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
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
  • B23K35/38—Selection of media, e.g. special atmospheres for surrounding the working area
  • B23K35/383—Selection of media, e.g. special atmospheres for surrounding the working area mainly containing noble gases or nitrogen
• • 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
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
  • B23K35/224—Anti-weld compositions; Braze stop-off compositions
• • 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
  • B23K9/00—Arc welding or cutting
  • B23K9/16—Arc welding or cutting making use of shielding gas
  • B23K9/173—Arc welding or cutting making use of shielding gas and of a consumable electrode

Definitions

• the invention relates to the metal-inert gas (MIG) arc welding process in which an inert gas is directed around an electrode while effecting arc welding
• the problem to which this invention is directed relates to build up of spatter during the welding process.
• spatter will collect and adhere on all of parts adjacent a welding arc apparatus including a gas cowl and the nozzle through which the continuously feeding metal rod is being directed. Such spatter will build up to interfere with both the welding process and the free exiting of either the consumable metal rod or the free flow of the inert gas.
• this invention can be said to reside in the method of injecting into an inert gas as it is being supplied to the welding head during the welding process, a liquid selected so that when this substance reaches the weld site it will have the capability to reduce the capacity for any spatter being formed to adhere to adjacent materials.
• spatter retardant liquid material is injected so that it is substantially dispersed within the inert gas such that it will exit with the inert gas during the welding process.
• inert gas is introduced into a reservoir of the spatter retardant liquid and bubbled through the liquid thereby forming a dispersion or fine mist of the spatter retardant liquid in the inert gas.
• This method of injecting the spatter retardant liquid into the inert gas is particularly preferred because it appears that only a sufficient quantity of spatter retardant liquid is introduced into the inert gas, thereby avoiding any problems which can occur when an excessive quantity of the liquid is introduced into the inert gas.
• the spatter retardant liquid that has been found to be particularly advantageous in this application comprises a mixture of one or more hydrocarbon liquids, preferably a petroleum distillate.
• hydrocarbon liquids preferably a petroleum distillate.
• material produced by distillation within the range of 250°C to 400°C has been found to be suitable.
• the material commonly available under the name "diesel fuel” is an example of a material suitable for use in the spatter reduction technique of the present invention.
• the injection of the spatter retardant liquid into the gas can be achieved by other means, for example, in several trials, I injected a very small quantity of diesel fuel in distributed manner into the gas supply of a MIG welder using a conventionally available device known as a lubricator.
• a lubricator This was a prep-air airline lubricator of a type that is conventionally available in engineering and which allows a diesel fuel drip to be injected into the gas line at a rate proportional to the volume of inert gas passing through it, giving a smooth flow of diesel via a combination ball check and metering of valve which automatically adjusts diesel feed according to gas demands from downstream.
• a supply of diesel fuel can be kept in a filled bowl with an adjustment allowing for change of the feed rate which is adjusted for each application but once set is constant through the period of an application.
• the gas that I have used this with in the example is argon.
• the invention can also reside in the method of welding which comprises the steps of introducing the spatter retardant liquid into the inert gas line during the welding process.
• the invention can reside in a welding apparatus comprising an inert gas welding system including an inert gas supply, and means in-line to introduce a selected spatter retardant liquid during the welding process.
• the source of the spatter retardant liquid is a sealed container disposed between the inert gas supply means and the welding hand piece, and in which the inert gas passes, through an inlet into the container and through the spatter retardant liquid in bubble form, the inert gas collecting in a space above the surface of the liquid, a portion of the spatter retardant liquid being entrained in the inert gas as a dispersion or a fine mist, the inert gas and entrained gas being subsequently delivered to a weld site through the welding hand piece.
• One of the advantages of the arrangement described is that it can be provided on an ongoing continuous basis so that down time from spatter build-up can be significantly reduced.
• FIG. 1 shows in schematic outline the apparatus according a first embodiment of the present invention
• FIG 2 illustrates an apparatus in accordance with a second aspect of the present invention.
• FIG 1 there is a work piece 1 on which a weld 2 is being formed.
• a MIG handpiece includes a cowl 3 for directing gas around the nozzle 4 and the metal welding rod 5.
• the metal rod 5 is fed through the nozzle 4 by drive means (not shown) and is consumed during the welding process.
• An inert gas supply is provided through conduit 6 from a sealed container 7 in which there is a reservoir of the spatter retardant liquid used for the method.
• the liquid is chosen for its effectiveness so that it will be capable of forming a mist and therefore be able to be transferred in a stable form to an outlet of the handpiece.
• the material used in this instance is a liquid containing petroleum distillate, mineral oil and corrosion inhibitors.
• a material is available from CRC Chemicals Australia Ply Ltd, its characteristics being those set out hereunder, namely;-
• inlet tube 9 With spatter retardant liquid in the chamber, there is a gas inlet directed through inlet tube 9 such that the gas will issue in bubble form and therefore cause some splashing and vapourisation so that this is collected in space 10 above the level of the liquid 8.
• An external level indicator 11 is supplied through control valve 12 and this in turn is supplied from a gas regulator connected to a gas supply bottle at 13.
• spatter retardant liquid coats the adjacent surfaces such as the nozzle 4 and the cowl 3, which coating, in the vicinity of an oxygen excluding gas, will not readily burn and therefore will act to effect an interface surface which will be only slowly vapourised in the vicinity of the general heat of the world but will be rapidly vapourised when hit by spatter.
• the rate of providing of the liquid would in this case be sufficient to replace the coating as it is vapourised with the slower radiant heat from the arc.
• FIG 2 illustrates a second embodiment of the present invention.
• the arrangement depicted in FIG 2 shares many common features with the embodiment of FIG 1 and like parts have been given like numerals.
• Shown in the drawing is a workpiece 1 in which a weld is being formed.
• An MIG hand piece includes a cowl 3 for directing gas around a nozzle 4 and a metal welding rod 5.
• the welding rod 5 is fed through the nozzle 4 by drive means (not shown) and is consumed during the welding process.
• An inert gas supply is provided through conduit 6 from an in-line liquid distributor 14.
• the liquid distributor 14 receives an on demand supply of gas through conduit 15.
• the spatter retardant liquid 16 comprises diesel fuel and is held in a bowl in the distributor 14. Through an adjustable setting of the head 17 controls the distribution of the liquid in a dispersed manner into the gas.
• the material can be introduced and be maintained within the gas line and not acceptably interact with the inert gas to the detriment of the arc process.
• Materials other than diesel fuel therefore can be selected having these characteristics and other oil or petroleum distillates may be suitable.
• Selected hydrocarbon materials can provide when introduced in the vicinity of the weld a reduction of the ability of spatter to stick and to the extent that there are other compounds and materials which provide this purpose, the invention is directed to introducing these in liquid form into the gas.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Arc Welding In General (AREA)

Applications Claiming Priority (5)

Publications (2)

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Family Applications (1)

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Citations (3)

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• 1993
  • 1993-11-24 CA CA 2150001 patent/CA2150001A1/en not_active Abandoned
  • 1993-11-24 WO PCT/AU1993/000596 patent/WO1994012312A1/en not_active Ceased
  • 1993-11-24 EP EP94900631A patent/EP0670761A4/de not_active Withdrawn

Patent Citations (3)

Non-Patent Citations (1)

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