Production of carbide-surfaced wear-resistant ferrous bodies

Claim 1

IN THE METHOD OF MAKING ARTICLES HAVING AN EXPOSED WEAR-RESISTANT SURFACE REGION CONSISTING ESSENTIALLY OF A METAL CARBIDE FORMING AN INTEGRAL PART OF SAID ARTICLE AND CONSTITUTING ONLY A SMALL FRACTION OF THE MASS OF SAID ARTICLE, THE PROCEDURE COMPRISING THE STEPS OF PROVIDING A FERROUS BODY HAVING A MECHANCIALLY WORKED SURFACE ON A PORTION THEREOF THAT IS AT LEAST 0.020 INCH THICK AND CONTAINING ADJACENT THE SURFACE THEREOF AT LEAST 0.4% OF AVAILABLE CARBON, REMOVING THE STRATUM OF WORK-AFFECTED FERROUS SURFACE PARTICLES FROM SAID SURFACE REGION, DEPOSITING AT AN ELEVATED TEMPERATURE, ON THE EXPOSED SURFACE REGION OF SAID BODY AT LEAST ONE METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM, COLUMBIUM, TANTALUM, MOLYBDENUM, AND TANGSTEN FROM A COMPOUND OF SAID METAL AND CAUSING THE DEPOSITED METAL TO REACT WITH AVAILABLE CARBON OF SAID SURFACE REGION TO PRODUCE OUT OF AN INTEGRAL SURFACE LAYER OF SAID SURFACE REGION OF SAID PARTICLE A METAL CARBIDE LAYER CONSISTING ESSENTIALLY OF A CARBIDE CONTAINING AND DEPOSITED METAL, AND CONTINUING SAID DEPOSITION OF SAID METAL AND THE CARBIDE FORMING REACTION OF THE SO DEPOSITED METAL WITH THE AVAILABLE CARBON OF SAID SURFACE REGION UNTIL AN INTEGRAL LAYER OF SAID METAL CARBIDE AT LEAST ABOUT 8 MICRONS THICK HAVING A SURFACE HARDNESS OF AT LEAST ABOUT 1500 VICKERS HARDNESS IS INTEGRALLY FORMED ON SAID SURFACE REGION.