Showing papers on "Gas metal arc welding published in 1983"

Arc welding method

Abstract: An arc-welding method, which comprises: arc-welding objects of welding together along the line of a groove formed between said objects of welding by continuously moving a welding electrode along the line of said groove while reciprocating said welding electrode in the width direction of said groove; characterized by: calculating at prescribed time intervals, for each one reciprocation of said welding electrode in the width direction of said groove, deviations (l-lo) of values (I) of one of arc current and arc voltage from a previously set reference value (lo), for each of left-side deviations (L) and right-side deviations (R) relative to the vertical plane which passes through the center of amplitude of said one reciprocation of said welding electrode and is parallel to the line of said groove; calculating at said time intervals, when said welding electrode moves over the left side of said groove relative to said vertical plane, differences (L-R) between said left-side deviations (L) and the immediately preceding right-side deviations (R), to controllably aligning the center of said amplitude of said one reciprocation of said welding electrode with the center of said groove In the width direction thereof at said prescribed time intervals so that said differences (L-R) become null; and, calculating at said prescribed time intervals, when said welding electrode moves over the right saide of said groove relative to said vertical plane, differences (L-R) between said right-side deviations (R) and the immediately preceding left-side deviations (L), to controllably aligning the center of said amplitude of said one reciprocation of said welding electrode with the center of said groove in the width direction thereof at said prescribed time intervals so that said differences (L-R) become null.

Welding method combining laser welding and MIG welding

Abstract: Welding of deep penetration is obtained in a sustrate by a method which comprises first melting the joint portion of the substrates by MIG welding and then focusing a laser beam in the bottom surface of a crater formed in consequence of the MIG welding thereby effecting laser welding of the crater.

Gas metal arc welding method

Abstract: A gas-metal-arc welding method is provided for high speed, high melting rate, substantially spatter-free, all-position welding. The method is particularly useful for out-of-position welding, that is, to produce vertical, inclined and overhead welds. A consumable wire electrode is held within and fed through the tubular contact tip of a continuous feed type welding gun having a tubular nozzle surrounding and extending beyond the tip. A shielding gas, formed of unique ratios of a minor proportion of a carbon dioxide and oxygen mixture combined with a major proportion of an argon and helium mixture, is flowed in a substantially longitudinally laminar pattern between the nozzle and contact tip and along the electrode extension from the tip. The contact tip is cooled, and sufficiently high power electrical current is passed through the contact tip and electrode extension to produce the arc and to melt the end of the electrode into molten drops for short-circuiting (e.g., low current) or for spray (e.g., higher current) transfer of the drops to the weld deposit. The electrode extension is pre-heated by maintaining a long electrode extension or stick-out beyond the contact tip end, with a substantial portion of the extension recessed within the nozzle.

Electrical resistance-pressure welding process for welding parts of workpieces made of aluminum materials and an apparatus and electrode therefor

Abstract: Spot- and projection-welding of aluminum sheets has always been connected with difficulties mainly because of the surface layers of aluminum oxide, and even by pickling, these difficulties could be only partly eliminated. The main difficulties have always been insufficient electrode life times, the unsatisfactory quality of the weld and especially the unsolved problem of achieving good quality welding and long electrode-life when using un-pretreated aluminum sheets. The problem has been solved in principle by using electrodes having profiled contact-surfaces, by means of which the layer of oxide is broken during pre-pressing and a direct contact between the electrode and unoxidized material of the workpiece is provided, the contact-resistance of which is lower than the portion of the overall resistance of the point of weld formed by the metal of the aluminum sheets to be welded together. In an appropriate welding machine, the means for switching-on the welding current are controlled in such a manner that the welding current is switched on only after a sufficiently large contact area and therewith a sufficiently low contact-resistance of this contact has been reached.

Thermally assisted ultrasonic welding apparatus and process

Abstract: Method and apparatus are provided for use in an ultrasonic vibratory welder for pre-heating the workpieces prior to welding and, thereafter, for continuously monitoring the temperature of the anvil and of the welding tip during subsequent welding operations to insure their temperature remains within a pre-determined range during the entire welding cycle. It has been found that weld characteristics, particularly weld size, shape, configuration and strength are dependent upon the temperature of the anvil and welding tip. Thermostatically controlled resistance heating means are provided in the anvil and/or in the welding tip for pre-heating of the workpieces. Automatic control means, are also provided for alternately heating and cooling the anvil and welding tip during the welding cycle.

Spectroscopic measurement of hydrogen contamination in weld arc plasmas

Abstract: The introduction of hydrogen into metals during welding is known to cause hydrogen assisted cracking and embrittlement in certain situations. It has been shown that the weld metal hydrogen content is directly related to hydrogen concentration in the weld arc plasma. In this paper we describe a simple spectroscopic technique for measuring the arc plasma hydrogen concentration in real time when an argon shield gas is used. This technique is based on the fact that the intensity ratio of the hydrogen Balmer Alpha emission line at 6563 A and an argon emission line at 6965 A was observed to be an approximately linear function of hydrogen concentration in the weld arc plasma. This technique was experimentally verified under a variety of welding conditions for gas metal arc welding and found to have an error of less than 10% when measuring hydrogen concentrations in the arc plasma as low as 0.25% by volume. This method of hydrogen measurement is also applicable when welding with shield gases not containing argon so long as a suitable ratioing line is available.

Arc welding torch with integral vision sensor

Abstract: A gas tungsten arc welding torch has an integral optical system which images the weld puddle on the face of a fiber optic cable, and is suitable for industrial welding. The copper torch body has cover gas, electrical power, and coolant connections and an integral slim profile electrode holder. The optical lens is located directly above the electrode; the holder is out of focus and is not seen in the image of the weld region. A concentric torch configuration is more compact and has a large field of view at the weld area. When coupled to a remote video camera and monitor components, the torch-vision system permits control of torch manipulation and of the weld process.

Resistance welding of zinc-coated steel

Abstract: A method for resistance welding zinc-coated steel members is described wherein at least one member comprises a copper layer intermediate the steel and the zinc coating. The copper layer melts during welding and seals fissures within the fused steel to produce a hermetic weld. The copper layer also protects exterior surfaces where the zinc coating is disrupted by the welding operation.

Flexible trailing shield for welding reactive metals

Abstract: A flexible trailing shield for providing nonreactive gas shielding to arc lding operations comprises a housing formed of interlocking transverse segments adapted to flexibly cover weld surfaces having varying configurations. The housing has a torch entrance port for slidably receiving a welding torch, a conduit for receiving gas into the housing, a foraminous material to uniformly distribute the gas within the housing, and a pervious structure through which the gas is dispersed over the weld surface.

Welding Under Water and in the Splash Zone — a Review

Abstract: The author reviews the parameters controlling underwater welding especially arc welding with covered electrodes, MIG, TIG and with cored wire. It describes wet welding and hyperbaric welding, with the use of nitrogen and noble gases for shielding and in the welding chamber. The specific problems of underwater welding are described in detail: hardness of the HAZ, cold cracking by hydrogen, method of calculating the thermal input, consequences of pressure on fusion characteristics.

Flux cored stainless steel wire

Abstract: PURPOSE:To provide a titled wire which welds satisfactorily and highly efficiently a high-nitrogen stainless steel wire by filling a wet water glass mixture composed of a slag forming material and deoxidizing agent having specific components and weight ratios into a stainless steel pipe and maintaining the nitrogen content of the entire part including the pipe at a specific value. CONSTITUTION:A slag forming material consisting, by weight ratios in terms of the individual components incorporated therein, of 0.001-0.1% S, 0.001-0.3% Bi, 0.1-10% TiO2, 0.1-7% Si; O2, 0.1-5% ZrO2 and a deoxidizing agent contg. 0.5-3% in total of Si, Ti, Al and Mg are wet mixed with water glass and the mixture composed thereof is filled into a stainless steel tubular wire. The nitrogen content over the entire part of the flux cored wire is made 0.05-0.4wt% of the entire part. If a high-nitrogen stainless steel is subjected to MIG welding by using such wire, the high-nitrogen stainless steel is welded with good slag detachability by the synergistic effect of the elements regardless of the kind sheet thickness and groove shape of the steel and the welding operation is made safe, good and highly efficient.

Method for welding very low carbon steel

Abstract: A method for arc welding a very low carbon steel containing 0005-006% C characterized by employing a welding material with nickel together with high carbon so as to form weld metal containing nickel Solidification cracking on the thus welded metal can be prevented

Method for measuring the free wire length in MIG/MAG welding

Abstract: The present invention relates to a method for measuring the free wire length in hot-arc or short-arc MIG/MAG welding by making use of the typical behavior of the current or the voltage in the bead short-circuit situation, in which the voltage rises in different ways depending on the free wire length. The phenomenon can be used for measuring the free wire length.

Method for welding by magnetically driven arc

Abstract: A method for welding by a magnetically driven arc, which comprises placing two objects of welding in butt formation with a small gap between the end edges thereof to form a welding line; parallelly connecting a first electric circuit comprising the two objects of welding and a cable arranged on the surface side of the two objects of welding and a second electric circuit comprising the two objects of welding and another cable arranged on the back side of the two objects of welding to a welding power source; flowing a welding current through the first and second electric circuits to produce an arc in the small gap; moving the arc along the welding line under the effect of an electromagnetic force in the direction of the welding line, the electromagnetic force being produced by the magnetic flux of magnetizing coils provided near the end edges of the two objects of welding and welding current flowing through the arc; and changing the amount of welding current flowing through the first and second electric circuits to control the electromagnetic force in the thickness direction of the two objects of welding; thereby continuously moving the arc in the thickness direction of the two objects of welding, thus uniformly heating the end edge of the two objects of welding to a welding temperature by the heat of the moving arc.

Process Variables and Properties of Underwater Wet Shielded Metal Arc Laboratory Welds

Abstract: Hydrogen pick up and HAZ hardness increase with coating thickness of rutile electrodes in underwater wet SMA welding but decrease with heat input. Multilayer welding of 15 mm thick, 0,14 % C, 0,90 % Mn grade D-steel, provides weld metal CVN-toughness of 35–40 J at 0 °C, applying a total of 14–15 low heat input stringer beads.

Method for welding expanded aluminum member to aluminum die casting member

Abstract: PURPOSE:To join by MIG welding an aluminum die casting part and an aluminum expanded member with good airtightness by improving a casting method for the aluminum die casting part as well as the joint construction of the aluminum expanded member to be welded thereto and the moving locus of a welding wire. CONSTITUTION:An aluminum die casting part 2 is cast in such a way that the content of gas in at least the MIG weld zone thereof decreases. An aluminum expanded part 3 is then matched with the MIG weld zone and both parts 2, 3 are placed in such a positional relation that the surface 29 of the expanded part is placed nearer the MIG torch 31 side than the surface 30 of the die casting part. A welding wire from an MIG torch 31 is moved near the outside circumferential edge of the part 29 and on the surface side thereof by which the parts 2, 3 are welded.

Shielding gas for electric arc welding

Abstract: A shielding gas for use in electric arc welding is disclosed. The gas comprises a mixture of helium, argon, 1.75% to 2.25% carbon dioxide and 0.25% to 1.0% oxygen (by volume). Use of the gas enables slag-free welds which accept readily paint applied by an electrostatic deposition process.

Gas metal arc welding torch with vision system

Abstract: A gas metal arc welding torch has an integral optical system which images the weld puddle on the face of a fiber optic cable. A concentric torch configuration is disclosed having a slim profile filler wire guide that is removably mounted on the ring-shaped torch body and projects into the gas cup at an angle to the optical axis to minimize obstruction of important regions of the weld scene. The fiber optic cable is coupled to a video camera and a viewing system or controller; real time observation of the weld area is made and used to control the weld process.

Build-up welding method

Abstract: PURPOSE:To perform easily build-up welding of cupronickel having excellent corrosion resistance onto the surface of a steel plate by MIG welding with excellent wire feeding performance and good adhesive by using a stranded wire having a specific construction in said build-up welding. CONSTITUTION:A stranded wire 1 constituted in the following way is used in place of a solid wire in the stage of build-up welding of cupronickel having excellent corrosion resistance by MIG welding onto the surface of a steel material to be used in a highly corrosive atmosphere. The stranded wire 1 formed by placing a cupronickel wire 2 of a large diameter at the center and disposing plural pieces of stranded wires 4 each consisting of seven Ni wires 3 made into the small diameter to permit easy melting on the outside circumference of said wire or disposing plural pieces of the stranded wires enclosing Ni powder 5 with plural small-diameter Ni wires 6 is used. Such stranded wires has the property to pass smoothly in the conduit tube pf the MIG welding machine and after the Ni in the small diameter wires or the powder is first melted, the cupronickel is build-up welded, by which the adhesion to the steel plate is improved.

High-frequency arc striking device and auxiliary electrode of an electric welding or cutting arc

Abstract: A high frequency-high voltage generator supplies current, on one hand, to a first arc striking circuit connecting a main electrode to an auxiliary electrode and, on the other hand, to a second arc striking circuit which connects one of the two electrodes to the workpiece to be treated. In this way there is achieved a striking of the arc in two stages. This ensures high reliability regardless of the nature of the material from which the workpiece is made regardless of the protecting gas used, in particular for the TIG welding of light alloys in a helium atmosphere. The device is applicable to an automatic TIG welding.

Joining method of aluminum-titanium by arc welding

Abstract: PURPOSE:To obtain a defectless joint part by combining specifically a welding power source, heat source, shielding gas and welding rod or electrode wire so that only the Al base metal side and welding rod are melted and that the Ti base metal side is hardly melted. CONSTITUTION:An arc 5 is generated between an electrode 6 of a torch 7 and base metals 1, 2 for the butt parts of the base metal 1 consisting of an Al alloy and the base metal 2 consisting of Ti. The TIG arc by a DC power source of a straight polarity or AC power source AC as a welding power source P or the MIG arc by a DC power source of a reversel polarity is used as a heat source for the arc 5. Al or the alloy thereof, phosphor copper solder or silver alloy contg. >=20% (by weight) Al is used as the welding rod or electrode wire. Gaseous Ar 8 is used as the shielding gas. The weld metal 3 formed in the joint parts between the base metals 1 and 2 has the compsn. in which the Al base metal 1 and the welding rod 4 are mixed.

Welding method of copper to iron or steel

Abstract: PURPOSE:To weld copper to iron or steel easily and securely without inducing hot cracking or the like by using a nickel as a welding material. CONSTITUTION:Copper and mild steel 2 are welded directly by using nickel 3. The welding may be any among arc welding with covered electrode, MIG welding and TIG welding, by which the nickel is solutionized to both of the copper and the iron or steel and the welding is accomplished extremely satisfactorily without requiring highly advanced welding techniques. If the copper 1 is welded to the steel 2 by the nickel 3 after the nickel is underlaid 4 in the groove of the copper 1, the easier welding is made possible.

Method of hardfacing vertical walls

Abstract: A method of hardfacing vertical walls comprises building up a layer of superimposed partly overlapping horizontally extending weld beads by depositing the beads in a submerged arc welding operation using relatively thin welding wires and welding powder which is fed over the weld wire. The welding powder is allowed to accumulate to provide a support for additional powder as welding progresses vertically.

CO2 laser welding of deep drawing steel sheet and microalloyed steel plate

Abstract: High power laser welding has been examined in two fabrication areas for which it is particularly attractive: high speed welding of sheet for the mass production industries, and deep penetration welding of plate for heavier fabrications such as pipelines and ships. Using a 5kW laser, welding trials have been conducted to determine weldability lobes for 2,3 and 4mm thick deep drawing steel. For thicker sections, a technique to allow more efficient welding (plasma control) is described, and the results of impact testing of welds in a 12.5mm thick C-Mn-Si-Nb-Al structural steel are given. In addition, the feasibility of using wire feed with laser welding to fill a joint gap or to alter weld metal composition is discussed.

Ni-containing wire for mig arc welding of low temperature use steel

Abstract: PURPOSE:To obtain high toughness by adding a specific amt. of a rare earth element, Al and B to a titled wire and using pure gaseous argon as a shielding gas thereby decreasing the content of oxygen in the weld metal and forming the finer structure. CONSTITUTION:A rare earth element is added at 0.02-0.30wt% to a titled wire to stabilize an arc and Al is added thereto at 0.010-0.080wt% and B at 0.0004- 0.0015wt% to form the finer structure. The wire for pure gaseous argon shielded MIG arc welding for low temp. use steel contains, by weight %, <=0.05% C, 0.1- 0.60% Si, 0.4-1.5% Mn, 2-6% Ni and 0.05-0.25% Mo as the other components and consists of the balance Fe and unavoidable impurities.

Underwater Dry TIG Welding Using Wire Brush Nozzle

Abstract: In an underwater dry welding in a deep water, mixed gas of helium and oxygen is used as the environmental atmospheric gas and to reduce the fume and the spatter, the most suitable welding method is TIG welding. However the helium gas as the shielding gas has such drawbacks as tungsten electrode is eroded seriously and arc-starting is difficult in high pressure, while argon gas is superior to helium gas in the said characteristic but argon is about twice as narcostic as nitrogen, thus a special wire brush nozzle which consist of dual nozzle was developed: Argon was flowed out from a inner nozzle and the gas was inhaled by a vacuum pump from a circular gap between the inner nozzle and the outer nozzle having wire brush which prevented to leak the argon to the environmental atmosphere. With this nozzle as the result that inhalation ratio is selected 2.0 under the current of 200A, satisfactory welds could be obtained even in a water depth of 200m and welding could be done comparatively in long time under the condition that the shielding gas and the fume did not leak to the environmental atmosphere.