Method of manufacturing thin-walled corrosion resistant metallic objects
AssigneeMasco Corporation
InventorCharles R. Weir
Life of this patent
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Abstract
A method of manufacturing metallic objects having thin walls and comprised of corrosion resistant materials. The method has the consecutive steps of forming a workpiece in the shape of the desired end product from a metal having a low resistance to an etchant, forming within a surface of the workpiece a metallic alloy case resistant to the etchant and etching the workpiece with the etchant.
Claims31
A method of making a thin-walled corrosion resistant end product from a workpiece comprised of a starting metal not resistant to an etchant and from an alloying metal which is selectively soluble in said starting metal to produce an alloy metal impervious to said etchant, the method comprising the consecutive steps of forming said workpiece into the shape of said end product, forming an alloy case of said alloy metal on a surface of said workpiece, and exposing said workpiece to said etchant to remove the portion of said workpiece which is not alloyed.
A method of making a thin-walled corrosion resistant end product, the method comprising the consecutive steps of forming a low carbon steel workpiece into the shape of said end product, forming an acid resistant alloy case on a surface of said steel workpiece, and etching said workpiece with an acid which will dissolve the steel but to which the alloy case is impervious.
A method of continuously making thin-walled corrosion resistant tubing, the method comprising the simultaneous steps of supplying a portion of a continuous line of a metallic wire comprised of a starting metal to a plating station, continuously plating said portion of said wire in said plating station with an alloying metal, continuously feeding a portion of said wire from said plating station into a furnace, continuously heating said portion of said wire in said furnace at a temperature between the temperature at which said alloying material alloys with said starting metal and the melting temperature of said wire, maintaining said wire within said furnace until said alloying material has diffused into the surface of said wire to produce an alloy metal case of a predetermined depth;
- continuously feeding a portion of said wire from said furnace to a cutting station, intermittingly cutting said portion of said wire at said cutting station into predetermined lengths of wire, said method further comprising the step for each of said lengths of wire of etching said lengths of wire with an etchant to which said starting metal is not resistant but to which said alloy metal is resistant.
A method of producing a corrosion resistant end product having a plurality of parallel passageways therethrough from at least three elongated workpieces comprised of a first metal having a low resistance to acid, said method comprising the consecutive steps of:
- plating an alloying metal on the outer longitudinal surface of each of said workpieces;
- arranging said workpieces in an array wherein the longitudinal axis of the workpieces are parallel to each other and wherein each of said workpieces is in contact along its outer longitudinal surface with the outer longitudinal surface of at least one of the other workpieces;
- heating said array of workpieces in the presence of a protective atmosphere to a temperature above the temperature at which said alloying metal will diffuse into said first metal and below the melting temperature of said first metal;
- maintaining said array at said temperature until said diffusion of said alloying metal into said first metal has produced a boundary layer of an alloying metal having a predetermined thickness and until said portions of said outer surfaces of said adjacent workpieces have bonded together;
- maintaining said array in said protective atmosphere while cooling said array to a temperature at which the ambient atmosphere will no longer oxidize said alloying metal;
- and
- etching the remaining unalloyed portion of said first metal from said array with an etchant that will dissolve said first metal but will not dissolve said alloy metal.
Dependencies are inferred from the claim text.