Method of welding longitudinal pipes welds

FIELD: technological processes.

SUBSTANCE: after joining the edges of pipe billet, the tack weld is made by arc welding. Main working weld is applied with the melting of the tack weld by laser or laser-arc welding. Then, inner and outer facing welds are performed by arc welding. Before the main working weld is made, the pipe billet is lifted to a fixed position by means of a drive mechanism connected to the control unit, on the input value of which the value of the angle of pipe billet inclination is entered. By means of driving support rollers, arranged to position and rotate the pipe billet by 360°, the joint of the edges of pipe billet is set to the position for 12 hours. Main working seam is made on the rise. Then pipe billets are lowered and either external face weld on the descent, without changing the position of joints of the edges of pipe billet, or inner face weld on the downhill is made, tentatively setting the joints of edges of pipe billet at 6 o'clock position.

EFFECT: increase of reliability of welded seam.

2 dwg

 



 

Same patents:

FIELD: process engineering.

SUBSTANCE: invention relates to welding of aluminium alloys. Invention can be used in ship building, aircraft engineering, and rocketry, etc. X-like profile of welding edges is formed to perform multipass welding with weld thickening. Every edge comprises central linear section connected by arc-like sections with inclined linear external sections. Arc-like section is curved to radius R=(0.30÷0.50)β, while central linear section is shaped to c=(0.05÷0.10)β, where β is welding edges depth.

EFFECT: higher static strength and fatigue strength of welds.

4 dwg, 3 tbl

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: aluminium steel joint is obtained by fusion welding of a transient two-layered aluminium steel-element with elements from the same materials by fillet welds. Welding is performed with incomplete penetration of each of the layers of the transient element. Legs of the welds adjacent to the transient two-layered element are at least 1.5 and not more than 2.0 of its thickness on the side of the aluminium layer and at least 1.0 and not more than 1.5 of its thickness on the side of the steel layer, and the weld leg adjacent to the aluminium element being welded is within 1.0 to 1.5 of the value of the weld leg adjacent to the aluminium layer of the transient element.

EFFECT: method allows excluding the formation of delaminations at the boundary of the layers of the aluminium-steel element and provides the achievement of fatigue strength and operating reliability of weld joints.

2 dwg, 1 ex, 2 tbl

FIELD: metallurgy.

SUBSTANCE: first, a shell with an outside end thickening of a cylindrical shape and a spherical bottom of a variable cross section is made of an O-bar of high-strength steel like SP-28 or VP-30 of a rolled plate. A reinforced throat is made from carbon steel 35. The thickness of a weld edge of the throat is chosen in the ratio of 2:1 to the thickness of the shell weld edge. The structure is assembled in a welding and assembly device with a removable pad so that the coincidence of axes and an annular manufacturing clearance at the butt, which is equal to 0.10…0.16 of the thickness of the shell weld edge, is provided. Gas-shielded welding is performed.

EFFECT: invention provides the quality of the weld joint from dissimilar steels and the uniform strength of the weld joint.

7 cl, 10 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to production of large-sized structures of molybdenum and its alloys, for example, at welding of shells of high-temperature gas-static muffle shields. Structure sheet edges are trimmed and formed. T-like copper insert is fitted between trimmed edges to the clearance there between to comply with leg depth. Trimmed edges are welded together by electron beam at incomplete penetration over the height. Welding is performed by repeated heating of non-penetrated trimmed edges with filling of said clearance with said copper insert.

EFFECT: decreased brittleness of the structure.

3 dwg, 2 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to welding of overlap joints and can be used in power production, motor production, ship and railway car building. Power supply is connected. Plasma-forming protective gas is fed. Arc is excited at top element to penetrate both elements. Note here that top element features higher density that that of lower element metal. Depths of top and bottom elements are related as 1:3. Note also that elements are assembled to overlap by at least tem depths of bottom element while welding time is set (2…4)δ seconds where δ is total depth of the elements, mm.

EFFECT: reliable weld.

FIELD: medicine.

SUBSTANCE: device for making stents comprises a core and a sleeve. The core has a rigid and substantially cylindrical outer surface. The sleeve surrounds the core and has a variable inner diameter. The sleeve has a rest inner diameter. The core has an outer diameter. The rest inner diameter is less than the outer diameter. That provides extending the sleeve when fitting the core, and substantially placing it back to the inner rest diameter after the core is removed. According to the second version of the device for making the stents, the sleeve has a variable rest diameter and a working diameter. The working diameter is less than the rest diameter. The sleeve surrounds the core and contacts thereto, when the sleeve obtains the rest diameter. An auxiliary unit for making the stents comprises the sleeve having the inner diameter and configured to extend from the rest diameter to the working diameter after applying the expansive force. The working diameter is more than the rest diameter, which the sleeve has at rest. The sleeve is configured to place back to the rest diameter after the expansive force is removed from there. A method for making the stent by means of the device for making the stents according to the first version providing contacting the sleeve to the core for fastening the sleeve on the core. That is followed by contacting the sleeve to a metal relief sheet. The above sheet is then wrapped about the device, and the sheet ends are welded up to form the stent.

EFFECT: invention provides the protection of the upper surface of the stent during the making process.

30 cl, 9 dwg

Arc welding method // 2530104

FIELD: machine building.

SUBSTANCE: welding method consists in two-sided simultaneous fusion of opposite sides of a joint. The parts being welded are installed in a horizontal plane. Grooving with bevels and noses of 8-12 mm is carried out. One welding electrode is installed at each side of the joint, the said electrodes are shifted in respect to each other in longitudinal direction. The distance between the electrodes is chosen as equal to 1.0-1.5 of the weld pool length of the front arc. Powers of the welding arcs are regulated separately at each electrode. The travel speeds of the welding electrodes and the arcs are equal. Welding in overhead position is carried out on the side of the edge nose by means of a non-consumable electrode which is set ahead in respect to the direction of the welding path. The speed and power of a welding arc are chosen so that to provide for 25-35% penetration from the nose of the bevelled welded edges. Flat-position welding is carried out on the side of the edge nose by a consumable electrode. The power of a welding arc at flat-position welding is chosen so that to provide for 85-75% penetration from the nose. The diameter of the consumable electrode is chosen so that to provide for maximal filling of grooving cross section.

EFFECT: reduction of expenditures on additional material at welding and improvement of welding efficiency.

7 dwg

FIELD: metallurgy.

SUBSTANCE: proposed method comprises making of backing of allowance of one of the parts. Said backing is removed at machining after butt welding at vertical position of the beam. Backing depth and width equal 0.25-0.35 and 0.10-0.15 of butt depth, accordingly. Mark 0.004-0.006 of butt depth is made on back of backing opposite the butt to evaluate visually the absence of bridging by smelting rate.

EFFECT: high-quality weld.

2 dwg

FIELD: metallurgy.

SUBSTANCE: this method comprises machining of edges to make the skews over pipe or sheet with 2-3 mm circular transition to plating layer and nose from plating layer in the form of rectangular ledge. Skew of edges over pipe or sheets to nose is broken at angles of 1-2 and 4-8 degrees. Nose from plating layer is 2.5-3.5 mm high and 3.4-4.7 mm long. In compliance with second version, method comprises machining of edges to produce skew with nose over pipe or sheet and bore with skew on plating layer side to depth larger than thickness of the latter. Skew of edges over pipe or sheet to nose features angle of 1-2 degrees. Nose is shaped to rectangular ledge and is 1.8-2.3 mm high and 3.2-5.2 mm long while bore features skew angle of 52-57 degrees.

EFFECT: lower material input, simplified design of welding set, higher quality of weld.

3 cl, 2 dwg

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 automatic welding of fixed circular butts in horizontal plane. Invention can be used for welding pipes of refractory material of the VNS-16-grade. Pipes are jointed. Made joint is fixed by squeezing along butt edges. Ply of activation flux AF-71 as the mix dissolved in ethanol is applied the surfaces of said edges. Tungsten electrode arc is fired and displaced along said edges. In preparation of the weld, 1 mm deep mark with the angle of edges opening making 45 degrees in made in the butt between pipes.

EFFECT: perfected process.

2 cl

FIELD: machine building.

SUBSTANCE: invention relates to devices for butt-to-butt connection of sections of a guide for suspended movable hoisting mechanisms and similar devices consisting of two halves. The sections are coupled with the help of bushes welded to their ends. At coupling the sections, their bushes are matched and a bolt is passed through them with a nut being screwed onto its protruding end. The end section of a weld joint, which connects the bush with the guide section wall, extends sidewards from the bush by the distance of 10…30 mm from it at the angle of 15°…45° to the longitudinal direction of the guide section. The weld joint shall be continuous at the transition into the end section extended sidewards, the said section shall be straight or bowed in the zone where the angle with the main section is formed.

EFFECT: weld joint provides for better strength of the connection and resistance to dynamic loads.

22 cl, 3 dwg

FIELD: metallurgy.

SUBSTANCE: metal plates are pressed by electrodes and conduct preliminary current pulse between them. For these plates welding electrodes with work part in form of cone with top angle from 100° to 140° are used. By means of the specified work part the electrode penetration to the metal plate surface and electric contact between electrodes and metal plates are ensured. After conduction of the preliminary current pulse the pressing force is increased and main current pulse is conducted.

EFFECT: invention ensures high quality welded joints by method of contact spot welding of metal plates with one-side non-conducting coating.

2 dwg, 1 tbl

FIELD: metallurgy.

SUBSTANCE: first, a shell with an outside end thickening of a cylindrical shape and a spherical bottom of a variable cross section is made of an O-bar of high-strength steel like SP-28 or VP-30 of a rolled plate. A reinforced throat is made from carbon steel 35. The thickness of a weld edge of the throat is chosen in the ratio of 2:1 to the thickness of the shell weld edge. The structure is assembled in a welding and assembly device with a removable pad so that the coincidence of axes and an annular manufacturing clearance at the butt, which is equal to 0.10…0.16 of the thickness of the shell weld edge, is provided. Gas-shielded welding is performed.

EFFECT: invention provides the quality of the weld joint from dissimilar steels and the uniform strength of the weld joint.

7 cl, 10 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: machine building.

SUBSTANCE: invention can be used in power plant engineering at manufacturing of corrugated walls of welded transformer bodies with extensive surfaces of active cooling. Reinforcement rods are laid on the corrugations on both sides of a wall and are fixed by holders. The edges are clamped and are held at welding by welding jaws. A filler wire is supplied to the gap between the rods and the corrugation parallel to the rod being welded. Supply of the filler wire is stopped, and the filler wire end between the rods and the corrugations is melt by an arc along with welding of the rods in the point of their contact with the corrugation. At the moment of filler wire melting, the end of the filler wire is torn away from the weld puddle by a reverse motion of a feeding unit. The corrugation edges are welded to form a common weld puddle. After welding is finished, the welding torches together with wire feeding unit are moved to the next corrugation or the wall is moved by a step to get the next corrugation in the welding position.

EFFECT: method provides for improved quality of welding monolithing seals with simultaneously increased output of corrugated wall production.

2 dwg

FIELD: metallurgy.

SUBSTANCE: shell segments with longitudinal corrugations and bent edges are formed. Segments are arranged on a base with lodgements for corrugations and pre-fixed on the base. After that, a stiff crimp-on frame is arranged on the base coaxially to it above the segments. Then, final fixation of segments and electron-beam welding of longitudinal joints of segments is performed in a vacuum chamber along bent edges with their further local heat treatment. Welding of joints and their heat treatment is performed first in one joint along the whole perimeter of the shell, and then, subsequently for the rest joints. Welding is performed in a pulse mode with certain parameters. Local heat treatment of a weld is performed by heating the weld with a scanned electron beam. After welding and heat treatment of all joints is completed, the finished shell is cooled, unfastened and removed from the base.

EFFECT: invention allows simplifying a manufacturing process of thin-wall shells, enlarging technological capabilities by obtaining corrugated conical shells and providing high accuracy of parameters of the obtained welded structure.

6 dwg

FIELD: metallurgy.

SUBSTANCE: method means simultaneous action on the external surface of the welded pipe samples of the laser beam and arc in shielded gases. Arc is generated by consumable electrode with creation if the common welding pool. Preliminary depth of embedding of the laser beam focal plane relatively to the external surface of the welded samples is set equal to (5±0.5 mm), and distance between axes of the laser beam and electrode is set equal to (3±0.5 mm). Fusion penetration is performed with beam power ≥10 kW. Inclination angle of the welding torch relatively to the laser beam is adjusted within range from 30° to 60° with change speed of the inclination angle of the welding torch relatively to the laser beam determined depending on welding speed and radius of the welded pipe samples. As the shielding medium the gas mixture containing active and inert gases is used.

EFFECT: quality improvement of the welded joint, welding efficiency and possibility of pipe samples welding with higher thickness.

FIELD: metallurgy.

SUBSTANCE: invention can be used at manufacture of vacuum arc-extinguishing chambers (VEC) for vacuum circuit breakers for the rated voltage of 110 kV and higher. Assembly of portions pre-soldered with the first solder metal and having one or more non-soldered seams between them is performed. The second solder metal is laid with lower fusion temperature than that of the first solder metal. Sealing of the VEC made in a vacuum furnace is performed. Gas is pumped out of the furnace volume with additional exposure at the temperature of not more than 100°C with duration that is sufficient for removal of gas from inner volume of the VEC being made through unsoldered seams. Heating is performed to the degassing temperature of VEC portions at the rate chosen from a condition providing the pressure inside VEC of not more than 10-2 Pa with exposure at the same temperature. Short-time heating and exposure is performed at fusion temperature of the second solder metal. After heating is completed, seams are sealed. The method involves non-stem pumping-out and sealing.

EFFECT: method provides for a possibility of group treatment of vacuum arc-extinguishing chambers of a large size and combination of assembly, pumping-out and sealing operations.

3 dwg

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

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