Alloy-coated ferrous metal substrate

Claim 1

An alloy coated ferrous metal substrate, said ferrous metal substrate having a thermal conductivity relative to silver taken as 1 at substantially ambient temperature of at least about 0.06 calories/sq.cm./cm/° C/sec, said alloy coating being a fused flame sprayed, self-fluxing heat and corrosion resistant iron-group metal-base alloy metalurgically bonded to said ferrous meal substrate and having a thickness ranging from about 0.005 to 0.15 inch, said iron-group metal-base alloy consisting essentially of a total of about 5% to 30% by weight of a strong boride and carbide-forming solute metal selected from the group of refractory metals consisting of W, Mo and Cr, up to about 3% C, about 0.5% to 5% B, about 0.1% to 6% Si and the balance essentially said iron-group metal, the amount of boron and/or carbon present in said alloy being sufficient to combine with a substantial amount of said refractory metal when present to form secondary borides and/or secondary carbides, such as to provide a coating having a thermal conductivity at substantially ambient temperature relative to silver taken as 1 of at least about 0.05 calories/sq.cm/cm/° C/sec., said coating also containing 0 to 80% by weight of primary refractory carbides selected from the group consisting of carbides of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W based on the total coating.