Method of arc welding
(57) Abstract:Usage: for arc welding of butt joints with narrow cutting edges. The inventive when welding in a narrow groove opening angle of the edges is performed in 25 - 30o. The welding process are the burner at an angle with an inclination relative to the vertical axis in 20-30oand the root of the weld is performed by decreasing the welding current and voltage of the welding mode subsequent layers of the seam. The width of the gap is 2-3 mm 5 table. The invention relates to welding, in particular, to a method of arc welding of butt joints with narrow cutting edges, and can be used in all sectors of the economy, which uses automatic or semi-automatic welding connections of any steel thickness up to 70 mm in the lower position using standard equipment.Known methods of welding in shielding gas consumable electrode in a narrow groove [1,2,3]
The disadvantages of the methods include: the need to use special equipment (expensive and scarce), lack of reliability of welding methods.The closest to predate less than 30o. Arc pressure on the molten metal is adjusted so that the width of the arc on the surface of the weld pool was smaller than the size of the gap in the junction, i.e., when performing a method for welding modes of the proposed method minimum value of gap width is 5.5 mm 
The disadvantage of this method is the increased size of the cross-sectional area of the weld, the complex process of reproduction method (regulation of arc pressure on the molten metal) and the use of special equipment for its implementation.The aim of the invention is to increase the productivity in the manufacture of welded steel constructions any brands up to 70 mm thickness by reducing the cross-sectional area of the weld and reduce the width of the gap; reducing consumption of welding materials, energy, improving weld quality by reducing the flatness (warp details).This objective is achieved in that before welding perform in any way the seam one-way sealing edges with a metal thickness of up to 35 mm and two-way when the metal thickness up to 70 mm, the width of the gap is 2 to 3 mm, the weld root perform at St. the seam and, welding torch have an angle with an inclination relative to the vertical axis 20 of the 30o. In addition, the proposed method of arc welding performed on standard equipment. The method is as follows.Collect details, prepared by the proposed method, stir in the cutting arc, perform root weld on the low modes. Then perform the filling of the cutting at the optimum welding conditions. To perform this welding method used standard equipment.Comparative analysis of the proposed solutions with the prototype shows that the claimed method of arc welding differs from the known reduction of the width of the gap, which is 2 to 3 mm, which allows to significantly reduce the cross-sectional area of the weld, therefore, to improve the performance of welding, to reduce the consumption of welding materials, electricity, and will simplify the welding process (no need to adjust the arc pressure on the molten metal), using standard equipment. Thus, the claimed method meets the criteria of the invention of "novelty."Analysis of the known welding methods showed that when following the main pairs of the arch, and the Assembly) will increase the quality of connections by reducing warping of parts. This allows to make a conclusion on the conformity of the proposed technical solution the criterion of "substantial differences".Example. Was welding arc welding in carbon dioxide product from sheet steel St 70 mm thick with bevel edges 25o(total angle) made mechanical gouging. Material consumable electrode welding wire رق-HTMT a diameter of 1.4 mm, the Parameters of welding conditions shown in table. 1.Welding performed from welding rectifier VS-300 semi-automatic And-547 on the hard external characteristic. The result is a high-quality suture (PL. 2), lack of penetration was no.The proposed solution allows you to:
1. To increase productivity in the manufacture of welded structures of large thickness by reducing the cross-sectional area of the weld (see tab. 3), reducing the complexity of cleaning the surface of articles from molten metal splashes.2. To reduce the consumption of welding materials, electricity up to 42% compared with the prototype while improving the quality of welded joints (increased strength properties, impact strength, reduced shrinkage).In table. 4 shows the optimal the economic impact by reducing consumption of welding materials, electricity, improving the quality of welded joints, the complexity of the preparation for welding, welding and strip from molten metal splashes.In the laboratory welding was tested welding method in the following modes (table. 5). Method of arc welding of butt joints in steel thickness up to 70 mm in the narrow groove with an included angle of less than 30owhere arc excite in section, and the welding process lead to the optimal mode, wherein, with the aim of improving productivity, reducing cost and improving quality, the gap width between the edges take is equal to 2
3 mm, welding lead angle of forward inclination relative to the vertical axis 20
30oat the root of the weld is performed by reducing the optimal values of current and voltage from 20 to 25%
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