The method of welding metal strips overlap
(57) Abstract:The method can be used for consolidation of the rolls on the endless rolling mills in the steel and engineering industries. On facing each other, the ends of the bands perform evenly spaced depressions depth not exceeding the thickness of the strip and the ratio of the areas of the cross-section troughs and separated protrusions 1<S RR/Sinvoice2. Combine the tabs of the end of one strip with the depressions of the other end of the strip. Heat the weld metal volume to a temperature not higher than the temperature of phase transitions. By precipitation deform this volume simultaneously over the entire area of the welded connection to the width of one lane. Increases strength of a welded joint is not only due to the diffusion of education total grains, but at the expense of tensile shear ledges of the base metal of the strip ends. 3 Il. The invention relates to the welding of metal and can be used for consolidation of the rolls, making long belt traction tool on the endless rolling mills, etc.According to GOST 2601-84 known welding pressure, which is carried out at temperatures below Dania necessary plastic deformation of the connected parts.As disadvantages of this method it can be noted that for each material you need to know to set and adjust a combination of parameters such as the degree, speed and temperature of deformation and strength of a welded joint on the shift is determined by the contact area of the articulating surfaces and the nature of relationships formed at the boundary .There is a method of welding the ends of the strips overlap , the essence of which is that during the welding pressure by using drive, the inlet zone of the welding electric current to heat the metal, the seam is unrolled in the direction of the width of the strip to its thickness.The main and very important disadvantage of this method is that, according to , when the roll welding diffusion processes in the area of the connection do not have time to develop so much to change the structure of the connection zone due to insufficient duration of the interaction under pressure connected surfaces. When this happens only gripe surfaces and welded connection has low durability and can be used only as a transport.The closest analogue is the welding method SMU method, on the contact surfaces of the welded bands perform evenly spaced depressions, before welding combine the resulting projections of the end of one strip with the depressions of the other end of the strip. Then heat up the weld metal volume method for electrical resistivity and produce joint deformation of the ends of the strips.The present invention is to provide a method of welding metal strips overlap, providing ravnopravnosti welded joints and base metal bands.The problem is solved as follows.Side surfaces of the ends of the welded strips facing each other, in the direction of the width of the bands perform evenly spaced depressions with a depth not more than half the thickness of the strip with the ratio of the areas of the cross-section troughs and separated protrusions 1 < SRR/Sinvoice2. Then combine the tabs of the end of one strip with the depressions of the other end of the strip. The method of electrical resistance heat weld metal volume to a temperature not higher than the temperature of phase transformations and by precipitation deform this volume simultaneously over the entire area of the welded connection to the thickness of odnoy sizes and precipitated simultaneously combined volume of bands over the entire area of the welded connection, allows addition of diffusion with the formation of common beans to increase the strength of the welded joint due to the tensile shear ledges of the base metal bands.The choice of parameters of projections and depressions is defined by the following considerations.The depth of the depressions should be no more than half the thickness of the strip, on the basis of ensuring the total thickness of the solid metal compound is not less than the thickness of the strip. The shape of projections and depressions may be different and determined by technological reasons and tools for their implementation.The ratio of the areas of cross-sections of the depressions and protrusions must be larger than 1 in order to ensure that the combination of depressions and protrusions with guaranteed clearance. The condition of the ratio of these areas is less than 2 due to the fact that the joint upsetting of the ends of the bands in the welding process, it is a guarantee fill with metal side ledges, gaps and create a continuous contour of the welded connection.Heating the deformable volume to a temperature not higher than the temperature of phase transformations excludes changes in the structure and, consequently, the mechanical properties of the welded joint compared with the base metal bands.At f is shown in Fig. 2 - the same, with a triangular trapezoidal protrusions and depressions of Fig. 3 shows a weld joining the strip ends after heating and precipitation.The method is as follows.At the ends of the bands perform evenly spaced Dina depth not exceeding the thickness of the strip with the ratio of the areas of their cross-sections to areas of cross-sections separating them protrusions 1 < SRR/Sinvoice2. Then combine the tabs of the end of one strip with the depressions of the other end of the strip. After being welded to the volume of down current from the welding transformer and heat up the volume to a temperature not higher than the temperature of phase transformations metal bands. Further, by precipitation deform this volume simultaneously over the entire area of the welded connection to the width of one lane. Within the volume of the weld zone to form a continuous contour welding, as shown in Fig. 3. Thanks to the strength of the welded joint tensile provided not only by formed by diffusion of common beans in contour welding, but also due to the tensile shear ledges of the base metal of the strip ends.Example
For welding of the ends of the strips 4 mm thick steel of ZOGGS monm;
- the width of the protrusions 1.0 mm;
the number of protrusions is not less than 4;
- heating temperature of the weld zone is not higher than 760oC.The proposed method of welding metal strips overlap should be used in the metallurgical and engineering industries for the enlargement of the rolls, in the manufacture of long tape pulling tool, such as the traction unit of the downhole pump unit.Sources of information:
1. Karakozov E. C. welding of metals by pressure. M: Engineering. 1968, S. 147.2. Mechanical equipment cold rolling. Edited by CL. - Corr. An SSSR, Leningrad Chimica. M: Engineering. 1972, S. 379.3. FR 2598643 A, 20.11.87. The method of welding metal strips overlap when facing each other, the surfaces of the joined ends of the bands perform evenly spaced depressions in the direction of the width of the bands, combine educated projections of one strip with the depressions of the other strip, heat welded volume method for electrical resistivity and produce deformation of the connection zone, wherein the ratio of the areas of the cross-section troughs and separated protrusions are selected from the ratio above the temperature of the phase transitions of the welded metal, and the deformation produced by precipitation simultaneously over the entire area of the welded connection to the width of one lane.
FIELD: mechanical engineering.
SUBSTANCE: proposed method is intended for manufacturing fuel elements using resistance-butt welding primarily for their joining to zirconium alloy cans. Welding is effected at equipment electrical resistance not over 30-fold resistance of can section forming welded joint having or not point discontinuities in the form of separate spots or chain of such spots forming no continuous line and measuring maximum ten thicknesses of weld in cross-sectional area of welded joint under check disposed at distance equal to two or three thicknesses of can wall from butt-end of plug located inside fuel element, welded joint being checked by uniformity of external fin. Length of poor fin formation section does not exceed 10% of joint perimeter.
EFFECT: enhanced quality of welds and reliability of fuel element sealing.
FIELD: mechanical engineering; manufacture of devices for contact butt welding of pipes with plugs for sealing rod-type fuel elements of nuclear reactors.
SUBSTANCE: proposed method consists in stacking the current lead, stop-cooler made from set of metal plates at increased electric resistance and holder made from dielectric material. Stack thus made is subjected to machining and to aging by welding the specimens. Stop-cooler is electrically shunted by means of plate-type shunts located in holes made over perimeter of device. Plate-type shunts are rolled in cylinder and are fixed in holes by releasing deformable electric plugs fitted in these holes.
EFFECT: reduced labor consumption; enhanced operational stability; extended functional capabilities.
2 cl, 1 dwg
FIELD: machine engineering, namely methods for contact-butt welding of tube with plug for making fuel elements of nuclear power stations.
SUBSTANCE: method comprises steps of fixing tube at embedding tube end in opening of welding fitting having predetermined value of electric resistance; placing plug having portion welded in tube wall and outer portion in electrode for supplying welding current to outer portion of plug; compressing parts by applying welding effort; heating parts by means of welding electric current and welding them. Outer portion of plug has several parts; its part adjacent to portion welded into tube wall has diameter exceeding diameter of said part but less than diameter of opening of welding fitting. At welding process part of outer portion of plug adjacent to portion welded into tube wall is at least partially introduced into opening of welding fitting for forming annular gap between said part of outer portion and tube end. Said annular gap is filled with outer burrs. Part of outer portion of plug that is not adjacent to portion welded into tube wall has diameter exceeding diameter of opening of welding fitting.
EFFECT: improved characteristics of articles, enhanced versatility of method.
4 cl, 3 dwg, 1 ex
FIELD: nuclear engineering; fuel elements of nuclear reactors.
SUBSTANCE: proposed fuel element plug has section welded deep into can, its diameter being smaller than outer diameter of can but greater than its inner diameter; it also has end cap. The latter has surface for supplying welding current and applying force. End cap diameter is not smaller than that of fuel element can. Annular drilling is disposed between part to be welded in and surface for supplying welding current. End surface of annular drilling crosses surface of section being welded in. Diameter of annular drilling ranges between diametric dimensions of adjacent sections of plug.
EFFECT: reduced hydraulic resistance to coolant flow in reactor, facilitated manufacture, universal mechanical design.
1 cl, 3 dwg
FIELD: mechanical engineering; welding nuclear engineering.
SUBSTANCE: invention relates to resistance butt-welding of tubular jackets with plugs at sealing of rod-type elements of nuclear reactors. Device for forming of joints contains current supply and shaping parts in which hole is made form end of tubular jacket. Current supply and shaping parts are made integral in form of metal non-split plate or metal split plate divided into sectors along planes passing through hole for end of tubular jacket. Diameter of hole for end of tubular jacket in current supply part is either equal to or greater than diameter of hole in shaping part.
EFFECT: simplified design of device, improved reliability in operation and quality of welding.
3 cl, 4 dwg
FIELD: mechanical engineering; welding nuclear engineering.
SUBSTANCE: invention relates to methods of resistance butt welding for sealing of jackets of fuel elements of nuclear reactors and in process of manufacture of clusters of fuel elements. Method comes to compressing pipe and plug by welding force directed along axis of pipe and plug, heating them by electric current with subsequent welding-in with deepening of plug into pipe. Diameter of plug on section of formation of weld seam is greater than inner diameter of pipe, but is smaller than outer diameter of pipe. Welding current and force is applied to plug in different cross sections. Surface to apply welding current is arranged parallel to axis of plug and at angle of 90° to surface for application of welding force between said surface and part of plug welding into pipe.
EFFECT: provision of multipurposeness of method, improved quality of welding and service and technological characteristics of article.
FIELD: mechanical engineering; welding; nuclear engineering.
SUBSTANCE: invention relates to resistance butt-welding of tubular jackets of fuel elements with plugs. According to proposed method, end of pipe and end of plug are fixed in electrodes. Ends of pipe and plug whose outer diameter is greater than inner but smaller than outer diameter of pipe are compressed. Relative heating of pieces by welding current is carried out with subsequent driving plug into pipe. Welding is done mainly by heating of plug. Seating place is formed in process of displacement of plug between surface of its welded-in part and inner surface of pipe in direction of plug travel out of zone of thermal influence in pipe jacket. Larger part of fin formed at welding, and zone with maximum structural changes caused by thermal influence are brought outside. Zone with maximum structural changes is arranged out of zone of weld joint, and fin brought out is used to form smooth mating between outer surface of pipe and plug.
EFFECT: improved operating qualities of welded joints and their manufacturability.
1 ex, 2 dwg
FIELD: mechanical engineering; welding; nuclear engineering.
SUBSTANCE: invention relates to manufacture of fuel elements of nuclear power stations which are sealed by resistance butt-welding. Proposed method of welding of fuel element jacket with plug comes to placing end of jacket with depression into welding equipment with preset electric resistance value and welding-in of plug into jacket wall to depth not less than twice thickness of jacket wall, with control of parameters of welding rate. Welding is carried out at rates providing distribution between areas of inner, found under jacket and outer, metal-fin forced out of butt joint of section at ratio not exceeding 3. Ratio of areas of sections of inner metal-fin arranged at two sides in any diametral section of weld joint made along its axis does not exceed two.
EFFECT: improved operation reliability of fuel elements owing to quality forming of weld joints.
1 ex, 2 dwg
FIELD: processes and equipment for joining tubular parts in hazard zones, for example for welding tubes used in oil production and (or) well tubes in oil- or gas -producing platforms.
SUBSTANCE: method comprises steps of placing joined end portions of tube parts at mutual gap (possibly, several mm) inside chamber filled with shield gas; pumping to said chamber explosion-proof mixture of fluids containing nitrogen and hydrogen; heating ends of tube parts in said space at least by means of three electrodes forced to wall of each tube part and spaced one from other along circle near end of respective tube. Electrodes provide passing of HF- current practically in circumference direction through segment of tubular part between said electrodes. Uniformly heated ends of tubular parts are moved one towards other for forming forge welded joint between heated ends of tubular parts.
EFFECT: possibility of high-quality welding tube ends, possibly ends of irregular-shape tubes at minimum inclusions of oxidized metal.
20 cl, 10 dwg
FIELD: machine engineering, namely apparatuses for forming joint of tube and plug by resistance contact butt welding at sealing rod fuel elements of nuclear reactors.
SUBSTANCE: apparatus includes assembled to pack annular electric current supply lead and casing of dielectric material. In said casing annular cooler-stop having increased resistance to welding current is arranged. Said cooler-stop is in the form of set of metallic plates electrically connected one to other by means of shunts placed in openings of apparatus. Said shunts are cylindrical ones and they are fixed in openings by means of plugs in which threaded screwed-in members are mounted. Openings are cylindrical ones and plugs are made of elastic dielectric material. Development length of shut surface exceeds circle length of opening where shut is placed.
EFFECT: simplified design, enhanced operational reliability and enlarged manufacturing possibilities of apparatus.
2 cl, 1 dwg
FIELD: metal structural members for skin.
SUBSTANCE: proposed structural member has built-in profiled rigidity members. Profiled rigidity members (2) have bulge (4) of definite thickness (f) which reduces towards joint area (3) or connection to definite thickness (a) at this joint area or connection; ratio of thickness (f) of base of profiled rigidity member (2) to thickness (a) at joint area or connection is more than or is equal to 2.
EFFECT: enhanced efficiency; high resistance to spread of cracks; increased residual strength.
10 cl, 4 dwg
FIELD: machine engineering, possibly manufacture of shells of rollers and belt conveyers.
SUBSTANCE: method comprises step of twisting strip having V-shaped edges to tube, squeezing it and welding tube edges with us of friction heat of metallic disc rotated and moved along butt of shell edges. Disc has concave surface in zone of its contact with shell for providing close adjoining of disc and shell.
EFFECT: prevention of burr creation.
FIELD: processes for welding reinforcing constructional member with main pipeline under pressure.
SUBSTANCE: method comprises steps of making constructional member 2 of two parts; placing it onto cleaned portion of pipeline 1; mutually welding them by lengthwise seams without electric arc touching of pipeline wall; placing at both sides of constructional members technological rings 3 spaced from member by predetermined distance and having two halves joined by lengthwise seams; welding constructional member 2 with technological rings 3 at forming lap-butt joints after preliminarily dressing end surfaces for chamfering edges; placing constructional member 2 on cleaned portion of pipeline 1 at gap no more than 0.5 mm; forming cavity in inner surface of ends of welded constructional member 2 and technological rings 3 by inversely chamfering by depth 1.0 - 1.5 mm and angle 30 - 45°; at welding partially filling formed cavity with melt metal.
EFFECT: enhanced quality and reliability of welded joints of slit type constructional members and main pipeline.
1 tbl, 1 ex