A method of submerged arc welding
(57) Abstract:The invention can be used in the welding industry. Perform submerged arc welding with non-consumable electrode. A filler wire serves in the tail part baths half the depth of penetration at an angle of 45-60oto the direction of welding. By eliminating unilateral cutting can improve the formation of the welded connection. 1 Il. The invention relates to mechanical engineering and can be used in the welding industry.There is a method of arc welding in shielding gases, which can improve the quality of forming a seam carry out forced pressure on the liquid metal in the rear part of the tub [MCI AC USSR N1240530 B 23 K 9/16, 1986].The disadvantages are the counterpart significant consumption of scarce protective gas, the leakage of liquid metal on the surface of the welded edges, unacceptably large for many materials the cooling rate of the weld metal.There is a method of welding with non-consumable electrode feed filler wire along the axis of the seam in the tail part of the bath welding in engineering /Handbook so 1/ Ed. by N. A. Olshansky): Machines which is across the width of the tank and to fill unilateral cutting requires a significant expense. Occurs strengthening seam, which in some cases you want to delete. In addition, due to the specific shape of the bath when welding submerged arc welding wire to be submitted at an angle of more than 70-80othat practically very difficult.The closest in technical essence and the achieved result is a method of submerged arc welding in which to eliminate cutting perform the second pass of the surface arc with reduced current and increased arc voltage [welding in Engineering /Handbook so 1/ Ed. by N. A. Olshansky - M.: Mashinostroenie, 1978, S. 221].The disadvantage are the counterpart of the decline in productivity with increasing labor and energy costs, the inadmissibility of repeated heating of a range of materials with low heat input (for example, the possibility of podelki welding area).When the submerged arc welding in one pass of the material of a thickness exceeding 5 mm due to the large currents in the molten metal have significant volumetric electromagnetic force towards the axis of the weld. As a result, the edges of the seam having undercuts. Reduction of scores is possible to achieve a significant reduction in welding speed, but in this case, those who and strictly along the axis of the weld. In real structures the current lead, as a rule, placed on one side of the seam, so that the current density from the electrical power supply and more. This leads to the violation of the symmetry of the cross-section of the seam and there is a one-sided undercut on the side opposite to the electrical power supply.The task to be solved by the invention is to improve the formation of a welded joint by eliminating one-sided cut.This object is achieved in that in the method of submerged arc welding with non-consumable electrode in contrast to the prototype in the tail part of the bath serves a filler wire half the depth of penetration at an angle of 45-60oto the direction of welding. Filler wire only fills the undercut without increasing the weld reinforcement. Thereby obtain economies of the filler material and the best form of the seam.The drawing shows a diagram of the way.A device that implements the method, is a burner - 1, the electrode 2. Position 3 - welded material. H - the depth of penetration. Wire - 4.A specific example of implementation of the method.Welding is carried out on samples of steel 12X18H10T Tolsa with the gradual penetration of the electrode to the amount of penetration of 10 mmWelding mode: welding current I=600 A, arc voltage Ud=12 V, welding speed VSt=10 m/hFiling filler wire is carried out in a time of transition arcs in svarivaemost product. Welding wire SV-08KH18N10T diameter dCR=0.3 mm, the feed speed of the filler wire VCR=1 m/min.While cooked sample Podrez is missing.When welding without filler wire in the sample occurs unilaterally cutting depth of 1.5 to 2.0 mmThus, the proposed method allows to eliminate one-sided undercut without re-melting of the weld. A method of submerged arc welding with non-consumable electrode, characterized in that the tail part of the bath serves a filler wire half the depth of the penetration angle of 45 - 60oto the direction of welding.
FIELD: restoration of parts cast of aluminum alloys with use of fusion welding.
SUBSTANCE: method comprises steps of cutting out flaw containing portion spaced equidistantly by distance (3 - 8)n from boundary of flaw; making insert of deformed aluminum alloy welded with casting alloy of restored part at relation of coefficients of percentage elongation Gd/Gc = 9 - 25, where Gd and Gc coefficients of percentage elongation respectively of deformed and casting aluminum alloys, n - thickness of cast part in restoration zone.
EFFECT: lowered labor consumption at restoring parts of aluminum alloys.
3 dwg, 1 tbl
FIELD: processes for making large-size thick-sheet orthotropic plates of carbon low-alloy steels in different branches of industry, particularly for bridge building.
SUBSTANCE: method comprises steps of relative orienting members of orthotropic plates; tack welding oriented members by means of non-consumable tungsten electrode in mixture of shield gases Ar (95 - 97)% + (3 - 5%) CO2 ; performing automatic continuous-seam welding and then trimming surface of welded seam. It allows simplify method for making welded large-size thick-sheet orthotropic plates of carbon low-alloy steels.
EFFECT: lowered labor consumption, shortened time cycle for making enhanced-quality plates, improved reliability of welded structures.
6 dwg, 1 ex
FIELD: electric arc welding of materials by means of non-melting electrode, namely methods for automatic argon-arc pulse welding of steel tubes.
SUBSTANCE: method comprises steps of preliminarily dressing tube butts and forming annular chamfers on inner surfaces of butts; abutting tubes; moving welded edges relative to electrode by step axial rotation of abutted tubes at revolution number 1 -1.5 rev/min; igniting arc 2 - 5 s before starting rotation of tube in order to heat welded seam zone; performing welding by means of torch inclined to tube axis by angle 60 - 85° relative to vertical line; sustaining electric current intensity in range 110 - 155 A for pulse duration 0.7 - 0.9 s; keeping electric current at pause period in range 10 - 30 A for pulse duration 0.5 - 0.7 s. Overlapping value of welded seam is in range 10 - 25 mm. It allows eliminate cracking of welded seam of tubes at bending samples by angle exceeding 160°.
EFFECT: enhanced quality of welded seam of tubes.
3 dwg, 1 tbl
FIELD: automatic welding increased-thickness joints of titanium alloys in inert gas by means of submerged tungsten electrode.
SUBSTANCE: method comprises steps of forming in welded edges cutout which is in the form of П-shaped dressing of edges at welding parts with slit gap; keeping relation of depth of dressing to its width less than 1; rounding acute angles of dressing; before welding introducing granulated additive material into slit gap and performing first pass at minimally admissible value of shape factor of fusion. In order to provide guaranteed fusion of walls, second and third passes are realized in the same mode. Electrode is placed in such a way that it is shifted relative to butt axis. At double-side welding passes are realized according to next order: first and second passes, then third, fourth and fifth passes.
EFFECT: enlarged manufacturing possibilities of method due to increased limit thickness of welded parts.
3 cl, 5 dwg
FIELD: machine engineering, possibly gas-shield electric arc welding by means of non-consumable electrode.
SUBSTANCE: method comprises steps of alternatively feeding several gases or their mixtures by pulses; at each next pulse feed using gases (gas mixtures) having ionization potentials different in comparison with those of gases or gas mixtures of previous pulse feed; periodically changing electric arc gap simultaneously with gas feed pulses; setting basic voltage of electric arc equal to optimal voltage in medium of gas or gas mixture with minimum ionization potential; setting difference between maximum and minimum voltage values of arc at periods of previous and next pulse feed of gases or gas mixtures in range 1 - 7 V.
EFFECT: enhanced quality of welded joints, possibility for adjusting fusion depth.
1 tbl, 1 ex
FIELD: gas-shield welding process with use of non-consumable electrode, namely torches for such welding.
SUBSTANCE: torch includes body of collet chuck holder. Said body has cylindrical surface near its working end and it is welded to electrically conducting gas conduit. Collet chuck is mounted in body for securing non-consumable electrode. Nozzle has cylindrical surface passing to cone surface and then again passing to cylindrical surface near its working end. Asbestos-cement insulator is arranged on surface of body of collet chuck holder; brass sleeve is put onto said insulator. Insulator is fixed to body by means of pressure ring-splitter having cylindrical surface passing to cone surface with radial openings.
EFFECT: possibility for making small-size torch for welding butts of metallic structures in hard-to-reach places of installation zone.
FIELD: plastic working of metals, namely processes for forming butt welded seams on tubes at making tube studs of U-shaped tube bundles using effect of localized hot plastic deforming of welded seam and near-seam zones.
SUBSTANCE: method comprises steps of preliminarily working tube ends by expanding them from cylinder to cylinder; assembling tubes with use of mandrel and placing intermediate member of additive material between joined end surfaces of end portions of tubes sized by expansion and end surfaces of step ring. Welded seams are formed by argon-arc welding due to melting material of intermediate member at its both sides adjacent to tube ends. The intermediate member is heated up and it is subjected to hot radial squeezing while concentrating its initial deformation in surface layers according to position of ring steps, welded seams and near-seam zones on mandrel for providing size of their outer diameter equal to initial outer diameter of tubes.
EFFECT: improved quality of welded seams.
FIELD: mechanical engineering; argon-arc welding.
SUBSTANCE: invention relates to methods of automatic argon-arc welding of austenitic steel pipes in manufacture of important constructions, such as high-pressure pipes used at nuclear power stations. Proposed method includes mechanical preparation of welding surface zone, veeing edges to miter of 3.0-3.5 mm and subsequent multiple-pass welding with nonconsumable negative electrode using filler wire. Welding edges are veed to miter of 2.7-3.0 mm. Welding at first pass is carried out with heat input of 0.35-0.55 MJ/m by impulse current. Welding at second pass is done with heat input of 0.6-0.86 MJ/m by impulse current at cross oscillations of electrode. Welding at third and subsequent passes is carried out with heat input of 0.62-1.16 MJ/m by steady current with cross oscillations of electrode.
EFFECT: increased capacity art welding and quality of weld joint owing to reduction of intercrystalline cracking of weld joint.
FIELD: mechanical engineering; welding.
SUBSTANCE: invention relates to design of torches for gas-shielded arc-welding by nonconsumable electrode. Proposed head of torch contains chuck with hole for electrode secured in body and gas fed channels, nozzle and partition arranged inside nozzle and formed by pack of gauzes. Gauze partition is made convex relative to welding arc flame. Head is furnished additionally with partition made of pack of gauzes arranged between chuck and gauze convex partition and made concave relative to flame of welding arc. Packs of gauzes are made of stainless steel of 3 to 5 layers. Gauze mesh is 0.3-0.5 mm.
EFFECT: provision of high quality of welding at relatively simple design.
5 cl, 2 dwg
FIELD: technological processes.
SUBSTANCE: invention concerns electric arc welding, particularly method of automatic argon arc welding of overlapping joints of steel pipes by non-melting electrode. The method involves preliminary pipe edge preparation and welding by tilted electrode with pipes rotating against electrode to form weld seam. Axial rotation speed of welded pipes is 0.1-0.8 rpm. Electrode is tilted in two planes: by 50-70 degrees against the article axis and by 60-85 degrees against weld seam plane.
EFFECT: improved quality of weld seams in overlapping joints of steel pipes, reduced hopping during rotation of long-length welded article, reduced cost of welded product.
3 cl, 3 dwg, 1 tbl