Showing papers on "Filler metal published in 1974"

Welding method for dissimilar metals

Abstract: A method for welding dissimilar metals, wherein a filler metal is deposited on one end of the aforesaid dissimilar metals to be jointed, said filler metal being of the same material as that of another of said dissimilar metals; the outer surface of the weld metal thus deposited is machined to provide a joint surface adapted for welding; and an electron beam welding is applied along the interface formed between said joint surface of said weld metal thus deposited and the joint surface of another of said dissimilar metals.

Apparatus for ultrasonic welding

Abstract: Apparatus for welding a metallic component to a non-metallic component which involves interposing an aluminum layer between metallic and non-metallic components, preheating the metallic component and the aluminum layer, preferably by induction heating, to a temperature of at least 250*C and then subjecting the components to ultrasonic welding.

Method of underwater welding

Abstract: The invention relates to a welding torch for welding underwater and to a method of underwater welding using the welding torch. A high speed stream of water is directed from a nozzle on the welding torch obliquely onto a member or members to be welded to form a flared-out curtain of water. Gas is injected into the volume enclosed by the curtain of water to create a gaseous atmosphere and welding is carried out in the gaseous atmosphere.

Electrode composition and welding method for arc welding steel

Abstract: A wire electrode for use in arc welding comprising a metal to be deposited on a substrate and further comprising a flux, said flux comprising:

Apparatus for welding a flange to a pipe

Abstract: Apparatus for regularly welding a tack welded flange to a pipe in which welding torches for welding outer corner on the pipe and inner corner of the flange are automatically positioned. To this end means for positioning the welding torch for welding the outer corner is provided and means for moving the welding torch for welding the inner corner according as the former welding torch is moved for positioning the latter welding torch.

Process for fusion-welding iron-nickle-cobalt alloy and copper or said alloy, copper and iron

Abstract: In a process for fusion-welding a binary combination of an iron alloy containing 50 % by weight or less of nickel and cobalt combined and copper; or a ternary combination of said iron alloy, copper, and iron, including the steps of bringing members of said binary combination or ternary combination into gapless contact with one another and subjecting the contact zone to a treatment including at least one of electron beam welding, laser beam welding, plasma welding, and TIG welding without use of a filler metal, an improvement which is characterized by supplying welding energy necessary to form in the welding zone molten weld metal having such a width and depth that have been determined from the composition and thickness of said base metals so that the composition of the weld metal may fall within the specified area in a diagram, shown in FIG. 1, representing composition of a three component system, said specified area being enclosed with straight lines connecting successively the point X (97 wt-% Cu, 2 wt-% Fe, 1 wt-% Ni + Co), the point Y (2 wt-% Cu, 49 wt-% Fe, 49 wt-% Ni + Co), the point Z (2 wt-% Cu, 97 wt-% Fe, 1 wt-% Ni + Co), and the point X except for the area enclosed with straight lines connecting successively the point a (35 wt-% Cu, 32.5 wt-% Fe, 32.5 wt-% Ni + Co), the point b (10 wt-% Cu, 45 wt-% Fe, 45 wt-% Ni + Co), the point c (8 wt-% Cu, 91 wt-% Fe, 1 wt-% Ni + Co), the point d (45 wt-% Cu, 54 wt-% Fe, 1 wt-% Ni + Co), and the point a. According to this improved process, development of weld cracking can be prevented.

Method of bonding sintered iron articles

Abstract: Sintered iron articles are bonded together by oxidizing a substantial portion of the iron forming the articles to Fe3O4, preparing the faying surfaces for bonding, interposing brazing filler metal between the faying surfaces, and then heating the parts to form a brazed bond therebetween. This invention relates to the field of bonding metal articles, and more particularly, to an improved method of bonding together sintered iron articles.

Arc welding rig for tubular articles - has excitation coils producing circular arc revolving in annular chamber filled with inert gas

Abstract: Annular workpieces (rings, tubes) are arc welded without any addition of filler metal or of electrodes by an arc which moves on a closed circular track inside a closed chamber. The two pieces of the chamber contain two excitation coils and have a seal ring at their sliding joint. Inert gas is introduced tangentially into the annular chamber.

Electron beam butt welding - using filler strap in and/or over butt joint gap

Abstract: To join two abutting metal plates by electron beam welding, a bar of a filler metal is laid over a gap at the butt joint. The electron beam is directed on top of this bar so that it melts and fills the gap. The gap is so dimensioned that the molten metal just fills it. The gap can be partly filled up by a filler metal insert or powder prior to welding. A copper backing plate can be used at the other side of the joint. This eliminates welding defects (unilateral fusion, arching) which are common in conventional electron beam welding. A simple electron gun is suitable for this method. The butt joint requires no careful preparation and can be flame cut.

Coating powder mixture

Abstract: An article is provided with improved resistance to hot corrosion through a coating on a metal surface based on an element selected from Fe, Co and Ni, the coating comprising a filled matrix bonded by interdiffusion with the substrate. The matrix is applied by impinging on the substrate metal surface a plurality of heated metallic particles, such as by plasma spraying. The coating includes a filler metal of aluminum and preferably an alloy of aluminum and at least one other element, for example Cr, deposited on and interdiffused with the matrix, such as through a halide vapor deposition process employing a mixture of aluminum powder and other powders. As a result of application of the filler metal, there is provided from the matrix a coating layer of an alloy including an average of about 8 - 20 weight percent aluminum, the application process resulting in substantial recrystallization of the matrix.

Flux-cored welding wire

Abstract: The flux-cored welding wire is intended to inert-gas shielded fusion welding of titanium and its alloys and includes a metal coating or tubular casting of titanium or its alloys and a powder flux core containing (per cent by weight): BaF2 -- 5 to 10, Fluoride of a rare-earth element -- 18 to 20, CaF2 -- 40 to 50, SrF2 -- the rest, the ratio of the weight content of the powder flux to the total weight content of titanium in the wire being from 0.3:1 to 1:1.

Welding Studies on Arc-Cast Molybdenum

Abstract: Although molybdenum has several metallurgical characteris­ tics that make its fabrication (espe­ cially by welding) difficult, it has some important properties that give it good potential for use in the next gen­ eration of nuclear reactors or in radio- isotope thermoelectric generators. To increase our understanding of the characteristics that have limited the use of molybdenum, a program was undertaken in support of the Molten Salt Breeder Reactor in which very complex prototype components for a chemical processing test stand were fabricated from arc-cast molybdenum by extrusion, machining, welding, and brazing. This paper presents some of the results of the welding development portion of that program. Procedures were developed for clean­ ing and stress-relieving this material before welding and for making helium-leak-tight welds by both the gas tungsten-arc and electron beam processes. A commercial orbiting-arc weld head was modified so that mo­ lybdenum tubing could be field joined

Technique for ensuring spot welds in a standard welding range

Abstract: Features which influence spot weld quality are included. The main welding parameters to achieve quality control are welding current, welding time and electrode force. Methods for achieving required spot diameters, typical welding ranges and use of destructive testing are described.

Studies on Prevention of End Cracking in One Side Automatic Welding (2nd Report)

Abstract: Recently one sided automatic welding has widely been prevailed in the assemble stage of Japanese shipyards. As one of the problems of welding procedure, as well as any other welding techniques, cracking which sometimes occurs near the end of weld, has become an important problem.The authors have proposed the calculation technique in the seam welding. The most significant feature of the method differing from the ordinary welding thermal stress analysis is that the conditions of calculation are simulated to be those of more realistic welding procedures.Then, the following assumptions are imposed in order to calculate stress and strain during welding.(1) Before welding, specimens are connected by tack welds and prepared edges are free boundaries.(2) Molten region containing arc tip is free from stress.(3) After the arc passed by, the plates are connected by solidifying of the molten pool, that is, free prepared edge changes to supported one as temperature is cooled down.(4) When the arc passed through a tack weld, it should be melted away and free from stress.In order to calculate the thermal stress analysis during welding, firstly we solved un-stationary heat conduction problems and obtained temperature distribution during welding. Based on the calculated temperature distribution, we analysed uncoupled thermal stress problems by using the finite element method, and conclusively showed that one of the main causes of end cracking is the transient tensile stresses generated near the end part of weldment when the stress re-distribution is taken place due to the melting of the last tack weld.To endorse the numerical calculation by the proposed method, experiments are carried out and it is confirmed that the method could be applicable to this kind of transient welding stress-strain state with time depending varying boundary conditions.

Seam welding large pipes - avoiding rupture as a result of differential stresses

Abstract: The edges of the initial sheet are joined together by tack welding or root-face welding, and subsequently filled by fusion welding. During and/or immediately after fusion welding at least sections of the pipe ends, particularly those outside the welding zone, are heated and heating is continued until the weld seam has cooled to exhibit the required strength.

Report on fundamental research on underwater welding

Abstract: The objective of the program was to conduct fundamental research on underwater welding and cutting. The study includes the following phases: Survey of fundamental information on underwater welding and cutting; A study of heat flow during underwater welding; Mechanisms of metal transfer in underwater arc welding; Effects of water environment on metallurgical structures and properties of welds; and Development of improved underwater welding methods.

Weld-brazing of titanium

Abstract: A joining process, designated weld-brazing, which combines resistance spotwelding and brazing has been developed at the NASA Langley Research Center. Resistance spot-welding is employed to position and align the parts and to establish a suitable faying surface gap for brazing; it contributes to the integrity of the joint. Brazing enhances the properties of the joint and reduces the stress concentrations normally associated with spotwelds. Ti-6Al-4V titanium alloy joints have been fabricated using 3003 aluminum braze both in a vacuum furnace and in a retort containing an inert gas environment.

Gas-metal reactions and porosity in the inert gas arc welding of copper

Abstract: A study has been made of the effects of welding and material variables on the occurrence of porosity in tungsten inert gas arc welding of copper. The experiments were based on a statistical design and variables included, welding current, welding speed, arc atmosphere composition, inert gas flow rate, weld preparation, and base material. The extent of weld metal porosity was assessed by density measurement and its morphology by X-ray radiography and metallography. In conjunction with this the copper-steam reaction has been investigated under conditions of controlled atmosphere arc melting. The welding experiments have shown that the extent of steam porosity is increased by increased water vapour content of the arc atmosphere, increased oxygen content of the base material and decreased welding speed. The arc melting experiments have shown that the steam reaction occurs in the body of the weld pool and proceeds to an apparent equi1ibrium state appropriate to to its temperature, the hydrogen and oxygen being supplied by the dissociation of water vapour in the arc atmosphere. It has been shown conclusively that nitrogen porosity can occur in the tungsten inert gas arc welding of copper and that this porosity can be eliminated by using filler wires containing small amounts of aluminum and titanium. Since it has been shown to be much more difficult to produce sound butt welds than melt runs it has been concluded that the porosity associated with joint fit up is due to nitrogen entrained into tho arc atmosphere. Clearly atmospheric entrainment would also, to a much lesser extent, involve water vapour. From a practical welding point of view it has thus been postulated that use of a filler wire containing small amounts of aluminum and/or titanium would eliminate both forms of porosity since these elements are both strongJy deoxidising and denitriding.

Underwater welding of low-carbon and high-strength (hy-80) steel

Abstract: This paper covers two subjects, the first being multipass welding of low-carbon steel, and the second, a feasibility study of underwater welding of HY-80, a quenched-and-tempered steel with a minimum yield strength of 80,000 psi. Shielded metal-arc process was used for welding these metals. An experimental study was made of properties of multipass underwater weldments of low-carbon steel. A study also was made into the feasibility of welding HY-80 steel underwater. Lap and tee joints were fabricated, and tests were conducted to determine joint strength, ductility, and overall weld quality.

Welding high-strength aluminum alloys

Abstract: Handbook has been published which integrates results of 19 research programs involving welding of high-strength aluminum alloys. Book introduces metallurgy and properties of aluminum alloys by discussing commercial alloys and heat treatments. Several current welding processes are reviewed such as gas tungsten-arc welding and gas metal-arc welding.