Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
  • B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
  • B23K35/0211—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in cutting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K7/00—Cutting, scarfing, or desurfacing by applying flames
  • B23K7/08—Cutting, scarfing, or desurfacing by applying flames by applying additional compounds or means favouring the cutting, scarfing, or desurfacing procedure

Definitions

• the present invention relates to a novel process for thermochemically removing material from metal or alloy bodies which are resistant or immune to such removal by the conventional procedure of impinging only flame and an oxygen jet against the surface to remove material therefrom, and additionally, relates to a novel adjuvant powder composition useful in the novel process.
• Certain metal and alloy bodies are immune or resistant to the thermochemical removal of material therefrom by the action of preheating flames and a stream or jet of oxygen.
• oxidation resistant bodies are certain ferrous metals, such as stainless steel and cast iron, certain non-ferrous metals, such as copper, aluminum and nickel, and many corrosion and oxidation resistant alloys, such as nickel-base alloys containing molybdenum, nickel-base alloys containing molybdenum and chromium, cobalt-chromium-tungsten alloys, and various siliconbronzes.
• Such metals and alloys which are immune or resistant to material removal by the conventional thermochemical metal-removing action of preheating flames and a stream or jet of oxygen are hereinafter referred to as refractory bodies.
• a process has been proposed for removing material from such refractory bodies by employing a heating flame and a finely-divided combustible adjuvant material-carrying oxygen stream distinct from but flowing along side of the flame.
• a heating flame and a finely-divided combustible adjuvant material-carrying oxygen stream distinct from but flowing along side of the flame.
• the finely-divided adjuvant material is burned in the oxygen stream to provide the additional heat necessary to bring the surface of the refractory body to a temperature at which thermochemical removal of material is accomplished by the oxygen stream, and additionally, to form composition products which flux the refractory metallic oxide and provide a removable fluid mixture of oxides.
• the adjuvant powder material employed in accordance with such process consisted mainly of iron, the'balance containing incidental impurity materials.
• thermochemical removal of material from refractory bodies While such process provided the first effective method for thermochemical removal of material from refractory bodies, it required the use of costly iron powder and'relatively low processing speeds, as compared to those encountered in the thermochemical removal of metal by conventional processes employing preheating flames and a stream or jet of oxygen alone.
• a process for powder cutting and scarfing refractory bodies which comprises, heating a portion of the body with an oxy-fuel flame, and concurrently directing against the heated portion of the body a stream of oxidizing gas and a stream of adjuvant powdered mixture containing between 10 and percent by weight quartz-containing material.
• the remainder may contain metallic iron, metallic aluminum, and/or other oxidizable metallic powders.
• material is thermochemically removed from the refractory body by applying an oxidizing gas jet against a heated zone of action on the surface of the body while concurrently flowing a stream of finelydivided adjuvant material, composed principally of quartzcontaining material, such as quartz, sand, rock crystal and the like, and oxidizable metallic powders, such as iron, aluminum, and the like, or mixtures thereof, into the zone of action so as to oxidize the oxidizable constituents of the body and produce reaction products sufliciently fluid to be expelled by the force of the oxidizing gas jet and the abrasive action and force of the adjuvant material stream.
• quartzcontaining material such as quartz, sand, rock crystal and the like
• oxidizable metallic powders such as iron, aluminum, and the like, or mixtures thereof
• the elemental metallic powder component or components of the adjuvant powder mixture burn readily in oxygen to liberate intense heat and form compounds which aid in fluxing the refractory oxides.
• the quartzcontaining component of the adjuvant material also aids in fluxing the refractory oxides, and additionally, serves to remove slag by an abrasive action.
• the use of the novel adjuvant powder mixture of the process of the invention produces thermochemical material removal from refractory bodies in which a very rapid removal of slag from the heat-effected zone is possible, thereby minimizing the extent of the heat effected zone. This result is accomplished without lowering the cutting speeds below values heretofore obtainable, and while at the same time employing a much less expensive powdered mixture.
• the process of the present invention may be employed for cutting and scarfing refractory bodies, and such procedures generically include operations known to the art as: severing, deseaming, surface conditioning, gouging,
• Successive portions of the refractory body on a path extending along a surface can be thermochemically removed by effecting a steady and continuous relative movement of travel between the body and the streams of oxygen and adjuvant material across the heated surface.
• Heating of the zone of action is accomplished by oxyfuel flames, preferably oxy-acetylene flames.
• a sufficiently fluid reaction product is one which can be blown ahead of the reaction zone by the oxygen and adjuvant material streams to expose a fresh material surface to the streams, and to preheat the surface portion to be removed next.
• sufficiently fluid reaction products are those which can be blown through and out of the kerf, thus exposing fresh material surfaces against which the jets impinge.
• Flame machining to remove surface material is carried out by advancing along the surface in the direction of a gas flow a low velocity oxygen jet directed obliquely at a small angle against successive heated zones on the surface of the body, while introducing the novel finelydivided material into the successive zones.
• heating is preferably accomplished by applying one or more oxy-acetylene flames to the surface.
• the oxygen jet velocity generally is maintained less than 980 ft./sec. (the acoustic velocity in oxygen) as it leaves the blowpipe nozzle.
• a high velocity oxygen jet preferably flowing at or above the acoustic velocity is directed at a large angle, such as 90, against the hot refractory body, while continuously introducing the finely-divided adjuvant material into the reaction zone where the oxygen impinges.
• the oxygen jet passes completely through the body and forms a deep kerf which is advanced along a selected path by steadily advancing the oxygen jet so as to im-. pinge against successive heated zones of the body. If a kerf extending only partly through the body is desired, the jet is advanced at a rate rapid enough to prevent complete penetration.
• Apparatus such as disclosed in U. S. Patents 2,451,422 to R. L. Wagner or 2,626,880 to E. Mcincke may be suitably employed for performing the process of this invention in a refractory body cutting application, whereas apparatus such as disclosed in U. S. Patent 2,622,048 to F. Moesinger may be suitably employed for performing the process of the invention in a refractory body scarfing application.
• the novel finely-divided adjuvant material is carried into the reaction zone in close association with the metal-removing oxidizing gas itself.
• the adjuvant material may be added to and carried by the stream of oxidizing gas in the blowpipe apparatus, in the manner described in U. S. Patent 2,451,422, or may be concurrently introduced into the reaction zone as a stream separate from the oxidizing gas stream, intermixing of the two streams being effected in the region of the reaction zone, in the manner disclosed in U. S. Patent 2,626,880. It has been found that the latter procedure is preferable since it does not introduce the problem of erosion of the oxidizing gas passages in the blowpipe, which effect is encountered where the oxidizing gas stream is employed as a carrier for the adjuvant powder stream.
• quartz-containing sands as well as substantially pure quartz have been employed successfully in the process of the present invention.
• Cowbay sand, quartz, and silica foundry sand have been found to possess excellent flow characteristics and produce excellent cut and scarfed surface qualities.
• the particle size of the particulate components of the adjuvant powder mixture is important to the quality of the cut as well as to the flow characteristics encountered in the handling of the stream of adjuvant material. Quartz-containing materials of fine particle size do not produce the most desirable results in either cutting or scarfing operations, since, while they do provide good starts, they do not allow deep penetration of the refractory body. Quartz-containing materials of coarse particle sizes permit full-cut penetration but do not provide good starts.
• a quartz-containing material particle sizes substantially distributed over the range of from about 30 to 100 mesh may be employed in the method of the invention in either powder cutting or scarfing applications to produce good starts with good penetration. It is believed that the need for relatively large size particles of quartz-containing material in the adjuvant material mixture indicates that, in cutting, an erosive action is responsible for the effectiveness of this constituent of the adjuvant powder material. It has been found, in keeping with this belief, that a standard quartz-containing material particle sizes such that 100 percent passed through 30 mesh, percent held on 60 mesh (i. e.30, 90% +60) produced the best cutting results.
• the particle size of the iron and/ or aluminum or other oxidizable metal powder constituent of the flowable adjuvant powder mixture of the invention also effects the quality of the cut and speeds obtainable in the operation of the process of the invention.
• iron powder particles sized between 30 and 200 mesh give good penetration but poor starts; iron powder particles sized between 200 and 325 mesh started satisfactorily and produced satisfactory material removal but required powder flow and pressure conditions which were rather critical.
• Iron powder particles sized finer than 325 mesh give good starts, but provide poor cut penetration in the process.
• Such powders are hereinafter referred to as standard powders.
• the iron is likely present as iron oxide.
• thermochemical refractory body cutting and scarfing adjuvant powder mixture may be employed.
• the powder mixture contains a mixture of quartz-containing powders and oxidizable metal powders and is to be stored for long periods of time before use or transported to the point of use, undesirable segregation of the constituents of the mixture may be encountered.
• a bonding agent may beemployed in small quantities to prevent segregation.
• Mineral oils, vegetable oils and, in fact, any sticky non-reactive material may be employed to bond the powder mixture to eliminate segregation.
• a sand-iron powder mixture (30, 90% +60 mesh sand and standard iron powder) was bonded with one part of SAE-ZO motor oil to 450 parts by weight of the mixture.
• SAE-ZO motor oil was bonded with one part of SAE-ZO motor oil to 450 parts by weight of the mixture.
• a flowable thermochemical refractory body cutting and scarfing adjuvant powder mixture containing between 10 and 80 percent by weight abrasive material predominantly containing quartz and having particle sizes substantially distributed between about and 100 mesh and the remainder at least one oxidizable metal powder selected from the group consisting of iron powder and aluminum powder.
• a flowable thermochemical refractory body cutting and scarfing adjuvant powder mixture consisting essentially of between 10 and 80 percent by weight abrasive material predominantly containing quartz and having particle sizes substantially distributed between about 30 and 100 mesh, and the remainder at least one oxidizable metal powder selected from the group consisting of iron powder and aluminum powder, the particle size of said abrasive material predominantly containing quartz being larger than that of said oxidizable metal powder.
• thermochemical refractory body cutting and scarfing adjuvant powder mixture containing between 10 and 80 percent by weight sand material having particle sizes Substantially distributed between about 30 and 100 mesh, and the remainder at least one oxidizable metal powder selected from the group consistin of iron powder and aluminum powder having particle sizes distributed over the range from 30 mesh to finer than 325 mesh.
• thermochemically removing material from a refractory body wherein a stream of oxidizing gas and adjuvant powdered material are concurrently directed against a heated zone of such body
• improvement which comprises contributing abrasive action to said metal removal by employing as said adjuvant powdered material a mixture containing between 10 percent by weight and percent material predominantly containing quartz and having particle sizes substantially distributed between about 30 mesh and mesh and the remainder at least one oxidizable metal powder selected from the group consisting of iron powder and aluminum powder.
• thermochemically removing material from a refractory body wherein a stream of oxidizing gas and adjuvant powdered material are concurrently directed against a heated zone of such body
• said adjuvant powdered material a mixture containing between 10 percent and 80 percent by weight abrasive material predominantly containing quartz and the remainder at least one elemental oxidizable metallic powder selected from the group consisting of iron powder and aluminum powder, the particle sizes of said quartz-containing constituent being substantially distributed between about 30 mesh and 100 mesh, the particle size of said quartz-containing material being larger than that of said oxidizable metal powder.
• thermochemical removal of material from a refractory body which comprises directing against said body at least one preheating flame envelope to heat a portion of said body, directing at least one stream of material-removing oxidizing gas against the heated portion of said body, and concurrently directing at least one stream of adjuvant powdered material against said heated portion of said body, said adjuvant powdered material containing a mixture of between 10 percent and 80 percent by weight sand having particle sizes substantially distributed between about 30 mesh and 100 mesh and the emainder at least one oxidizable metal powder selected from the group consisting of iron powder and aluminum powder having particle sizes distributed over the range from 30 mesh to finer than 325 mesh.
• thermochemical removal of material from a refractory body which comprises directing against said body at least one preheating flame envelope to heat a portion of said body, directing at least one stream of material-removing oxidizing gas against the heated portion of said body, and concurrently directing at least one stream of adjuvant powdered material against said heated portion of said body, said adjuvant powdered material containing a mixture of between 10 percent and 80 percent by weight material predominantly oontaining quartz and the remainder at least one oxidizable metal powder selected from the group consisting of iron powder and aluminum powder, the particle size of said quartzcontaining material being larger than that of said metallic powder and substantially distributed between about 30 mesh and 100 mesh.
• thermochemical refractory body gas borne cutting and scarfing adjuvant powder mixture containing between and 80 percent by weight material predominantly containing quartz and the remainder at least one oxidizable metal selected from the group consisting of iron powder and aluminum powder, said predominantly quartz-containing material having particle sizes larger than those of said metal and substantially distributed between about 30 and 60 mesh.
• a bonded flowable thermochemical refractory body gas borne cutting and scarfing adjuvant powder mixture containing a small quantity of a bonding agent and between 10 and 80 percent by weight material predominantly containing quartz and the remainder at least one oxidizable metal selected from the group consisting of 7 iron powder and aluminum powder, said predominantly quartz-containing material having particle sizes larger than those of said metal and substantially distributed between about 30 and 100 mesh.
• thermochemicallyremoving material from a refractory body wherein a stream of oxidizing gas and adjuvant powdered material are concurrently directed against a heated zone of such body
• improvement which comprises contributing abrasive action to said material removal by employing as said adjuvant powdered material a mixture containing between 10 percent and 80 percent by weight material predominantly containing quartz and having particle sizes substantially distributed between about 30 mesh and 100 mesh and the remainder at least oneoxidizable metal powder selected from the group consisting of iron powder and aluminum powder, the particle size of said material predominantly containing quartz being larger than that of said oxidizable metal powder.
• thermochemically removing material from a refractory body wherein a stream of oxidizing gas and adjuvant powdered material are concurrently directed against a heated zone of such body
• said improvement which comprises contributing abrasive action to said material removal by employing as said adjuvant powdered material a mixture containing between 10 percent and 80 percent by weight material predominantly containing quartz and the remainder at least one oxidizable metal powder selected from the group consisting of iron powder and aluminum powder, the particle size of said material predominantly containing quartz being larger than that of said oxidizable metal powder and substantially distributed between about 30 mesh and 100 mesh.
• thermochemical and abrading removal of material from a refractory body which comprises directing against said body at least one preheating flame envelope to heat a portion of said body, directing at least one stream of material-removing oxidizing gas against the heated portion of said body, and concurrently directing at least one stream of adjuvant and abrasive powdered material against said heated portion of said body, said adjuvant and abrasive powdered material containing a mixture of between 10 percent and percent by weight material containing predominantly quartz and having particle sizes substantially distributed between about 30 mesh and mesh, and the remainder at least one oxidizable metal powder selected from the group consisting of iron powder and aluminum powder.
• thermochemical and abrading removal of material from a refractory body which comprises directing against said body at least one preheating flame envelope to heat a portion of said body, directing at least one stream of material-removing oxidizing gas against the heated portion of said body, and concurrently directing at least one stream of adjuvant and abrasive powdered material against said heated portion of said body, said adjuvant and abrasive powdered material containing a mixture of between 10 percent and 80 percent by Weight material containing predominantly quartz and having particle sizes substantially distributed between about 30 mesh and 100 mesh, and the remainder at least one oxidizable metal powder selected from the group consisting of iron powder and aluminum powder.
• thermochemical and abrading removal of material from a refractory body which comprises directing against said body at least one preheating flame envelope to heat a portion of said body, directing at least one stream of material-removing oxidizing gas against the heated portion of said body, and concurrently directing at least one stream of adjuvant and abrasive powdered material against said heated portion of said body, said adjuvant and abrasive powdered material containing a bonded mixture of between 10 percent and 80 percent by weight material containing predominantly quartz and having particle sizes substantially distributed between about 30 mesh and 100 mesh, and the remainder at least one oxidizable metal powder selected from the group consisting of iron powder and aluminum powder.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Compositions Of Oxide Ceramics (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=24326805

Family Applications (1)

Country Status (2)

Cited By (5)

Citations (4)

• 1956
  • 1956-05-01 US US581847A patent/US2855337A/en not_active Expired - Lifetime
• 1957
  • 1957-04-30 FI FI0736/57A patent/FI40134B/fi active

Patent Citations (4)

Also Published As

Similar Documents