Surface metal welding process and apparatus

Claim 1

A method for alloying a material into at least a selected portion of the surface of a body of a base material wherein a part of the base material becomes a part of the alloy and wherein an alloy layer of substantially uniform depth and composition is formed on said selected portion of the surface of said body, comprising melting a selected continuous lateral expanse of the surface of said body onto which alloying material is introduced by establishing a plurality of arcs at current levels of from 300 to 10,000 amperes from non-consumable electrodes provided in arc devices which include a nozzle having an outlet passage, confining the arc in the nozzle, introducing gas through the nozzle and into the arc, the combination of said gas flow and said outlet passage nozzle diameter providing a directionally stable arc effluent, positioning said directionally stable arc effluents proximately to each other so that the magnetic field created around each of said arcs effects the arcs in immediate proximity therewith, energizing said arcs such that an AC voltage is applied at least to alternating arcs to produce said interacting magnetic fields among said multi arcs, spacing said nozzles from about 1/4 to about 1 nozzle outside diameter from the surfaces of said body such that the length of said arcs may be swept across said selected surface portion and, varying at least one of said arc current, said gas flow, and said arc length to control the sweep of said arcs, and moving said body and said plurality of electric arcs relative to one another in a direction from one end of the body to another to advance the molten zone of alloyed material to successive lateral expanses on said body, while allowing already molten lateral expanses to cool under conditions substantially uniform across the entire selected lateral expanse.

Claim 2

A method for alloying a material into at least a selected portion of the surface of a body of a base material wherein a part of the base material becomes a part of the alloy and wherein an alloy layer of substantially uniform depth and composition is formed on said selected portion of the surface of said body, comprising melting a selected continuous lateral expanse of the surface of said body onto which alloying material is introduced by establishing a plurality of arcs at current levels of from 300 to 10,000 amperes from non-consumable electrodes provided in arc devices which include a nozzle having an outlet passage, confining the arc in the nozzle, introducing gas through the nozzle and into the arc, the combination of said gas flow and said outlet passage nozzle diameter providing a directionally stable arc effluent, positioning said directionally stable arc effluents proximately to each other so that the magnetic field created around each of said arcs effects the arcs in immediate proximity therewith, energizing said arcs such that an AC voltage is applied at least to alternating arcs to produce said interacting magnetic fields among said multi arcs, spacing said nozzles from about 1/4 to about 1 nozzle outside diameter from the surfaces of said body such that the length of said arcs may be swept across said selected surface portion and, varying at least one of said arc current, said gas flow, and said arc length to control the sweep of said arcs, and moving said body and said plurality of electric arcs relative to one another in a direction from one end of the body to another to advance the molten zone of alloyed material to successive lateral expanses on said body, while allowing already molten lateral expanses to cool under conditions substantially uniform across the entire selected lateral expanse.