Showing papers on "Submerged 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.

Automatic pipe welding apparatus and method

Abstract: A TIG pipe welding method which employs two sets of machine guide surfaces on the pipe ends. First radially inner guide surfaces cooperate with a sensor coupled to the welding torch to continuously monitor the arc gap between the welding electrode and the weld puddle as the welding electrode moves around the circumference of the pipe. The second set of radially outer surfaces cooperate with a welding carriage to guide the carriage and welding modules around the pipe joint. The carriage is constructed to provide a sealed welding chamber surrounding the electrode. An additional flow of shielding gas is provided around the torch electrode of a TIG or hot wire TIG welding module to augment the normal gas shield. The augmented shield provides a gas flow in opposition to pressurized air flowing through the welding chamber to prevent exposure of the weld nugget to the pressurized air flow being maintained in the welding chamber while permitting the pressure forces to be transmitted through this shield to the weld nugget, creating a "puddle pushing" effect. The transfer of forces through the gas shield, while preventing contaminating air from entering the weld zone itself, provides a positive force for pushing the molten weld puddle through the joint to the interior surfaces of the joined pipe ends. The pressurized air further flows outwardly between the seals of the welding carriage and the pipe surfaces to create an air cushion between the pipes and the carriage. An internal weld backup and pipe alignment ring is also provided.

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.

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 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.

Computerized process and apparatus for use with a submerged arc electric furnace to produce metallurgical products

Abstract: The invention relates to a computerized process and apparatus for automatically regulating the power, feed rate and electrode position of hollow or solid electrodes in submerged arc electric furnaces used for the production of quality-controlled metallurgical products such as calcium carbide.

Xenon arc discharge lamp having a particular electrode composition and wherein the arc discharge is obtained without heating the electrode

Abstract: An electrode for an arc discharge lamp includes a porous sintered body of tungsten impregnated with a mixture of alkaline earth oxides and a metal oxide. The alkaline earth materials may be oxides of barium and calcium, and the metal oxide may be aluminum oxide. The body is brazed or welded to the end of a high melting point refractory metal support of tungsten or molybdenum. Two identical electrodes are used as the cathodes of a long arc alternating current type xenon lamp and one such electrode provides the cathode of a short arc direct current xenon lamp. The structure and materials provide greater efficiency and extended life under continuous operating conditions.

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

Method for longitudinally seam-welding pipe-blank for welded steel pipe from the inside along a groove

Abstract: In longitudinally seam-welding a pipe-blank for welded steel pipe from the inside along a groove by the reverse-polarity GMA welding process comprising using direct electric current supplied to a consumable electrode through a cable as the welding current with said consumable electrode as the anode, the direction of said direct electric current for welding flowing through said cable introduced into said pipe-blank is set in the same direction as that of welding, thereby preventing occurrence of a magnetic arc blow of the welding arc from said consumable electrode toward the upstream side of the welding direction, ie, in the opposite direction to that of welding

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

Solidification cracking of ferritic steels during submerged-arc welding

Abstract: This report is concerned with a programme sponsored in 1971 by 15 companies together with Det norske Veritas and ESAB to investigate solidification cracking during submerged-arc welding which, at that time, showed signs of becoming an increasingly severe problem. Although weld solidification cracking (hot cracking) is not a new problem, it was not encountered to any serious extent in welding structural and pressure-vessel steels until the advent of submerged-arc welding. This process, with its characteristically large weld pools and capacity for high energy inputs, is particularly prone to solidification cracking, which may vary in intensity from isolated small defects to the cracking of entire weld seams. The results of the investigation are summarised together with other knowledge in this field, in such a way as to be of help to fabricators and others who may be concerned with welding C-Mn steel and, in a more general way, low-alloy steels. The subject is covered under the following headings: Description of solidification cracking. Detection, significance, and identification. Avoidance of solidificaton cracking. Remedial measures when cracking is encountered during fabrication. Order from: BSRA as No. 47,325.

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.

Bonded flux for three o*clock submerged arc welding

Abstract: PURPOSE:To obtain a clean weld metal having no internal defect such as slag inclusion, blowholes, etc. by incorporating a prescribed ratio of CaF2, BaF2, NaF, AlF3, MgF2, CaCO3, MgCO3, etc. in a flux. CONSTITUTION:A titled flux consists of 20-80%, >=1 kind among CaF2, BaF2, NaF, AlF3 and MgF2, 1-7% (in terms of CO2) metallic carbonate such as CaCO3, MgCO3 or the like, 0.5-5% Al<=1.5% K2O and a binder, etc. A clean weld metal having no internal defects such as slag inclusion and blow holes, etc. is obtd. by such flux.

Submerged arc welding method for steel plate

Abstract: PURPOSE: To efficiently form the weld zone with well-balanced deep penetration, when butt-welding the steel plate, by rotating the tip of the welding core wire so as to picture the specified locus, and besides, by impressing the suitable welding-currentdensity on the core wire. 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

Arc chute having plates coated with weld deterent material

Abstract: An arc chute for assisting in the extinction of an arc drawn between circuit interrupting contacts opening in air includes a stack of closely spaced metallic plates coated with a weld deterent material, such as silicone varnish. By virtue of this coating, the propensity of metal particles condensed from the metal vapor generated by the arc to weld to the arc plate surfaces is reduced. Consequently, material degradation of the arc chute dielectric strength is avoided, and arc reignition is discouraged.