Showing papers on "Shielding gas published in 1980"

Composite wire for gas shielded arc welding

Abstract: PURPOSE: To execute vertical up welding with high efficiency and to obtain the composite wire which has the good migratability of droplets and decreases the amt. of the spatters to be generated by specifying the grain size constitution, incorporating TiO 2 at a specific ratio into the wire and incorporating specific components at specific ratios therein. CONSTITUTION: A flux is filled in the sheath made of a steel. The grain size constitution is so specified that the particles having the grain size exceeding 149μ are incorporated into the wire at 10wt.% and the particles having 44μ grain size or below at ≤30wt.%. The TiO 2 is incorporated into the wire at 3.5W7.0wt.% of the total weight of the wire. Further, contains 0.4W1.0wt.% ZrO 2 , 0.1W1.0wt.% Al 2 O 3 , 0.3W1.0wt.% Si, 1.2W3.2wt.% Mn, 0.1W0.6wt.% Al, 0.03W0.3wt.% total of 1 or 2 kinds of Na, K:Na, K, and 0.01W0.2wt.% F. The vertical up welding is thereby executed with high efficiency and the amt. of the spatters to be generated is decreased; in addition, the working efficiency of welding is improved. COPYRIGHT: (C)1989,JPO&Japio

Hot Cracking Resistance of Austenitic Stainless Steel Weld Metals Increasing Mn and Mo content and avoiding multiple thermal cycles on weld metal HAZ can reduce hot cracking tendency of fully austenitic stainless steel weld metals

Abstract: The fissure bend test origi­ nally developed and evaluated for determining the cracking resistance of SMA deposited austenitic weld metals has been extended to evaluate GTA and GMA deposited filler metals. Fis­ sure bend tests were run on several commercial fully austenitic and ferrite- containing stainless welds deposited by GTA, SMA and GMA welding pro­ cesses. The fully austenitic filler metals are basically AISI Type 310 or 316 com­ position with a difference in the alloy­ ing elements Mn, Mo, and C. The effect of nitrogen additions to the shielding gas, in the GTA process, on the ferrite content of the deposited weld metal has been defined. The nitrogen addition technique shows that it is an effective way of reducing and/or controlling ferrite content. Further, that nitrogen additions have relatively little effect on fissuring ten­ dency in the materials evaluated. In fact, it was possible to reduce the ferrite content from 5 FN to 0.5 FN and maintain fissuring resistance. The nature and morphology of the fissuring in fully austenitic stainless steel weld metals is similar to that of the partially ferritic weld metals. The location, extent and magnitude of the cracking is dependent upon procedure characteristics as well as composition. The weld metal heat-affected zone thermal history plays an important role in controlling fissuring tendency in the fully austenitic weld metals. This effect has been evaluated using a multiple thermal cycle technique in the fissure bend test.

Method and apparatus for the control of shielding gases used in power laser processes

Abstract: In order to remove the plasma cushion and loose metal material created by the action of the laser on a metal workpiece, a shielding gas jet is directed from a nozzle across the workpiece surface through the zone of action of the laser beam. The shielding gas rather than being allowed to go to waste is collected, purified of the metal material contained therein and fed back to the nozzle. This recirculation of the shielding gas is effected in ducting which incorporates in succession between the gas-collecting input end and the nozzle, a diffuser to slow the gas, a cooling chamber, a separator for removing metal particles condensed out of the stream, a pump, a filter and further cooling means.

Tubular composite arc welding electrode for vertical up welding of stainless steel

Abstract: In a tubular composite electrode for depositing stainless steel 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.

Water cooled welding gun

Abstract: A water cooled welding gun (10) includes an elongated current carrying inner tube (40) having a central opening (42) through which a consumable electrode and shielding gas may pass. The inner tube is provided with cooling passageways (50). A gas shielding nozzle (35) is connected to a gun tube cover (55) and is in thermal contact with the inner tube (40) through two layers of thermally conductive but electrically insulative materials (100, 105). The first layer (100) is preferably a rigid ceramic material, such as Al 2 O 3 , and the second layer (105) is preferably a thermally conducting but electrically insulating material, such as epoxy, which is pliable when initially applied. The second material (105) fills the gaps between the outer surface of the first material and the inside surface of the gun tube cover (55) to provide a direct thermal path for the heat transfer from the nozzle (35) through the cover tube (30) into the cooled inner tube (40) while maintaining electrical isolation therefrom.

Mig arc welding method

Abstract: This disclosure relates to MIG welding. In order to obtain an instantaneous short circuit type of metal transfer in the process using only a pure inert gas shield a small amount of rare earth elements is added to the weld wire. The amount of rare earth added is between 0.02%-0.03% by weight of the wire.

Method of doping shielding gas for use in welding

Abstract: A method of doping a shielding gas with a dopant which will react with oxone is characterized in that it comprises the steps of mixing the shielding gas and a carrier gas containing a known quantity of the dopant and having, with the dopant, a thermal conductivity differing substantially from that of the shielding gas measuring the thermal conductivity of the mixture and adjusting the composition of the mixture until the thermal conductivity reaches a predetermined value. In Europe the shielding gas will generally comprise argon and the carrier gas helium containing nitric oxide and/or halocarbon(s) as dopant.

Liquid cooling for a welding torch

Abstract: During operation of a welding torch (10), electrode wire (17) travels through a contact tip assembly (14) directly into a weld area. The torch (10) is exposed to elevated temperatures which can cause damage from weld spatter and increased deterioration of the assembly (14). In the welding torch (10), a liquid is delivered onto an expansion element (44) and gasifies owing primarily to the elevated welding temperatures at the expansion element (44). The result is to cool the assembly (14) and substantially overcome the problems of temperature. In a nozzle (18) equipped torch (10), the nozzle (18) directs a portion of the gasified liquid to the welding area for shielding the welding operation.

Apparatus and method for reducing the waste of welding gas

Abstract: An apparatus and method is described for reducing the amount of gas consumed during welding operations. A source of relatively high pressure inert gas is supplied to an individual welding station. At the station is a pressure regulator for substantially reducing the gas pressure and having an inlet in communication with the higher pressure gas supply and an outlet in communication with the inlet of a surge tank. The outlet of the surge tank is in communication with the welding apparatus. The volume of the surge tank is sufficient, and the apparatus functions, to supply a flow of gas, to the welding apparatus at the reduced pressure during transient when the welding apparatus is turned on, greater than that supplied during steady state conditions. In one embodiment, the apparatus of the invention includes a pressure gauge, pressure regulator, and surge tank within a sealed housing with the face of the pressure gauge positioned at one side thereof and visible externally of the housing. Access to the regulator for adjustment thereof is limited by means of a locked cover which, when opened, allows adjustment of the regulator through an opening with a suitable tool.

Welding or cutting method

Abstract: PURPOSE:To let deep penetration welding, cutting, gouging, etc be performed at high efficiency with the same device by flowing a specified amount of shielding gas from a hollow non-consumable electrode and digging down the melt zone CONSTITUTION:At the time of deep penetration welding of Al alloy, stainless steel, etc, helium gas or other is flowed as shielding gas 6 into a hollow electrode 3 to increase the arc potential of the central part of arc As a result, the quantity of heat input becomes relatively high and deep penetration welding is accomplished At the cutting or gouging, the rate of effluence of the shielding gas 6 from the hollow electrode 3 is increased to blow off the melt zone 9 by an arc flame 7 By changing the rate of effluence of the shielding gas 6 from the hollow electrode 3 in this way, the deep penetration welding, cutting and grouging are automatically accomplished

Process for the submerged-arc welding of light metals such as aluminum and aluminum alloys

Abstract: A welding process for joining aluminum materials in a horizontal welding position, without preheating, this process being highly economical and characterized by minimal environmental pollution, good strength and toughness of the welded joint, in which process the arc, as in submerged arc welding of steel plates, is covered by a flux layer and burns in a closed cavity, this process being realized by the use of a flux having a flux composition of 20-70% potassium chloride (KCl), 20-70% of an alkaline earth metal chloride, preferably calcium chloride and/or magnesium chloride (CaCl 2 and/or MgCl 2 ), 1-20% of calcium fluoride (CaF 2 ) and preferably 1-15% of a substance capable of lowering the melting point and/or releasing gas.

Composite wire for stainless steel welding

Abstract: A composite wire containing a flux for use in gas-shielded arc welding of stainless steels which contains, in the flux, the following inorganic components with respect to the total weight of the wire: 0.1 to 10% by weight of an anhydrous silicate, and 0.01 to 0.75% of a metallic oxide having a melting point of no more than 888° C.

Gelatinous coating for arc welding and method for underwater welding

Abstract: A gelatinous coating comprising particles of electrode coating and thermite suspended in a gel for use as an insulating coating and fluxing agent in underwater arc welding. Also, a method for underwater welding in which the gelatinous coating is scorched and the electric arc is initiated and sustained so as to weld the workpiece. Alternatively, a method for arc welding in flammable or explosive atmospheres.

Torch for gas-shield arc welding in deep narrow groove

Abstract: A torch for gas-shielded arc welding in a deep narrow groove comprises a current contact torch bit (1) with an electrode (2) and a nozzle for supplying the shielding gas to the welding zone, which communicates with a gas-feeding tube (4) and is provided with at least one row of horizontally arranged holes (5). The nozzle is a closed chamber (3) made as a symmetrical wedge whose sharp edge faces the electrode (2) and is in one plane with the axis thereof. The side walls and bottom of the chamber (3) feature at least one additional row of holes (6) whose axes lie in one plane approximately perpendicular to the walls (7) of the groove. The torch is designed primarily for welding of very thick workpieces.

Arc welding process.

Abstract: An arc welding process for welding a circumferential surface of a fixed pipe etc. by shielding a work part with a shield gas is provided. It is welded by a flat arc formed in a flat sectional view by simultaneously ejecting a gas from nozzles (19) to the arc formed between a welding torch (10) and a product for welding by placing a pair of the gas nozzle (19) for ejecting the gas at the end of the welding torch (10).

Surface hardening method of titanium and titanium alloy

Abstract: PURPOSE:To apply surface hardening of superior abrasion resistance by generating plasma arc while flowing a shielding gas to a Ti or Ti alloy blank material thereby subjecting the same to nitriding treatment then to diffusion treatment. CONSTITUTION:A gaseous nitrogen is flowed as a shielding gas by using a torch generating plasma arc, and mixed gases of nitrogen and argon or the like are flowed as working gases, thence electricity is conducted between an electrode 1 and a nozzle 2, whereby a plasma arc is generated. This arc is irradiated to the surface of a Ti or Ti alloy blank material, whereby it is nitrided. Thence, the shielding gas and the working gas are substituted with an inert gas such as argon, and the material is subjected to diffusion treatment. According to this method, the hardened layer is made deep and the surface TiN layer forms a wedge shape anchoring in the inside, whereby the firm surface hardened layer is obtained.

Builddup welding method

Abstract: PURPOSE:To stabilize opposite polarity arc and improve welding efficiency by forming oxide film on the surface of filler metal and supplying the same to molten pool. CONSTITUTION:In performing opposite polarity welding by a welding torch 1, filler metal 3 is fed into molten pool 5 at the specified speed by plural feed rollers, etc. At this time, the filler metal 3 is perheated by using a TIG welding torch 7 (an electric heater is equally well) and an oxide film 32 is formed on the surface of the filler metal 3 by the O2 and CO2 contained in the shield gas 8. If the balance of the forming speed at the cathode point of the filler metal 3 and the supply state of the oxide film 32 is maintained, the cathode point always stagnate near the molten drop 31 of the filler metal 3 and generates the arc 2, thereby enabling the formation of beads 6.

Welding at pressures greater than atmospheric pressure

Abstract: When metal inert gas (MIG) welding is carried out at normal atmospheric pressure, the electrode is made positive with respect to the workpiece because the use of a negative electrode gives little penetration. In undersea welding, as the pressure increases the arc stability and metal transfer in MIG welding become erratic and there is copious fume evolution. According to the present invention, MIG welding at pressures greater than 7 bars is carried out with the electrode negative with respect to the workpiece and with an electrode wire of diameter not greater than 1.4 mm; the slope of the power supply, as seen from the welding arc, is preferably between 6 and 15 V/100 A, which is higher than the 3 to 4 V/100 A used in positive-electrode MIG welding at normal atmospheric pressure.

Consumable electrode process arc welding method for steel

Abstract: PURPOSE:To improve the toughness of welded joint, by using a power source equipped with pulse generating device for restriking of arc, and welding at specified electrode projecting length and current density, in the consumable electrode process arc welding method of gas shielded system CONSTITUTION:A pulse generating device 8 is connected to the primary side of power source transformer for welding 7, and the welding current at the secondary side of the transformer is detected by a current trnasformer 9 Near zero position of this AC current, a pulse voltage is generated from the pulse generating device, and this voltage is applied between a base metal being welded 3 and a welding torch 4 through a resistor 10 This pulse voltage prevents the arc from extinguishing when the welding voltage becomes zero In this case, a wire 5 as the consumable electrode for welding should measure, in diameter d, 32-64mm, and the projecting length from the torch should be 4-15 times (mm) of d, and density of current being passed should be 40-150A/mm , and the current value should be 600- 2000A The shield gas to be used should be inert gas containing CO2<15%, and O2<5%

Consumable electrode type gas shielded arc welding method

Abstract: PURPOSE:To perform the welding in which sputter is hardly produced by using pulsating current for the welding current through the use of a pulse power supply and using the oxygen gas-carbonic acid gas mixed argon gas for shielding gas CONSTITUTION:A pulse power supply which generates pulsating current pulsating at a fixed frequency as welding current is used for a welding power supply The mixed gas composed primarly of inert gas (argon gas in particular) and comprising mixing carbonic acid gas at 5-20% and oxygen gas at 1-10% to this is used as the shielding gas The use of the pulse power supply for the welding current creates the state in which globule migration is easier to spray even when the welding current is low The entry of carbonic acid gas into the inert gas beforehand creates the state in which arc can be throttled and the mixed of some oxygen gas accelerates the oxidation action of the shielding gas and raises the temperature of globules These coupled with the pulsating current accelerate the spraying of globule migration

Producing device of composite wire material

Abstract: PURPOSE:To surely prevent the oxidation of the inside surfaces of composite wire material and improve corrosion resistance by providing shielding pipes in which protecting gas is filled between forming rolls so as to enclose the dissimilar metal tapes being formed in tubular form around a metal core. CONSTITUTION:The tape forming device 7 of the producing device for composite wire material consists of plural forming rolls such as upper and lower rolls 13a, 13b, 13c and side rolls 14a, 14b disposed along the moving path of a metal core 2 and dissimilar metal tapes 4. Shielding gas pipes 15a-15e of a small sectional area are provided by enclosing the metal tapes being formed between the abovementioned rolls and final roll 13c and welding device 8 with the ends of these pipes being converged. Reductive protection gas is filled in the abovementioned pipe by way of feed nozzles 16. In this way, the oxidation of the inside surface of the composite material tape is prevented with good efficiency by a small amount of gas and the decrease in the binding force between the core and tapes occuring in oxidation is prevented.

Vertical downward builddup welding method

Abstract: PURPOSE:To form high quality beads on the surface of a thin-walled pipe at high speeds by combining a small-diameter wire and shielding gas such as Ar or other and defining the speed of the welding wire and the input of welding heat. CONSTITUTION:Vertical downward build-up welding is accomplished by tilting a small-diameter wire of diameters 0.9 to 1.2 mm by 90 to 110 deg. in the welding direction with respect to the surface to be welded of a thin-walled pipe, using shielding gas of Ar or mixture of Ar and CO2 and combining conditions of welding current 120 to 200 A, welding voltage 18 to 24V and welding speed 30 to 70 cm/min. From these conditions, the input of welding heat of 3000 to 5000Joule/cm may be obtained and the beads of good shape are formed at high speeds.

Method and device of narrow groove welding

Abstract: PURPOSE:To make possible even welding by injecting arc-control gas toward the arc produced between filler core and base metals while controlling the same into pulse-form thereby moving and controlling the arc position. CONSTITUTION:This is the method and device of welding for narrow groove welding, particularly welding of a small groove gap. A torch body 10 is disposed coaxially to a contact tip 14 and a filler core 16 is disposed axially slidably to the contact tip in the state that it is electrically contacted therewith. Welding current flows between the filler core and base metals 18 to form an arc 20. Shielding gas 22 is led from between a shielding cover 12 and contact tip, whereby welding action is done. On the other hand, a gas flow passage 24 consists of a number of through-holes penetrated along the axial direction and is tilted toward the filler core. Hence, the arc shape is deformation-controlled by the arc control gas 26 which is injected from the gas flow passage.

Argon purity tester

Abstract: An inert gas purity tester having a housing made of transparent material and in which is located a thin wire tungsten filament. The filament is electrically connected to a variable electrical power source from, for example, an inert gas welding apparatus in order to provide a regulated flow of current to pass through the filament. The power source is then regulated until the filament glows white. The housing also has formed therein an inlet and outlet for allowing the flow of inert gas to pass therethrough. During the passage of gas through the housing, a trace of smoke detected at the white glowing filament indicates the presence of an impurity of oxygen within the inert gas such as argon. Viewing is continued until no more smoke is detected and it is therefore established that the impurity is no longer present in the gas. Thereafter, inert gas welding can be successfully undertaken.

Welding method of pipe

Abstract: PURPOSE:To shield with gas easily from the back side of welded part, by inserting two shield bodies from insert holes in the vicinity of welded joint, and expanding the bodies to shield the inside of the pipe, and filling with shielding gas, when welding stainless steel pipes or the like. CONSTITUTION:When welding two stainless steel pipes 1 at a joint part 2, the inside of the joint 2 is shielded with gas. In this case, fitting holes 7 are penetrated in the pipes 1 near the weld joint 2, and a metal fitting 9 having an insert hole 8 is welded and attached. Two expandable shield bobies 10 of balloon form are inserted from the insert hole 8, and disposed across the joint 2. Then, air or the like is sent into the shield bodies 10 to expand them to cause the circumference of the shield bodies 10 to pressure contact to the pipe inner wall to shield from outside. Shielding gas is supplied into this shield part from a pipe 12 to shield with gas, and welding is performed. When inspecting the interior face of the joint 2, a lever fitted with a mirror 13 is inserted from the insert hole 8, and the inside may be easily inspected by rotating the mirror 13 360 deg..

Gas shielded metal arc welding method

Abstract: PURPOSE:To prevent changing of cover and perform good welding by using the gas shielding cover of the specific size. CONSTITUTION:The width of the box part 2 of the gas shielding cover is made about the same as groove width so that even when the groove depth becomes shallow the gas shielding conditions similar to those of the case where the groove depth is deep may be obtained. The l1 size is set larger than the l2 size so that in the case of welding the weld line of the final layer the uppermoment step of the shielding gas injection part of a shielding nozzle 1, serving also as an electrode comes within the box part 2. As a result of this, the box part 2 provides the similar effect as the extension of the groove. Further, a skirt part 3 is installed to prevent dissipation of shielding gas owing to the fluctuations in the groove width. The above eliminate the need for changing the gas shielding cover depending upon the depth of the groove, resulting in unneeded interruption of work and improved working efficiency.

Flux-cored wire for vertical and horizontal position arc welding of stainless steel

Abstract: PURPOSE:To increase the viscosity of slag and molten metal and prevent the dripping of beads by mixing the metal powder contg. a specific amount of Ti in the flux of a flux-cored wire used for welding stainless steel in a horizontal vertical position. CONSTITUTION:The flux composition of the flux-cored wire used for welding stainless steel in a vertical or horizontal position by automatic or semiautomatic arc welding is made as follows: The flux is constituted of 20-45% the metal powder of Fe, Cr, Ni, etc. contg. 10-15% TiO2 or in total of one or more kinds of TiO2 and Fe2O, 0.5-4% in total of one or more kinds of LiCO3 and Na2CO3, 2-4% in total of one or more kinds of CaCO3, BaCO3 and MgCO3, 0.5-1.0% in total of one or more kinds of SiO2, Al2O3, and MgO, and 0.1-3% Ti. Ti acts as a deoxidizer, a denitrifier and an arc stabilizer, and increases the viscosity of the slag and metal melted by low-current arc welding, thereby enabling dripping of beads and undercut to be prevented.

Two electrode welding method of pipe

Abstract: PURPOSE:To improve working efficiency and the quality of weld zones by simultaneously performing the MIG welding of a flat position by a large capacity power source and the plasma welding of an overhead position by a small capacity power source in the circumferential welding of the pipe that can be rotated. CONSTITUTION:A pipe 7 rotates in the arrow direction 9 on revolving rolls 8, 8. Near the part right above this, the MIG welding of the short arc or the like of a large capacity power source involving the use of CO2 for shielding gas and making weaving welding in the direction 10 rectangular to the direction 9 is performed in a downward position by a consumable electrode 1. On the other hand, the plasma arc welding of a small capacity power source involving making upward weaving welding from the right side of the pipe in the same direction 11 as the direction 8 is performed by a tungsten non-consumable electrode 2. The electrodes 1, 2 which are set nearly at a right angle are so operated as to enable the harmony of the welding speeds of both may be taken.

Steel wire for gas shielded arc welding

Abstract: PURPOSE: To obtain weld metal of high quality free from time cracking by specifying the composition of a welding wire having specific diameters in the case of gas shielded arc welding of high current density. CONSTITUTION: The composition of the steel wire for welding contains 0.02%≤ C≤0.15%, 0.20%≤Si≤0.6%, 1.2%≤Mn≤2.4%, 0.04%≤Ti≤0.12%, 0.005%≤Al≤ 0.04%, and 0.0055%≤B≤0.0090%, and is restricted at ≤0.009% S, ≤0.15% Cu and ≤0.0045% N. In this case, high current gas shielded arc welding is carried out in an atmosphere contg. a shielding gas consisting essentially of Ar mixed with ≥15W≤50% gaseous CO 2 , with 1.0W2.0mm wire diameters d, within 500d≥ I≥(500d-150) range of welding current I(A). COPYRIGHT: (C)1982,JPO&Japio

Plasma arc builddup welding method by powder metals or other

Abstract: PURPOSE:To obtain homogeneous weld metal, eliminate loss of powder and improve workability by supplying metal powder or ceramics powder from a powder supply nozzle which has been formed to spiral groove form to the plasma arc center part. CONSTITUTION:Plasma gas 21 and shield gas 51 are supplied from cylinders not illustrated. Also, a pilot arc is generated at the end of an electrode 2 and the orifice portion of an electrode 30 by applying voltage from a power source 6 to the W electrode 2 and copper electrode 30. Next, a plasma arc is generated through the plasma gas between the base metal 1 to be welded and the electrode 2 by closing the circuit of a welding power source 7. Next, metal powder or/and ceramics powder is sent into this arc to let weld metal 11 to form on the surface of base meal 1. Here, a cooling water jacket 31 and spiral groove 32 are provided to the copper electrode body 30 to allow the foregoing powder to pass through the groove 32 and swirl, thereby concentrically supplying the powder toward the center of the plasma arc column and making the powder perfectly to the weld metal.