Method of laser or laser-arc welding of pipes

FIELD: metallurgy.

SUBSTANCE: after laser or laser-arc welding of pipes, the welded area of pipes is cooled by laser radiation until they are completely melted. The cooling of welded seam is performed in the temperature interval Ms, where Ms is the starting temperature of martensite formation, and to a temperature not lower than Mf, where Mf is the temperature of the martensite formation completion. Then it is reheated to a temperature of Ms (+100…300)°C with further final cooling. In this case, cooling is carried out in the air, or by water, or by a water-air mixture. Reheating is performed by an induction method or laser.

EFFECT: improved micro-structure of the welded seam.

3 cl, 2 dwg

 



 

Same patents:

FIELD: process engineering.

SUBSTANCE: butt welding machine can be used for jointing the butts if strips (11, 12) by contact welding at appropriate plant. Two symmetric pairs of clamping jaws (22, 32, 31, 21) of the device for welding of one end of one strip (11) with second end of the other strip (12) are designed to retain and to position said ends of strips (11, 12) for connection by contact welding. Each of said jaws (22, 32, 31, 21) includes part (222, 212, 312, 322) to contact with one of said ends of strips (11). Every said jaw features the geometry and at least material which allow the decrease in eddy currents generated in said jaws due to electromagnetic induction at thermal processing of the weld. Said part of said jaw makes the kedge extending in direction of the strip end so that the gap between strip and induction head equals the depth of said ledge with due allowance for the gap there between.

EFFECT: continuous and compact weld, uniform cross-section, high quality of weld of thin strips.

15 cl, 6 dwg

FIELD: metallurgy.

SUBSTANCE: weld joint is heated by sending an electric current via a weld joint up to 10 kA as current leads are fixed at different sides relative to the weld seam on the process lap of a blade and a blisk. In the process of thermal treatment they measure the temperature of the weld joint surface and adjust it by the variation of the current value within 540-620°C. The maximum permissible heating temperature is set with the condition of saving the fine-grained structure of the weld joint. The minimum permissible temperature is set with the condition of removal of residual welding stresses in a weld joint. Thermal treatment is carried out with AC current with thyristor regulation of its value.

EFFECT: invention makes it possible to increase the efficiency of removal of residual stresses of joints due to the reduced distortion of the blisk profile, and also to increase the efficiency of thermal treatment due to direct heating of the entire cross section of the weld joint by electric current of a high value.

3 cl, 1 dwg

FIELD: transport.

SUBSTANCE: process comprises reheating of rail welding zone in area P located at distance C from weld centre Q. Note here that 0.2Lh≤C≤3Lh, where Lh is the length of heat affected zone (HAZ) in rail welding zone.

EFFECT: weld with fatigue strength suppressing fatigue failures in rail web in horizontal direction and at bending at rail root.

13 cl, 4 ex, 7 tbl, 31 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to welding of metal wires. Welding is performed with the help of laser source to make the weld, in fact, not extending beyond the wire radial cross-section. Prior to welding, at least one of wires to be welded together is subjected to annealing in hot gas flow and/or, in welding, produced weld point is subjected to annealing by hot gas flow.

EFFECT: high-quality weld without further machining.

20 cl, 5 dwg

FIELD: metallurgy.

SUBSTANCE: in order to increase the level of viscoplastic properties, provide operating reliability of metal in a weld joint zone of drill pipes with friction-welded locks, heat treatment of the weld joint zone is performed, which involves heating for austenisation to the temperature of Ac3+(70÷120)°C, cooling and tempering in the temperature range Ac1÷80°C, and as per the second version, heating for austenisation to the temperature of Ac3+(70÷120)°C, cooling, additional heating at intercritical interval of temperatures Ac1+(30÷80)°C, and tempering.

EFFECT: invention allows increasing level of impact operation so that stable values of at least 16 J are obtained and at least 42 J at increased test temperature of minus 20°C, and the invention allows increasing structural service life of weld joints of drill pipes.

2 cl, 1 tbl, 1 dwg, 2 ex

FIELD: machine building.

SUBSTANCE: method involves passing of sign alternating pulses of electric current through the joint and heat-affected zone. Current pulses are passed in the joint cooling zone where temperature of metal is lower than the Curie point temperature by 50-100 degrees Celsius. The current pulses are passed perpendicularly to the welded joint. Duration of the current pulses amounts to 1.5-2.5 seconds and intervals between the pulses - to 1-3 seconds.

EFFECT: invention allows for the reduction of energy consumption and labour time at removing residual welding stresses, mainly, of longitudinally electric welded pipes of big diameter.

2 dwg

FIELD: heating.

SUBSTANCE: invention relates to heat engineering, in particular to a device of out-of-furnace heat treatment of welded products, and can be used in different fields of industry for heat treatment of large-sized welded products in the field of welded seams without the use of furnace equipment and also for preheating the ends of the products prior to welding. The device comprises a housing made in the form of a cylindrical segment, replicating the shape of the surface of the heated part of the product, the segment of the perforated cylinder coaxially mounted in the housing with the ability to form the combustion chamber with the heating surface of product. In the end part of the combustion chamber of the device the distribution gas collector with pipe for supplying gas is mounted, which is attached to the gas supply valve. At the opposite end part of the combustion chamber the collecting receiver of the exhaust coolant is mounted which is attached to the pipe, the exhaust fan and the discharge valve. The housing is provided with a pipe for supplying air with the valve.

EFFECT: ensuring effective out-of-furnace local heating of the products prior to welding, as well as carrying out high-precision local out-of-furnace heat treatment (drawing, thermal recovery) after welding.

1 dwg

FIELD: metallurgy.

SUBSTANCE: rail is heated over the entire cross-section in weld zone to 850-900°C. Then, rail head is subjected to forced cooling by airflow in weld zone while rail web and foot are cooled in air. Note here that rail head in weld zone is cooled to martensitic transformation temperature Mn°C. Note also that at Mn-Troom°C rail head subjected to peening, shots diameter being equal to 0.8-1.5 mm.

EFFECT: higher hardness and corrosion resistance.

1 tbl, 1 dwg

FIELD: metallurgy.

SUBSTANCE: section of transition from weld to parent metal is heated by argon-arc processing at displacement of arc over weld surface after liner friction welding and removal of extruded flash. Specific heat flow rate and arc displacement rate are set in compliance with numerical simulation of temperature field in article by preset equation. Maximum temperature of weld heating is set such that fine-grain structure is preserved while minimum temperature is kept to remove residual welding strains. Heating depth is defined by blade and disc machining allowances. Argon-arc processing is made in turns on blade back.

EFFECT: efficient welding and machining.

3 cl, 2 dwg

FIELD: metallurgy.

SUBSTANCE: proposed method is realised in heating chamber shaped to a segment following the article heated part surface and confined by housing, gas feed and smoke bleed manifolds and article heated surface. Article surface fragment is heated in heating chamber by surface combustion of diffusion gas tongues displacing along heating surface and by system of air jets flowing thereat perpendicularly. Formed combustion products are evacuated via collection manifold by smoke sucker and removed from working zone.

EFFECT: efficient heating before welding, high-precision local out-of-furnace heat treatment after welding.

FIELD: process engineering.

SUBSTANCE: invention relates to production of steel sheet articles from different-depth steel sheet or strips. Billets are welded together along the butt to get the weld (7) composed by edges of steel sheet or strip workpiece. To rule out loss of quenched structure produced by heating to austenitising temperature, at least one edge of sheet or strip (8, 9) is coated before welding with thick fluid or solid powder or aerosol-like matter including at least one component increasing the strength of the weld (10).

EFFECT: higher weld strength.

28 cl, 2 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to machine for production of polar plates by laser cutting. This machine comprises bed, laser cutting assembly, cutting manipulator to drive laser cutting assembly, control system and at least one strip feeder. Strip feeder comprises manipulator for gripping, means for strip feeding to preset length and strip release means. Cutting and gripping manipulators are arranged at the bed. Means for strip feeding to preset length is arranged between gripping manipulator and strip release means. Control system is connected with cutting manipulator, gripping manipulator and means for strip feeding to preset length.

EFFECT: production of plates for lithium-ion storage batteries and super capacitors by laser technology, higher quality of plates.

10 cl, 5 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to laser plasma welding of metals and device to this end. Invention can be used for welding of such materials as steel and aluminium by combined laser plasma effects. Welding parts are preheated in the weld area by plasma flux. Laser beam is directed to but of welding parts. Produced weld is additionally heated by plasma flux. Plasma flux is shaped to circle while laser radiation is fed via geometrical centre of circular plasma flux to said butt. Device for laser plasma butt welding of metals comprises plasma flux and laser radiation sources. Plasma flux source comprises outer and inner ring electrodes to produce plasma flux located in one plane with their geometrical centres aligned at one point. Laser radiation source can feed laser radiation via said geometrical centre.

EFFECT: intensified welding, lower rate of weld cooling, higher strength of the weld.

2 cl, 1 dwg

FIELD: process engineering.

SUBSTANCE: invention relates for surface processing to get glossy and dull sections. In compliance with this process, surface pre-coated with first copper ply and second ply including bottom nickel ply and top chromium ply is subjected to selective removal of chromium ply on sections to be frosted. Selective removal is performed by laser displaced above the surface. Note here that laser exposure and power are adjusted to get various texture. Then, ply of noncorrosive metal containing zirconium and chromium is evaporated from vapour phase on said surface.

EFFECT: production of glossy and frosted surface sections.

5 cl

FIELD: physics, optics.

SUBSTANCE: invention relates to a laser beam focusing head for laser cutting, a method and an apparatus for laser cutting of a metal component. The focusing head comprises a collimating lens (13) and a focusing lens (14). The collimating lens (13) and the focusing lens (14) are made of ZnS and have peripheral thickness of at least 5 mm. A deflecting mirror (15) operating at an inclination angle (α) from 40° to 50° is placed between the collimating lens (13) and the focusing lens (14) on the path of the laser beam. The laser cutting apparatus comprises a solid-state laser device (SL) emitting a laser beam with wavelength of 1.06 mcm to 1.10 mcm and power of 0.1 kW to 25 kW, said focusing head and a conveying fibre (CF) connecting the solid-state laser device (SL) and the focusing head.

EFFECT: invention provides a stable focusing position of a laser beam during cutting.

13 cl, 5 dwg, 1 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to welding of at least two components 102, 104 of super alloys. In compliance with this process, mail weld 110 if made with the use of the first filler metal arranged between said components 102, 104 and weld surface 112 with the use of second filler metal made over the main weld. Spacer 506 is fitted between said components provided with optional flute 105 made along the surface 114 of weld 102, 104. Filler wire 504 is fed over preset surface 114 or inside said optional flute 105. Two lasers 700, 702 or laser 600 with connected beam splitter 604 produce first and second laser beams 508, 510. Said beams are directed at focus points 5122, 514 spaced apart through preset spacing (509), for example, 0.05-1.5 cm. First laser beam 508 is used for making of the main weld 110 with the help of fist filler metal between components 102, 104. Second laser beam 510 is used for making of the surface weld 112 with the use of second filler metal on the surface of the main weld 110.

EFFECT: perfected method.

9 cl, 8 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to production of pipes by laser welding. Laser welding comprises emitting of two laser beams along edges at open pipe upper surface. Said laser beams are transmitted via different optical fibre glass and have focused spots of diameters making over 0.3 mm. Said laser beams are emitted so that front laser beam and rear laser beam are inclined to welding direction. Note here that incidence angles are defined relative to direction perpendicular to open pipe top surface. Front laser beam falls on open pipe top surface in welding direction before rear laser beam while the letter falls on open pipe top surface in welding direction after front laser beam. Front laser beam incidence angle is set larger than that of rear laser beam. Gap between front laser beam centre and that of rear laser beam is set at open pipe rear surface equal to 1 mm and more.

EFFECT: higher quality of weld, higher yield.

17 cl, 4 dwg, 3 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: temporary beads 3 and 4 are made on thick 2 and thin 1 parts. The bead 3 height is by 3-4 times higher than thickness of part 1. Height of bead 4 is equal to height of bead 3. Bead 4 thickness is determined by equation S2=(1+Δ)·S1. Beads 3 and 4 contact surface is treated by ultrasound in ethyl alcohol. Parts 1 and 2 are secured in welding fixture. Butt joint gap and beads 3 and 4 shift at least 10% of part 1 thickness are ensured. Laser beam 5 is directed to butt joint of beads 3 and 4.

EFFECT: invention increases weld strength due to rational design of the temporary beads.

3 cl, 4 dwg

FIELD: metallurgy.

SUBSTANCE: device to manufacture items by layer-by-layer laser agglomeration of powders contains tanks for powder and powder surpluses, located between them module for item forming including table with drive of its vertical movement, device for powder supply to the table from powder tank, and powder discharge to power surpluses tank, optical laser system for agglomeration of the powder nozzles installed above the table for air or inert gas supply on the powder layer, and gas intake installed under the table with possibility of connection with vacuum system. The table is made gas permeable and is equipped with installed on its top surface of the refractory gas permeable plate intended for powder layer arrangement on its surface and agglomeration.

EFFECT: improved quality of obtained items.

1 dwg

FIELD: machine building.

SUBSTANCE: module comprises a guide belt, a movable orbital carriage mounted on the guide belt and able of travelling along it. The carriage includes a longitudinal movement drive and a moving device consisting of a carrying roller system and a gear wheel. A joint monitoring sensor, a welding wire reeling device and a handler are installed on the carriage. The handler consists of two mutually perpendicular linear guides with motors, which can move in respect to each other. The transverse linear guide is equipped by a laser welding head, a wire feeding unit, an arc welding torch, a video camera and a controller.

EFFECT: invention allows for the increase of productivity and efficiency of welding process for fixed ring pipe joints and for the improvement of welded joint quality.

3 cl, 3 dwg

FIELD: systems for cleaning rigid surfaces.

SUBSTANCE: in order to improve quality of cleaning, surface is irradiated by means of space-modulated beam of laser irradiation.

EFFECT: improved quality of cleaning surfaces.

1 cl, 2 dwg

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