Showing papers on "Gas metal arc welding published in 1982"

Numerical analysis of thermal stresses during welding including phase transformation effects

Abstract: The problem of determining temperature distributions, transient thermal strains, and residual stresses during butt welding thick plates with the multipass GMAW process is solved using the finite element method. First, a nonlinear heat transfer analysis is performed taking into account the temperature dependence of the material properties, and convection and radiation surface heat losses. This is followed by a thermo-elastic-plastic stress analysis that incorporates phase transformation strains. Finally, the theoretical predictions are compared with experimentally obtained data showing good correlation.

Process for the production of a composite metal part and products thus obtained

Abstract: The present invention relates to the production of metal parts whose core and surface must have different characteristics. Its subject comprises firstly a process for the production of a composite metal part by coating or hard-surfacing a metal core of low-alloy structural steel with a harder metal layer composed of a high-speed chromium-tungsten or chromium-molybdenum steel or a high-speed steel containing chromium associated at the same time with a plurality of elements such as tungsten, molybdenum, vanadium, and cobalt, this process being at the same time characterized in that this high-speed steel has a hardness higher than 57 Rockwell C, in that the low-alloy steel which constitutes the metal core is selected to be compatible with the said high-speed steel, in that the said high-speed steel is applied exclusively in the form of a prealloyed powder, and in that the coating or hard-surfacing of the core with this powder is effected with the aid of one of the welding processes of the follow-group: welding by means of a transferred or semi-transferred arc plasma torch, or welding by means of a laser torch, the operation of coating or hard-surfacing by welding being followed by heat treatment. Another subject of the invention comprises the products obtained by the abovedescribed process. It is particularly applicable to the production of rolls for cold rolling mills, rolling or forming rollers, shear blades, wear plates, and armor plates.

Controller for arc welding robot

Abstract: PURPOSE:To eliminate the laboriousness of teaching and to improve the working efficiency of welding by the constitution wherein only the control commands of specific operations except the common operations of welding modes in an arc welding robot are taught to the robot CONSTITUTION:In the case of MIG welding, if welding conditions for the time T1 until a robot body operates and a crater treating time T2 are inputted by shifting an external selecting switch 32 to an MIG welding position, a current command and a voltage command are outputted to a welding power source 4 from an apparatus control part 23 In the case when WIG welding is required, the timers necessary for welding sequence are T1 and T2 as well as a timer T3 until a wire is fed, and the teaching of the positions and attitude information as well as other welding conditions may be the teaching which is beforehand inputtedThus all required for the operator is to shift the switch 32 to a TIG welding position and to teach only the T1, T2 and T3 Thereupon a current command and a wire feed command are outputted from the part 23 to the power source 4 according to the welding sequence

A new approach to the weldability of nickel-base As-cast and power metallurgy superalloys

Abstract: The repair of nickel-base superalloys such as those used in the first and second stages of the rotating sections of a gas turbine is examined. Welding is affected by stress and temperature levels of the blade, wall thickness, and material composition. Steps to achieve crack-free welds include preheating above 600C (1112F) for GTA and plasma arc welding and above 900C (1652F) for EB welding. It is concluded that crack formation can be prevented by controlling the cooling rate during welding; that hardness measurements provide useful results for crack-free welding using GTA, plasma, friction, and electron beams; and that small differences in chemical composition and homogeneity can have a decisive effect on weld behavior.

Method of welding titanium alloy parts with titanium insert

Abstract: A method of welding opposite end surfaces of two titanium alloy parts kept in alignment by a high energy-density welding process such as electron beam welding, laser beam welding or TIG arc welding, characterized by closely interposing an insert member of either practically pure titanium or Ti-Al binary alloy containing up to 3 Wt % of Al. Owing to thorough alloying of the inserted titanium with the constituents of the fused base metal, the weld metal in a weld joint obtained by this method is sufficiently high in both strength and toughness. By an optional postwelding heat treatment, the strength of the weld metal can further be enhanced.

Tubular composite arc welding electrode for vertical up welding of stainless steel and nickel-base alloys

Abstract: In a tubular composite electrode for depositing stainless steel or nickel-base alloy weld metal, satisfactory performance in vertical up welding is achieved through the inclusion in the electrode core of a slag mix comprising 15 to 60% weight percent zirconium dioxide.

Consumable electrode type arc welding device

Abstract: PURPOSE:To provide a titled welding device which improves welding performance and the efficiency in welding work by the constitution wherein the waveform of welding current is pulsed to form a spray arc and a separate filler wire is fed under electrical heating into the arc. CONSTITUTION:Welding current is flowed from a power source 24 through a tip 16 to a consumable electrode 10, which is fed by a roll 12 driven by a motor 14, to generate an arc 20 between the electrode and a base material 60. The adequate pulse waveform corresponding to the feed speed of the electrode 10 is formed in the welding current by a frequency setter 46, a pulse width setter 48 and a switching element 34 to make the droplet from the electrode 10 into a spray. A filler wire 26 is at the same time fed into the arc 20 while it is heated by part of the welding current supplied from a power feeder 32 to adjust the penetration rate of the molten metal. The heating current for the wire 26 is controlled by a frequency setter 46, a pulse width setter 50, a current comparator 59, a switching element 36, etc. so that said current is kept at <=1/2 of the welding current and is made zero during the quiescent period of the pulse.

Semi-automatic control and method for MIG welding

Abstract: A method for controlling selected switching between preset welding schedules in a MIG welding operation, in response to operation from a single control switch having only on and off signal selections.

Tig welding method of narrow groove

Abstract: PURPOSE:To make an arc oscillatable in the transverse direction of a groove and to perform stable penetration in the TIG welding stage of a narrow groove joint of extra thick plates, by forming an electrode and a filler metal respectively into a band shape, and applying an alternating magnetic field in the weld line direction to the arc. CONSTITUTION:A nonconsumable W electrode 4 screwed 3 to a copper electrode nozzle 2 is formed into a band shape and a filler metal 10 to be supplied to an arc 11 part by passing through the inside of a filler nozzle 8 of a gas shielded nozzle 6 is also formed into a band shape in TIG welding in the narrow groove between groove wall surfaces 19 and 19. A magnetic core 12 of which the forward end passes through a gas shielded nozzle 7 and extends to the part near the arc 11 is connected to the magnetic pole of an electromagnet coil 13. The arc 11 is oscillated in the transverse direction by the alternating magnetic field generated from the core 12 and the narrow groove of extra thick plates is welded in the joint part having high quality by using the bank-like filler metal.

Welding method of tempered type steel pipe

Abstract: PURPOSE:To obtain a welded steel pipe having high tensile strength and low temp. toughness, by tempering the same under limited conditions under submerged arc welding by a wire of the specific compsn. consisting of C, Si, Mn, Ni, Cu, P, S, Fe, etc. and a flux having specific basicity. CONSTITUTION:A steel pipe is welded by submerged arc welding by using a welding wire consisting of 0.05-0.15% C, =1.5, more preferably about 1.5-2.5 basicity B expressed by the equations. The welded steel pipe is quenched after heating to 900-1,100 deg.C and is then tempered for >=5min at 600-700 deg.C, whereby the welded steel pipe having the weld metal of high low temp. toughness wherein the Charpy transition temp. is about =50kg/mm. is obtd.

Development and Application of Dabber Gas Tungsten Arc Welding for Repair of Aircraft Engine, Seal Teeth

Abstract: Dabber TIG welding can be defined as a modification of an automatic TIG welding system. Modifications, both mechanical and electronic, combine to cause an intermittent filler wire feed to the molten weld puddle. This interrupted action allows for momentary cooling of the weld puddle. Energy input, as heat, for a given time span is reduced by this action. In addition the interruption allows solidification of the puddle with resultant narrow, uniform bead. This weld mode is characterized by shallow heat affected zones and precise weld build up configurations. This paper describes the application of this procedure to Gas Turbine Seals.Copyright © 1982 by ASME

Welding process for applying a hardfacing to a nodular iron base metal

Abstract: A hardfacing 16 is applied to a nodular iron base metal 15 without preheating or postheating the base metal. Initially a gas tungsten arc welding torch is applied to the base metal (at ambient temperature) to form a puddle of the base metal. Then a filler metal, e.g. a high chromium iron. is fed into contact with the arc to form a melt of the filler metal on the base metal. The base metal is then allowed to cool to ambient temperature with postheating.

Electro-slag welding process for irregular sections

Abstract: An electro-slag welding method and apparatus has been developed for butt-joint welding of steel rails or other metallic pieces having irregular cross section, in which the head and the web of the rail is surrounded with a conventional water cooled copper mold and the flange area is surrounded by a ceramic lined crucible. In addition to the conventional single central welding electrode, two or more electrodes are inserted through the lids of the ceramic crucible adjacent the outer ends of the rail flange so as to reduce the total welding current required to produce a complete flange weld and spread the welding energy, thereby reducing excess power and overheating at the central electrode, resulting in better metallurgical quality welds.

Method and system for automatically terminating a MIG welding operation

Abstract: A method and control circuit for terminating a consumable electrode electric arc welding operation which comprises monitoring the welding parameters of the wire drive motor speed and the arc working voltage, comparing the monitored levels with a multiple number of present combinations of both arc working voltage and motor speed with at least one preset combination defining a high arc working voltage representing a long arc condition and with the last preset combination including a motor speed of relatively close to zero; evaluating each preset combination in tandum to determine if the conditions of a preset combination are satisfied and interrupting the power supplied to the arc in response to the satisfied combination of preset conditions

Hot wire welding system

Abstract: A hot wire welding system including a non-melting metal electrode, a supply of filler metal to be fed to a weld puddle formed by an arc, a D.C. power source for supplying both an arc current and a filler metal heating current, a first control circuit for controlling the filler metal heating current with a constant voltage characteristic, and a second control circuit for controlling the arc current with a constant current characteristic. By eliminating one of the two power supplies which was required in prior art systems, a significant reduction in size and complexity is obtained.

High-power laser and arc welding of thorium-doped iridium alloys.

Abstract: The arc and laser weldabilities of two Ir-0.3% W alloys containing 60 and 200 wt-ppm Th have been investigated. The Ir-0.3% W alloys doped with about 60 wt-ppm Th are used as post-impact containment material for radioactive fuel in thermoelectric generators that provide electrical power for outer planetary missions. 18 refs.

Hot wire type arc welding system

Abstract: In a welding apparatus employing a switching element between a power source and a filler wire, a protection circuit operates to discontinue the function of the switching element when a short-circuit is detected between, for example, the filler wire and a welding electrode, so that the switching element is protected from damage due to an overcurrent.

Butt welding method of high purity ferritic stainless clad steel

Abstract: PURPOSE:To obtain a welded joint part which is excellent in both corrosion resistance and a mechanical property, by welding a base metal part of clad steel with a same metal, subsequently, performing butt-welding on a cladding member by a build up welding according to a low dilution welding method by use of a welding rod having the same composition as a cladding material. CONSTITUTION:In case of welding of clad steel whose cladding material is high purity ferritic stainless steel containing 16-21wt% Cr and 0.75-3.5wt% Mo, the same metal welding of a base metal part is completed, and thereafter, a cladding member is butt-welded by building up to >=2 layers in accordance with a low dilution welding method by use of a welding rod having the same composition as the cladding material. As for welding of said cladding material, if necessary, the first layer is welded by a ferritic stainless steel welding rod containing 25-33wt% Cr and 0.75-3.5wt% Mo, and the residual part is welded with a same material or the first layer is welded by a welding rod having the same component as the cladding material, and therefore, said welding can be executed, as well.

Highly tenacious ac mig welding method

Abstract: PURPOSE:To obtain a welding metal superior in tenacity at a low temperature, by making prescribed conditions for the shield gas composite consisting essentially of inert gas and the combination of wire components. CONSTITUTION:A shield gas atmosphere is obtained by mixing 0.5-20% carbonic acid gas and/or 0.1-5% oxygen and rest inert gas. A steel wire having component parameters 0.7-1.9% P, 0.005-0.15% Ti, 0.0005-0.015% B, 0.01- 0.3% C, <=0.6% Si, <=2.5% Mn, and rest Fe which satisfy expression is used. Welding is performed with a welding current of AC 150-1,500A. Thus, a welding metal superior in tenacity at a low temperature is obtained.

Process for welding metal articles

Abstract: A method of welding metal articles along a joint using a non-overhanging torch, for example so called butt welds in a vertical or upright position, of the kind which uses a pulsed arc with gaseous protection and a cored wire electrode, is characterized by use of the following combination: (a) the "pulsed" arc is of the constant frequency pulse type with transfer of molten material at each pulse, without setting up any short circuit, viz. of the "spray arc" kind and (b) the cored wire electrode is of the basic kind.

Flux cored wire for submerged arc welding

Abstract: PURPOSE:To perform welding with easy start of arc and high stability of arcs at a high rate of deposition by using a flux cored wire of a specific compsn. contg. stainless steel powder in submerged arc welding of stainless steel. CONSTITUTION:A flux of the following compsn. is packed in a stainless steel hollow wire of the same material as the stainless steel to be welded as a flux cored wire to be used in submerged arc welding of stainless steel: A flux which contains 0.5-20% 1 or >=2 kinds among rutile, ilmenite and zircon sand by weight of the wire, 0.05-3% 1 or >=2 kinds among potash feldspar, silica and wollastonite, 0.2-5% 1 or >=2 kinds among calcium carbonate, lithium carbonate and barium carbonate, 0.3-2% fluorides such as CaF2 and wherein stainless steel powder is so mixed at <=25% ratio that weld metal and the materials to be welded have the same compsn.

Pulse arc welding method and device

Abstract: A pulse arc welding device includes a power source which produces a background current and pulse current imposed on it. A voltage drop across the arc is measured and when such a voltage drop deviates from a predetermined level, either one of background current, frequency of the pulse current and pulse duration of the pulse current ist controlled to maintain the voltage drop across the arc constant.

Multielectrode submerged arc welding method

Abstract: PURPOSE:To form a weld bead of deep penetration at low heat input and to improve the shape of the bead, by providing a suitable back step angle to a preceding welding core wire and a succeeding welding core wire and supplying a filler wire into a molten pool from the final succeeding welding core wire. CONSTITUTION:Welding core wires 1, 2, 3 into which electrode tips are inserted are supplied into the powdery flux F which is sprayed beforehand on a base material A, while the wires are disposed in tandem. 10-30 deg. back step angle alpha is given to the preceding wire 1 among the wires 1-3, 3-20 deg. back step angle beta is given to the succeeding wire 2 and further, a forward angle gamma is given to the succeeding wire 3. Arcs are generated between the forward ends of the wires 1, 2, 3 and the material A, and the material A is moved in the arrow direction whereby the material A is melted successively and a molten pool C is made. The molten pool is solidified successively to form a molten metal B, by which a weld bead is obtained. The intrusion of the molten metal increased by the melting of a filler wire 4 into the part right under the arcs is prevented and the disturbance of the melting of the material A by the molten metal is thus prevented. The decrease in the penetration depth is obviated even if the wire 4 is supplied from backward.

Mig welding method

Abstract: PURPOSE:To obtain sound weld zones with a simple method in an MIG welding method for a copper material and a steel material by preheating the copper material alone beforehand with the TIG arc. CONSTITUTION:In the stage of welding, for example, a copper sheet 5 of about 2-3mm. thicknesses and a steel material 4 of about >=10mm. thickness, a TIG torch 2 for preheating and an MIG welding torch 3 are disposed along the weld direction A. Here, the aiming positions of the torches 2, 3 are both deviated slightly to the sheet 5 side so that the preheating of the material 4 is prevented. The arc is generated from the torch 2 and only the sheet 5 is preheated by the thereof, after which both materials are MIG welded with the torch 3. Since the sheet 5 can be preheated uniformly, the lack of penetration can be prevented, and since it does not oxidize during the preheating, the generation of blowholes is prevented as well. The welding device to be used is the one provided with, for example, a shielding box 1 displosed therein with torches 2, 3, in which gaseous Ar flows and ejects in the weld zone direction through many holes 1a to put the preheating and welding places in an Ar atmosphere.

Mig welding method of pipe

Abstract: PURPOSE:To generate no welding defect in each end part, by welding the end part of the upstream side and the downstream side in the weld advancing direction, by each welding condition which is different from that of the center part, when MIG-welding the butt part of an open pipe. CONSTITUTION:When welding the butt part of an open pipe formed by bending a plate material by means of MIG welding, it is executed as mentioned below. That is to say, the end part of the upstream side in the weld advancing direction is welded under the welding condition which is set so that welding voltage is higher, and a welding current and a welding speed are smaller, than the welding condition of the center part of the open pipe. On the other hand, the end part of the weld advancing downstream side is welded under the welding condition which is set so that the welding voltage is lower, and the welding current and the welding speed are smaller, than the welding condition of the center part. According to this method, it is possible to prevent generation of a welding defect such as stubbing or humping, etc. in the end part of a pipe.

One side welding method for low temperature steel material

Abstract: PURPOSE:To make good penetration beads formable despite the presence of tack weld beads in particular by forming tack weld beads to a linear shape by MIG welding of low heat input, then performing welding in such a manner as to form penetration beads from the top layer of these tack weld beads by the welding of the next layer. CONSTITUTION:The 1, 1' in the figure are materials to be welded, 2 is a backing strip such as copper plate 3, is a backing strip consisting of flux or glass fiber provided between the bottom surfaces of the materials 1, 1' and the plate 2. The method of this invention first involves forming linear tack weld beads 4 by MIG welding of low heat input. Next, next layer beads 5 are formed by large current MIG welding from the top layer of these tack weld beads 4. The beads after the beads 5 may be formed by submerged arc welding other than large current MIG welding. As a result, the welding for forming the next layer beads is accomplished by making welding current constant, and therefore the stability of the arc is good, and the occurrence of defects in the penetration beads in the tack welded part and near the same as in the prior art is obviated, thus the one side welding of low temperature steel materials is accomplished in a good state.

Process for soldering or welding components produced from not readily joinable metals, in particular for the welding of molybdenum foil current leads and tungsten electrodes employed in the light-source industry

Abstract: The invention relates to a process for soldering or welding not readily joinable metals, which involves, prior to soldering or welding, employing a contact metal between the faying surfaces of the components to be welded or soldered, the contact metal being applied to the faying surface by vacuum evaporation or by cathode sputtering. The process is particularly suitable for the welding of molybdenum foil current leads and tungsten electrodes employed in the light-source industry, but it can also be used advantageously in other fields.