Showing papers on "Gas metal arc welding published in 1977"

Method of and device for plasma MIG welding

Abstract: Plasma-MIG welding involving the use of two parallel consumable electrodes axially introduced into a plasma arc initiated by a non-consumable electrode and out through a nozzle. All three electrodes are maintained at a positive polarity whereby a substantial increase of the deposition rate is achieved, without rotation of the MIG-arcs and without exceeding the critical current intensity.

Flux cored wire for welding Ni-Cr-Fe alloys

Abstract: A self-shielding, flux cored arc welding electrode for joining Ni-Cr-Fe alloys and overlaying dissimilar metals. The wire has a nickel-chromium containing alloy sheath and a flux core containing special proportions of carbonates, fluorides, metal oxides, and powdered metals. Sound welds can be prepared without the use of a supplemental inert shielding gas. Welded joints provide essentially the same properties as those of the Ni-Cr-Fe base alloy.

Arc furnace for reducing metal oxides and method for operating such a furnace

Abstract: An arc furnace has an arcing electrode through which a feeding passage is formed for feeding metal oxide particles through an arc and to a melt in the furnace. The arc is powered by DC power with the electrode cathodic and the melt anodic. Carbon is fed as required to reduce the oxides. Electric currents passing through the melt and the arc to the electrode are capable of causing magnetic forces forcing the arc to acquire an angular deflection in a downward direction away from alignment with the electrode's outer periphery and towards the side wall of the furnace in one direction subst antially continuously, during continuous operation of the furnace. Means are provided for electromagnetically causing the arc to continuously rotate, with its deflection, around the electrode. BACKGROUND OF THE INVENTION

Method and apparatus for tig welding

Abstract: A method for TIG welding by using a plurality of nonconsumable electrodes extending frm the tip of a TIG welding torch and one filler wire fed through a space between the electrodes, each electrode being independently supplied with power. A molten pool is formed by melting both the base metal to be welded and the filler wire by means of arcs generated between respective electrodes and the base metal. Melting of the base metal is mainly controlled by the arc produced by one of the plurality of electrodes while melting of the filler wire is mainly controlled by the arc generated by the other electrode.

Welding apparatus with shifting magnetic field

Abstract: The present invention relates to a welding process and apparatus. More particularly, the invention relates to a welding process and apparatus for performing welding in various positions characterized in that a shifting magnetic field is generated in the vicinity of a molten metal pool to induce an eddy current in the molten metal pool, whereby an electromagnetic driving force is caused to act on the molten metal pool to control the shape of the molten metal pool, and welding is carried out while controlling the shape of the molten metal pool in this manner. According to the welding process and apparatus of the present invention, the welding efficiency can be enhanced irrespective of any welding positions.

Method of and device for arc welding

Abstract: A method of plasma MIG welding in which an arc is maintained between a workpiece and a welding wire in a thermally ionized gas (auxiliary plasma) which is generated by an electric gas-discharge between two non-consumable electrodes; neither the welding wire nor the workpiece acts as a single electrode for generating the thermally ionized gas.

Method of arc welding under water

Abstract: In a method of arc welding under water or at superatmospheric pressure (or both) the weld is made in a chamber containing a gaseous atmosphere. The weld metal is deposited from flux-cored welding wire whose core contains strong deoxidant(s) such as aluminium, magnesium, titanium, zirconium, lithium and calcium. A shielding gas containing a selected proportion of oxygen or oxygen-containing gas but consisting mainly of an inert gas such as argon or helium is employed to surround the arc. The shielding gas is constituted by the atmosphere in the chamber.

Combination welding torch for shielded inert gas or electric arc welding

Abstract: Welding torch comprises a combination collet body which functions interchangeably for electric arc welding, of the open arc type using a consumable electrode, or for inert gas shielded welding using a non-consumable electrode The collet body has a screw-threaded collar at one end which is screwed into the welding head At the other end, it has a slitted or splined chuck The slightly enlarged central body portion between the collar and the chuck includes a plurality of gas vents For open arc welding, a consumable electrode, interposed into the chuck, is secured in place by a constricting metal adapter sleeve which also serves to close the gas vents For inert gas shielded welding, the consumable electrode and the metal adapter are replaced by a nonconsumable electrode and a ceramic shield open at one end The open vents permit inert gas to escape under the ceramic shield and surround the nonconsumable electrode during the welding process

Method of connecting metallic parts by means of arc fusion welding

Abstract: A method of connecting metallic parts, and metallic parts so produced, by means of arc fusion welding by producing a low volume welding seam (narrow gap welding), wherein the workpiece parts to be jointed and forming a narrow gap are initially welded at their butt joint by means of, for instance, electron-beam welding, plasma-arc welding, laser-beam welding or argon arc-welding to produce a base seam with or without filler material, and thereafter the workpiece flanks forming the narrow gap are united by alternately depositing weld beads at first one and the other workpiece flank by submerged-arc welding.

A review of minor element effects on the welding arc and weld penetration

Abstract: A critical review of all the available literature pertaining to welding arc and weld penetration has been undertaken The review revealed several studies which indicate that the intentional or unintentional addition of small amounts of halides to the base material significantly improves weld penetration The presence of oxygen in the weld materials has been reported to have both positive and negative effects on the depth and shape of the weld Various other elements present in the base material have been alluded to as a means of changing the penetration characteristics of the GTAW process In particular, aluminum addition to the arc or excessive aluminum in the base material has been observed to produce a flared arc at the anode surface In many cases these changes are accompanied by variations in the arc voltage which, if properly interpreted can act as a warning signal for potential problems The general conclusion of all the published reports stress the need for additional systematic study and further research into this problem area in order to understand the causes and effects that have been noted experimentally An attempt has therefore been made to provide some beginning and rationale for understanding how the properties of minor elements can affect the factors which influence weld penetration In particular, the factors discussed relate to changes in the work function of both the anode and cathode surfaces, the arc voltage and arc configuration, in addition to surface tension effects of the weld puddle and arc stability In order to provide much-needed additional experimental data to this problem area, a spectroscopic analysis of a typical GTAW arc was undertaken and a simple test initiated to determine the "penetration" qualities of various heats of EN 82 filler material The results and conclusions of these studies are reviewed

Method of multi-pass narrow groove arc welding

Abstract: A method of multi-pass arc welding with a consumable electrode in a protective atmosphere for welding heavy-gauge metal with narrow grooving, wherein, according to the invention the initial electrode extension is adjusted to be greater than the depth of grooving of welded joint, a current supply conductor which supports the consumable electrode passing therethrough is placed in a permanent position above the welded joint, and the welding is conducted with the length of extension of consumable electrode decreasing upon each pass, the voltage applied to the current supply conductor, rate of feed of the consumable electrode and welding speed being reduced with the decrease in the length of extension of the consumable electrode.

Welding, a steel suitable for use therein

Abstract: A steel which contains up to 0.15% carbon, 0.5 to 1.5% manganese, 0.03 to 0.10% silicon, less than 0.2% molybdenum, up to 0.05 aluminum, 0.03 to 0.05% titanium and 0.002 to 0.008% boron is particularly suitable as a welding consumable, for example as an electrode for the submerged arc welding of high strength micro-alloyed structural steels. Especially when used with a basic flux, welds can be produced showing excellent notch toughness characteristics.

Narrow weld-groove welding process

Abstract: A narrow weld-groove welding process, in which a bare welding wire is fed into a weld groove defined between the opposed surfaces of two pieces of metals for producing a metal arc therein for welding. In this process, a welding wire is subjected to a plastic deformation of a wave form, before being fed into a nozzle hole provided in a contact tip, and then the wire is fed into a nozzle hole, while maintaining elasticity tending to cause waving, whereby the tip of a welding wire being fed through a nozzle exit is automatically weaved between the opposed surfaces of metals to be joined, with the tip of wire being alternately faced in the opposite directions, in response to the weaving motion thereof, with the feeding of the welding wire and progress of welding. In addition, the apparatus for use in a narrow weld-groove welding process is also disclosed.

Method of and device for plasma-MIG welding

Abstract: Plasma-MIG welding in which a thermally ionizable inert gas stream is flowed through a nozzle non-consumable electrode having a central aperture and a surrounding annular aperture toward a workpiece and is thereby split into a central gas column enveloped by an annular gas shield. A consumable electrode is fed through the central gas column toward the workpiece, with the establishment of a MIG-arc therebetween. A plasma arc is spontaneously established by means of the MIG-arc between the nozzle non-consumable electrode and the workpiece.

Preliminarily treating method for diffusion welding of stainless steel, aluminum or aluminum alloy

Abstract: PURPOSE: To enable the effective diffusion welding, by electrolyzing in the electrolytic solution using the welding material consisting of stainless steel or Al(alloy) as the anode, removing the oxide and nitride coating on the surface and then immediately plating a specified metal respectively using the welding material as the cathode. COPYRIGHT: (C)1978,JPO&Japio

Automatic arc welding method for high efficiency multielectrodes of low temperature high toughness steel

Abstract: PURPOSE: To weld the thick steel plate, having a superior low temperature toughness, with a high efficiency, by forming the root pass bead with HIG welding using the wire, restricted C, P, S by multielectrodes automatic welding and carrying out submerged arc welding by heat input quantity of the wire, having a specific composition. COPYRIGHT: (C)1978,JPO&Japio

Apparatus and method for inert gas arc welding

Abstract: An arc welding torch terminates in a gas cup open at one end through which an electrode projects. Inert gas is introduced under pressure at the other end of the gas cup and flows past and through a gas diffuser disposed in said gas cup. The diffuser is spaced from the inner wall of the gas cup, and a portion of the gas flows axially parallel to the central axis of the gas cup. The diffuser has a set of passageways to form and direct columns of gas in an outward direction, and another set of passageways to form and direct columns of gas in an inward direction. The diffuser is axially and angularly adjustable to vary the pattern of gas discharge with relation to the arc and to control the contour of the weld bead. BACKGROUND OF THE INVENTION The present invention relates to inert-gas arc welding, and more particularly, to a method and apparatus for applying a shielding gas in the welding operation. In the conventional arc welding processes, such as either the TIG (tungsten inert-gas type) or the MIG (consumable inert gas type), the heat generated by the electrical arc is utilized to reduce the metal material to be joined to a molten state to effect fusion between the parts to be joined. Most metals in a molten state will react with atmospheric gases, usually resulting in an unstable arc and a poor weld. In one known process for stabilizing the arc, when welding aluminum plate or the like, a shielding gas, which is normally argon or helium, is utilized to surround the arc and exclude atmospheric gases from the weld area and prevent oxidation of the molten metal which will ultimately form the weld. In addition, the gas provides a low resistance path for the arc and the gas ions provide a cleaning action by bombardment of the metal surfaces to be welded. Various problems have existed in the application and utilization of the shielding gas. For example, optimum cleaning action was not achieved. Weld bead contours were not as controllable as desired. A very close torch cup to work distance had to be maintained to prevent disruption of the gas pattern by external forces. Moreover, the efficiency of the gas consumption was less than desired. In addition, when welding in vertical position, the weld metal flow and solidification patterns were less than optimum. An example of a plasma generating torch is shown in U.S. Pat. No. 3,604,889 but in such patent the gas, instead of being directed in columns, is cone-shaped and is concentrated into a stream which penetrates the arc externally of the torch. Moreover, there is not axial or angular adjustment of the stream. SUMMARY OF THE INVENTION A gas cup substantially closed at one end and open at the other has an electrode disposed therein. An inert gas entrance means is disposed remote from the open end. A diffuser in accordance with the present invention is mounted to direct the gas in a predetermined manner relative to the arc and the pieces to be welded, in accordance with the present invention. The diffuser is adapted to form and direct columns of the inert gas in an outwardly flaring direction from the central axis of the electrode and to form and direct other columns of the inert gas towards the longitudinal central axis of the electrode. The diffuser also coacts with the body of the torch to form a cylindrical column of gas which surrounds the directed columns of gas to provide a protective shield for the directed columns. The diffuser is adjustable axially and/or angularly with reference to the electrode, whereby the gas columns may be varied for the most efficient operation. By the foregoing arrangement, improved cleaning patterns provided by the cleaning action of gas ions bombarding the metal surface has been achieved, and improved weld bead contours have been obtained. The torch cup to work distance is not as critical, and the disruption of the gas pattern by external forces is reduced. The gas consumption for a given torch nozzle size and set of welding parameters has also been reduced by the improved utilization of the gas to provide optimum effect. Moreover, improved weld metal flow and solidification patterns have been obtained when welding in the vertical position.

Welding method for manufacture of thick walled steel pipe

Abstract: PURPOSE: To improve the low-temperature toughness of the weld zone in the thick walled steel pipe, by finishing the surface layer of the weld zone according to the submerged arc welding, after carrying out the MIG welding on the groove face, prepared into a specified shape, by supplying a large welding current to the thin wire and by giving a vibration to this thin wire. COPYRIGHT: (C)1978,JPO&Japio

Welding method by direct current gas shielded arc

Abstract: PURPOSE: To form the weld zone having a superior mechanical property with a high welding efficiency without producing a bad bead by deoxidation product, by carrying out direct current gas shielded arc welding with shielding gas, core wire and more than two electrodes applied different welding current. CONSTITUTION: On occasion of using two electrodes, the distance between the preceding electrode 1 and the succeeding electrode 2 is kept apart more than 100mm. Shielding gas mixed more than 30% of CO 2 gas or less than 5% of O 2 gas with inactive gas, such pure Ar gas or He gas etc., is used in the ratio of 15W100l/ min. at the electrode 1 and 0.6W1.6mmϕ of the core wire 12 and 100W500A of welding current, are used. Shilelding gas mixed 7.5W50% of CO 2 or 1W10% of O 2 gas with pure Ar gas or He gas, is used in the ratio more than 50kg/min. at the electrode 2. 3W6.4mmϕ of large core wire is used for the core wire 22 and 600W1500A of welding current is used. The deoxidation product 8 is not moved in fron of arc and the weld zne 7 havig a superior impact value, is able to obtain. COPYRIGHT: (C)1979,JPO&Japio

Welding method for ferritic stainless steel

Abstract: PURPOSE: To weld ferritic stainless steel efficiently to produce weld joint of excellent mechanical property by utilization of metallurgical reaction of CO 2 and molten metal through mixing CO 2 of specific quantity with inactive shield gas for nonconsumable electrode type arc welding machine. COPYRIGHT: (C)1978,JPO&Japio

Method of and apparatus for welding sheet steel panels

Abstract: A method of and apparatus for welding sheet steel panels by submerged arc welding is described. By providing one or, depending on the thickness of the sheet steel panels, more than one pair of closely spaced wire electrodes in the weld gap with the simultaneous introduction of additional filler metal carrying no current, preferably in the form of a metal powder, disadvantages associated with known methods may be avoided.

Inductive preheating of wire or strip welding electrodes - before immersion in melting bath or before arc ignition

Abstract: Wire- or strip electrodes are inductively heated before immersion in melting bath or before ignition of arc. After passing through weld current contact, the electrodes are passed through an induction circuit. Preheating achieved can be varied and can be brought to 1000 degrees C, according to welding process and alloy compsn. Inductive preheating of currentless wire- or strip electrodes takes place directly (30-50 mm) before immersion in melting bath. Heating method can be applied to electrodes of all profiles and dia., for welding processes including metal active-, MIG, TIG, submerged arc-, electroslag and filler wire welding, opt. under a protective gas. Inductive preheating of filler wire electrodes helps to achieve an additional drying of the often hygroscopic flux fillings. Fusing efficiency is not reduced. Burning down of alloying elements is reduced, and degradation of alloying elements, by dilution with substrate material is prevented.

Device and welding torch for plasma-mig-welding

Abstract: A compact plasma-MIG welding torch in which the contact tube and the nozzle are directly connected together electrically, thereby enabling welding with a very short extension of the welding wire

One-side arc welding method for 9% ni steel

Abstract: PURPOSE: To obtain sufficient welded joint strength as well as uniform Uranami in one-side arc welding of thin 9% Ni steel by specifying the shape of bevel, the compsn. of a weld material and that of a secondary filler metal so as to reduce dilution of a weld metal with the base material. COPYRIGHT: (C)1978,JPO&Japio

Method and apparatus for energy beam welding with filling material

Abstract: A deep penetration weld join is produced in an energy beam welding method where the energy beam, as for example, an electron beam, is directed into the join to produce a welding zone containing molten material, and moved along the join relative to the parts of the work. Additional material is introduced into the welding zone to fill a gap and/or to influence the metallurgical composition of the weld zone. By introducing the material into the melt at an acute angle to the beam axis and at a point spaced alongside the beam axis, the additive material penetrates deeply into the molten material. The additive material may be preheated prior to its introduction to the welding zone.

Welding method for electron beam of high carbon steel material

Abstract: PURPOSE: To prevent the occurrence of crack at welding part, by carrying out electron beam welding, butting overlay welding part, after carrying out overlay welding of steel, being carbon content less than 0.20%, on welding surface, at the time of welding high carbon steel, containing carbon more than 3.30%. COPYRIGHT: (C)1978,JPO&Japio

Multiple-electrode welding for line pipe

Abstract: PURPOSE: To carry out the defectless welding with good bead appearance with low heat input under a condition of wide range, by applying the MIG welding method to the first electrode, the submerged arc welding method to the second electrode, etc. COPYRIGHT: (C)1979,JPO&Japio