Showing papers on "Gas metal arc welding published in 1978"

Mutagenicity of fume particles from metal arc welding on stainless steel in the Salmonella/microsome test

Abstract: Mutagenic activity of fume particles produced by metal arc welding on stainless steel (ss) is demonstrated by using the Salmonella/microsome mutagenicity test described by Ames et al., with strain TA100 (base-pair substitution) and TA98 (frame-shift reversion). Results of a representative but limited selection of processes and materials show that mutagenic activity is a function of process and process parameters. Welding on stainless steel produces particles that are mutagenic, whereas welding on mild steel (ms) produces particles that are not. Manual metal arc (MMA) welding on stainless steel produces particles of higher mutagenic activity than does metal inert gas (MIG) welding, and fume particles produced by MIG welding under short-arc transfer conditions are more mutagenic than those produced by spray-arc transfer. Further studies of welding fumes (both particles and gases) must be performed to determine process parameters of significance for the mutagenic activity.

Apparatus for connecting metallic parts by means of arc fusion welding

Abstract: An apparatus for 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 joined 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

Multiple electrode submerged arc welding method

Abstract: A submerged arc welding method and more specifically, a multiple electrode welding method is disclosed wherein welding is performed by arranging electrodes in such a manner that the distance becomes at least 300 mm between a first molten pool formed by multilayer welding or by a single or plural electrodes preceding along the weld line and a subsequent molten pool formed by a single subsequent electrode or plural subsequent electrodes, as well as a submerged arc welding method which is characterized in that there is formed a slag having the components listed below on the weld metal formed by an electrode or a preceding electrode forming a preceding layer, and welding is carried out as such, without removing the slag, using an electrode or a subsequent electrode forming a subsequent layer; TiO 2 : 20-65% by weight (up to 60% by weight, based on the total TiO 2 amount, of which may be substituted by ZrO 2 ); CaF 2 : 9.6-40% by weight, and Al 2 O 3 : 10-56% by weight.

A process for the diffusion welding of copper and stainless steel

Abstract: A process for the diffusion welding of copper and stainless steel, which comprises sandwiching a thin layer of at least one metal selected from the group consisting of Ni, Ni-base alloys, Cr, Ni-Cr, and Cr-Ni with little gas contents, as an insert metal, between the surfaces of copper and stainless steel to be bonded, and then diffusion welding the sandwich.

Method of cold welding using ion beam technology

Abstract: A method for cold welding metal joints. In order to remove the contamination layer on the surface of the metal, an ion beam generator is used in a vacuum environment. A gas, such as xenon or argon, is ionized and accelerated toward the metal surface. The beam of gas effectively sputters away the surface oxides and contamination layer so that clean underlying metal is exposed in the area to be welded. The use of this method allows cold welding with minimal deformation. Both similar and dissimilar metals can be cold welded with this method.

Welding process for production of a steel pipe

Abstract: Disclosed herein is an improvement of a welding process for welding a steel pipe, wherein a gas metal arc welding is performed to form the first welding layer and a submerged arc welding is performed to form the last welding layer. According to the conventional gas metal arc welding process, i.e. the MIG or CO2 welding processes, the combined use of a high welding current and a welding wire having a small diameter is known to bring about the rotation of the welding arc and the formation of an undercut along the toe of the weld metal. The purpose of the present invention is to weld a steel pipe having either a large thickness or an excellent ductility at a temperature of less than -40° C., or both. According to the present invention, the combined use of a high welding current and a wire having a small diameter is possible, by employing a gas mixture containing an inert gas as a major part thereof and CO2 as an additional part thereof as a shielding gas. In addition, by adequately selecting the wire extension, the gas metal arc welding is improved to provide the features of: deep and round penetration; stable arc formation with stiffness of the arc, and; high metal deposition rate.

Method of arc welding with reverse side cooling for obtaining highly tough large-diameter welded steel pipes

Abstract: An arc welding method for manufacture of a welded steel pipe wherein the edges of a steel plate bent into a pipe shape are welded together on one side for forming a pipe and then the seam line of the thus formed pipe is welded by a second welding operation at the side opposite to the side where the first welding was performed. During such second welding, the weld is cooled forcedly from the side where the first welding was performed. Such forced cooling compensates for any physical effects accompanying the welding and imparts elevated toughness to both the weld metal and the heat affected zone.

Methods and devices for cutting, eroding, welding and depositing metallic and non-metallic materials by means of an electric arc

Abstract: The trajectory and speed of a turning electric arc in a device for cutting, eroding, welding or depositing material are controlled by varying the voltage and frequency of a polyphase current supplied to pole pieces disposed about the arc. The arc may be formed into a practically continuous bell-shaped or cylindrical sheet, thereby increasing the arc power.

Gas Tungsten Arc Welding

Abstract: Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a nonconsumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by a shielding gas (usually an inert gas such as argon), and a filler metal is normally used, though some welds, known as autogenous welds, do not require it. A constant-current welding power supply produces energy which is conducted across the arc through a column of highly ionized gas and metal vapors known as a plasma.

Oxygen and Nitrogen Contamination during Arc Welding.

Abstract: : The sources, mechanisms, and expected levels of oxygen and nitrogen contamination during gas tungsten arc, gas metal arc, shielded metal arc, self-shielded metal arc, and submerged arc welding are reviewed. Calculations indicating the importance of decomposition of SiO2 into silicon monoxide and oxygen are presented, indicating that silicon transfer between the slag and metal occurs by a gas-metal rather than a slag-metal reaction mechanism. A model suggesting that arc stabilizing additions to fluxes should provide volatile subspecies upon heating is also discussed. (Author)

Reduction of arc blow in multi-electrode welding

Abstract: A method and apparatus for reducing "arc blow" in multi-electrode welding of a metallic workpiece Arc blow is produced by interaction between the magnetic fields produced by the closely spaced arcs and electrodes, and takes the form of the end arcs being attracted inwardly towards the others This reduces the welding efficiency and the maximum welding speed The invention reduces or eliminates the arc blow by providing shunts made of magnetically permeable material close to the arc-producing ends of the electrodes at the two ends of the row of electrodes This reduces the concentration of magnetic flux in these regions and reduces the deviation of the end arcs The invention can be applied wherever multi-electrode welding is used, but is especially useful when the workpiece is made of aluminum as arc blow is a particular problem with this metal

Submerged arc welding process

Abstract: Submerged arc welding process for 3.5% Ni steel which can provide a welded portion having a satisfactory impact resistance at low temperatures such as below minus 100° C. In the process, use is made of a flux having a basicity as defined by a formula (CaO+MgO/SiO 2 ) in weight percentages of between 1.5 and 3. The weld metal is deposited in a plurality of superimposed welded layers, each having a thickness less than 7 mm so that the weld metal in an underlying layer is thermally affected by an adjacent overlying layer whereby recrystallization is effected in substantial thickness of the underlying layer to provide a fine crystalline structure.

Energy beam welding with filler material

Abstract: In automatic energy beam welding, as electron beam welding, of workpiece edges which form a gap of varying width along the weld line, the amount of filler material needed for making up for the volume of the gap is determined by probing the size of the solidified weld bead at a surface of the workpiece and the rate of supply of filler material to the welding zone is controlled on the basis of the result of such determination such that the size is maintained between predetermined limits.

Welding wire for austenitic stainless steel

Abstract: PURPOSE:To manufacture the titled wire excellent in the creep rapture strength at high temperature, and in the creep rapture elongation, by adding a specified amount of each of C, P, V, to the ordinary fundamental constituent of the austenitic stainless steel. CONSTITUTION:The ordinary fundamental constituent of the austenitic stainless steel is Mn <=2.0%, 8-13% Ni, and 18-24% Cr by wt%; to this fundamental constituent, 0.02-0.10% C, 0.01-0.08% P, and V <=0.15%, are added, and moreover, if necessary, 0.1-1.0% Si, Ti <=0.6%, and B <=0.01%, are added; thus prepared constituent is suitable for the austenitic stainless steel wire for use of the arc welding, like as TIG welding, submerged arc welding, MIG welding.

Rollable arc welding trolley, esp. for MIG welding - where trolley contains lead accumulators supplying the welding current

Abstract: Arc welding machine, esp. for inert gas welding, where batteries are used to supply low voltage d.c. via an electric contact to a consumable electrode wire. The batteries are located on a sliding table mounted in a trolley. Two 12 volt batteries are pref. connected in series to provide the welding current, esp. using a frame contg. sockets which can be pressed onto the battery terminals to make a rapid connection. The trolley pref. contains a spool of electrode wire and a wire feeder; and the batteries can be located side by side, or one above the other, in the trolley. The pref. batteries are lead accumulators fitted with a connection for recharging and also driving an adjustable d.c. motor actuating the wire feeder. The protable welding trolley requires no mains electricity connection during welding, and no welding transformer.

Method for electroslag welding of metals

Abstract: A method for electroslag welding of metals whose density is less than thatf welding fluxes, is provided. The method is based on floating-up of drops of molten metal of the edges being welded and of the electrode in a slag whose density exceeds that of the metal. The floating-up metal drops form a metal bath on the surface of the slag bath, and crystallization of the metal bath produces a weld. In the course of welding, the electrode metal is fed into the slag bath in the upward direction, while the electrode metal melts and the weld is built up in the downward direction.

Method of and welding torch for arc welding

Abstract: Plasma-MIG welding in which a thermally ionizable gas stream is flowed through a nozzle non-consumable electrode having a central orifice and a surrounding annular opening 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 then spontaneously established by means of the MIG-arc between the nozzle non-consumable electrode and the workpiece. The central plasma gas column is accelerated by constriction of the annular gas shield downstream of the nozzle non-consumable electrode.

Method and device for welding in a thermally ionized gas

Abstract: A plasma-MIG welding system in which the power for establishing the MIG-arc is supplied to the consumable electrode at a point downstream of the non-consumable electrode.

Oscillating arc welding

Abstract: A welding process, such as a GMA welding process, employs a consumable electrode with the consumable electrode being oscillated back and forth over the surface of an object to which welding material is to be applied or across the gap between two pieces of metal to be welded together. At the ends of the swings of the consumable electrode an impact force is applied to the consumable electrode to interrupt its movement, thereby causing molten metal at the end of the consumable electrode from which the arc is struck to be impelled therefrom.

Welding method for forming thick walled steel pipe

Abstract: PURPOSE: to obtain high quality weld zone excellent in the low temperature toughness at high efficiency, by employing the thin wire with the high current at welding the thick walled steel pipe, by preparing the mixed gas atmosphere from the inert gas added with CO 2 , and by giving a fast fine oscillation to the arc. CONSTITUTION: At welding work for forming the thick walled steel pipe, by first executing the MIG welding for the root layer and then by executing the SAW welding for obtaining the flush weld as the final layer; the mixed shielding gas atmosphere is prepared by adding CO 2 to the main mass of the inert gas, and the thin welding wire of diameter 0.8W2.4mm is employed. The distance l(mm) between the feeding tip and the groove bottom is set at l>10d+5, and the welding current I is set against the wire diameter (d) at the range, 500d≥I≥500d-150. Furthermore, a fast oscillation of frequency 3W30 cycle/sec and amplitude 1W15mm is given to the arc. Hereby, the arc is generated in the state of being throttled to thin and stiffened, the resistance against the magnetic blowout is improved, the directivity of the arc in the direction of wire extension is improved, and the smooth appearance of beads is obtained. COPYRIGHT: (C)1980,JPO&Japio

Gas metal arc welding apparatus for repairing misaligned tube holes

Abstract: A welding apparatus including a nozzle assembly having a contact extension and a contact tip for guiding a consumable welding wire into a tube hole. The consumable welding wire is guided into the tube hole and an electric current is passed to the wire to produce an arc between the tip of the wire and the sidewall of the tube hole, melting the wire and supplying filler weld to the hole. The nozzle assembly has a gas nozzle; and, during the welding process, an inert gas is delivered into the tube hole through the gas nozzle.

Automatic tig welding method of pipe and pipe plate

Abstract: PURPOSE: To achieve the improvement in the toughness of weld heat affected zone and welding efficiency by welding a pipe and pipe plate while cooling the same by the pressure air or the like from the circumference of a welding torch at the time of subjecting the pipe and pipe plate to TIG arc welding. CONSTITUTION: The pipe 1 and pipe plate 3 belonging to a chemical apparatus such as methanol converter or the like are seal welded in a three o'clock welding posture. A welding torch 5 is made in double construction and pressure air, pressure carbonic acid gas or the like is jet out near the weld zone from the circumferential hole at the end of the outer nozzle 11 thereof, whereby the weld zone is cooled. Arc is generated between the welding torch 5 and the corner part of the end faces of the pipe 1 and pipe plate 2 and automatic welding is performed while the wedling torch 5 is being rotated along the circumferential direction of the pipe. According to this method, sound beads 9 are formed without becoming dropping beads. In addition, the weld heat effected zone 10 is suppressed of particle coarsening and the toughness is considerbly improved. Since the quantity of heat input may be increased, the considerably improvement in welding performance may be achieved as well. COPYRIGHT: (C)1980,JPO&Japio

Copper-manganese alloy filler rod - for MIG welding ferrous and non-ferrous metals (OE 15.1.78)

Abstract: The filler rod for arc welding ferrous and non-ferrous metals has the compn. (wt.%) 8.0-38.0 (14.0-38.0) Mn, 0.1-1.0 Si, 6.0-24.0 (6.0-18.0) Ni, 0.5-5.0 Fe, balance Cu, up to 5% Ni may be replaced by Co, Fe may be replaced partly by Cr, Al, Mo, Nb, W and Si, and wholly or partly by Ti, Li and Be. The filler rod may be used with 5.0-14.0% of a known Cu-Al filler rod which is molten in the liquid pool without arcing in the TIG or MIG or plasma arc welding method. For welding Cu-Ni- and Fe alloys, espec. iron castings.

Welding tubular armature tabs using TIG

Abstract: Non-continuous forms are welded on an automatic device using a continuous welding process (e.g., Tungsten Inert Gas Process (TIG) with a continuous welding arc. The noise level of the welding system is below that which is prescribed by the Operational Safety and Health Act (OSHA). The device includes apparatus for indexing and positioning the non-continuous forms relative to the welding electrode. The device further includes apparatus for chilling the non-continuous forms during the welding process, and apparatus for periodically shunting the welding arc away from the non-continuous forms so as to maintain a continuous welding arc.

Charged particle beam welding with beam deflection around weld pool retainers

Abstract: A method and apparatus for charged particle beam welding is provided with a beam deflection mechanism adjacent the surface of the workpiece The beam deflection mechanism permits the use of a welding shoe for retaining a pool of molten material adjacent the point of welding

Tandem system high speed arc welding method

Abstract: PURPOSE:To form an excellent weld bead at high speed, by melting and smoothing the bead surface layer by TIG welding after forming a bead on the steel plate by MIG welding in a shielding gas containing O2 and H2 by specified contents in Ar. CONSTITUTION:While feeding Ar containing O2 by 0.2-2wt% and H2 by 0.4- 4% from a gas feed hole 4 in a trailer shield nozzle 3 as shielding gas, non-oxidation weld bead 7 is formed on a steel plate by means of a MIG welding torch 1 having an electrode wire 2. A TIG welding torch 5 which is connected to said torch 1 in a position behind the same MIG welding torch 1 and has W electrode 6 is moved to the left at high speed, and the surface layer of the non-oxidation weld bead 7 is melted and smoothed by the torch 5. In this method, high-speed welding may be performed stably, and an excellent weld bead free of undercut may be easily obtained.

Plasma welding torch

Abstract: PURPOSE: To provide the subject torch wherein a nozzle part is formed into a flat shape, and a packing is amply separated from an arc heat generating part, thereby to make it possible to carry out welding in a narrow groove and improve the durability of the packing. CONSTITUTION: A torch main body 6 has a tungsten electrode 7, and a copper tube 7a has a cooling water path 8. Further, a gas path 10 is formed between the metal tube and the tungsten electrode 7. A nozzle main body 10a is flat, and fixedly connected to the torch main body 6 by means of a check metal fitting 11. The nozzle electrode 7 has a nozzle hole 12 and is connected to the metal tube 9 by a screw 13. A heat-resisting packing 14 and a cooling water passage 15 hold therebetween the tungsten electrode 7 and are provided at both sides of the tungsten electrode 7 by forming a pair. According to this constitution, since the nozzle part is flat, welding is possible in a narrow groove, and since the packing 14 is amply separated from the arc heat generating part, no damage due to the welding heat is produced and the durability is good. COPYRIGHT: (C)1980,JPO&Japio

Gas shielded arc welding appts. - with connections for hand torch or portable set with separate wire feed

Abstract: In an inert-gas welding set, two plug-in connectors for gas, welding current and wire supply are provided on the wheeled plant housing for the connection of a welding nozzle or of a portable appliance The latter is linked to the plant by a longer connection and has a separate wire feed An additional control cable connects the portable appliance to the main plant This avoids the complications of a wire feed of over 3 m length to remote welding positions and is equally suitable for MIG or MAG welding