Alloy coated metal base substrates, such as coated ferrous metal plates

摘要

A method is provided for applying a self-fluxing, self-bonding alloy coating of a hard facing alloy in powder form to a ferrous metal plate or substrate of melting point substantially higher than that of the hard facing alloy. The method comprises providing a plate of a ferrous metal substrate to be coated in which a surface of the plate to be coated is cleaned, e.g., by grit blasting. A retaining bank is formed substantially about a predetermined periphery of the plate by forming a ridge of a predetermined height on the clean surface to provide a confining zone into which a powder of the hard facing alloy is smoothly applied to a predetermined thickness to provide a composite of the alloy powder and the substrate. The powder may have an average particle size ranging from about 40 mesh to about 400 mesh (U.S. Standard) e.g., about 80 mesh to about 325 mesh. Following the application of the alloy powder to the confining zone to provide a composite, the composite is heated under substantially non-oxidizing conditions at a temperature sufficiently high to melt the alloy powder but below the melting temperature of the metal substrate, and thereby provide a dense alloy coating bonded to the ferrous metal plate or substrate. The coated plate is then cooled under substantially non-oxidizing conditions to solidify the coating.