Seam welding (B23K26/24)
B23K26/24 Seam welding(5)
FIELD: metallurgy.SUBSTANCE: before welding, the contacting surfaces of sheets to be joined are treated with laser cleaning. Then the sheets are tightly pressed. The welded seam is formed by periodic repetition of basic elements of V-, U-, Ω-shaped geometric form, in particular ellipses or circles, laser beam at constant speed at 90° relative to connection in two stages: heating of steel surface with defocused beam to temperature of 600°÷700° and melting of steel sheet with focused beam with protection of melt with gas mixture of argon and helium. For different ratios of thicknesses of sheets to be joined, the steel melt provides melting of aluminium sheet by 2/3÷7/8 of thickness.EFFECT: simplification of welding technology, possibility to perform selection of rational geometric shape of the welded seam, improvement of welded joint quality and reduction of production rejects.4 dwg, 3 ex, 3 tbl
FIELD: oil and gas industry.SUBSTANCE: method for connecting and disconnecting pipes for bituminous oil extraction involves lowering pipes into well with laser welding junction and lifting pipes with laser cutting per one turn around the junction. At that, the utilised pipes are made of low-carbon steel. The upper edge of pipes is equipped with annular limiters which enable such laser welding and cutting that laser welding and cutting beam is at the pipes joint when rotating around welded or cut pipes when applying to wellhead equipment. When lowering the first pipe to be connected into the well, the pipe is secured by wellhead equipment to prevent axial displacement and turning and the annular limiter prevents it against leaving well. The second pipe is joined end to end to the first pipe. After that, the joint area is covered with laser welding device focusing on the limiter of the first pipe, with the possibility of rotation at a rate that allows high quality and air-tight welding of pipes to be joined. When the laser welding device is rotated for the first time, the joint location is checked. When it is rotated for the second time, the pipes joint is welded by laser followed by welded seam quality control. The pipes are lowered and the second pipe is fixed due to its annular limiter in the wellhead equipment. The pipes welding process is repeated until all welded pipes are lowered in the well. When pipes are removed from the well, the pipe closest to the edge is removed, and the second one is fixed by wellhead equipment to prevent axial displacement and turning and the annular limiter prevents it against leaving well. After that, the joint area is covered with laser cutting device focusing on the limiter of the second pipe, with the possibility of rotation at a rate that enables high quality cutting of the pipes to be joined. The laser cuts the pipes, when the laser cutting device is rotating. The first pipe is sent to the pipe racks, and the second pipe is removed from the well. The next pipe is secured in the wellhead equipment. The pipe cutting process repeats until the required number of pipes is extracted from the well.EFFECT: increased reliability of the pipe string when injecting heat carrier.3 cl, 2 dwg
FIELD: metallurgy.SUBSTANCE: method includes stringer installing on the collar, performed on the covering at the place of the stringer location, and its weld tack, positioning and clamping of the stringer in the welding area by means of the head with the guide rollers, stringer welding with covering collar simultaneously by two beams, directed from two opposite sides of the stringer and moving along the weld joint of the stringer. Thus the stringer welding from one side is performed by the first beam, providing weld penetration to the depth equal to 0.8-0.9 of the stringer thickness, and from the other striger side the welding by the second beam is performed, providing weld penetration to the depth equal to 0.2-0.3 of the stringer thickness. The first beam is moved in front of the second beam at the distance greater than the length of the welding bath of the first beam.EFFECT: invention improves the quality of stringers welded joints with the increased thickness and stiffness.7 dwg
FIELD: technological processes.
SUBSTANCE: invention relates to a method of laser welding compounds tube-tube plate. Before welding are assembled compounds tube-tube plate with a gap is less than 0.2 mm. Focal plane of the laser beam relative to welded surface of tube plate at a distance -5…+5 mm. Welding is performed in two stages. At the first stage is shifted from the joint laser beam in the direction of tube plate and penetration. At the second stage the laser beam is directed on the joint and welding is carried out. In welding area is inert protective gas in amount of 10-15 l/min. Tube face ledge height relative to welded surface of tube plate is not more than 1 mm. Penetration may perform with laser beam power of ≥ 1 kW at welding rate of ≥ 25 mm/s.
EFFECT: high quality of weld joint.
3 cl, 1 tbl
FIELD: machine building.SUBSTANCE: method of fork lug (18) manufacturing for hoisting devices with, in principle, horizontal in the work position fork blade (5), and adjacent to it via fork bend, in principle, vertical fork back (20), that is equipped with connecting elements (2, 3) for transportation devices, at that fork lug contains several connected parts means that at least some parts are welded with each other. At that parts of the fork lugs are welded by means of the electronic beam welding and/or laser welding. Weld between the adjacent surfaces of the parts is made from both sides over surface to minimum depth 15 mm.EFFECT: increased lug strength.11 cl, 16 dwg
FIELD: process engineering.SUBSTANCE: invention relates to method of jointing two or more parts by cold butt joint and laser welding and can be used in machine building. Prior to laser welding, parts (1, 2) are locked relative to each other on at least one of superimposed flat sections (1a, 2a) by cold butt joint. Then said parts are welded together by laser. Laser welding seam (4) is arranged nearby locking area (3) formed by cold butt joint. Laser welding seams (4) are made by straight and parallel beams nearby said butt joint area (3). Said seams (4) are oriented along direction of maximum stress.EFFECT: gapless contact of parts, minimum warpage caused by welding.8 cl, 3 dwg