable to service deformation. This approach can only be taken when the impact forces involved are relatively modest. At higher levels of impact stress, a point is reached where excessive stress are built up within the component and eventually the materials strength is exceeded and the outcome is complete failure in a characteristic stress fracture mode [3]. It is therefore imperative, that where higher impact loading is encountered, it is important that a completely stable metallurgical structure is utilised. This is normally obtained by suitable heat treatment to a tempered martensitic structure containing a mixed microstructure with a minimum of residual austenite which is known to be responsible for spalling