Particulate-TiC-hardened steel surfaces by laser melt injection

Hardened surfaces were produced on 304 stainless steel by the recently developed process of injecting carbide particles into a shallow laser-melted surface layer. The injected TiC can alter the surface properties in two different ways. With processing conditions chosen to minimize the dissolution of the particles, the surface layer consists of the hard relatively coarse (a cross section of the order of 100 μm) injected particles in a soft matrix. With processing conditions chosen to promote the dissolution of the injected TiC, fine (a cross section of the order of 1 μm) dendritic carbides formed on cooling contribute to the hardening of the surface.