41results about How to "Reduce weld defects" patented technology

The invention relates to a double side dual-arc welding method. It includes the following steps that the work-piece connection part waited for welding is made both sides welding groove; the both sides welding groove and its both sides surface is ground and cleaned out before the welding; the two independent electric arcs elicited by two welding guns of the two welding machines are conducted both sides dual-arc symmetry bottoming welding respectively at the both sides welding groove; after the bottoming welding, the two independent electric arcs are conducted both sides dual-arc filling welding respectively at the both sides welding groove. The invention avoids the carbon arc-air gouging back gouging process, simplifies the welding process, so that the automation welding can be realized. It avails to practice gas shielded welding, ensure the welding quality, reduce the welding deformation, and decrease joint stress. The method can apply to important metal structural parts welding.

The process of producing aluminum plate-fin heat exchanger includes the steps of blanking, washing, mounting, brazing, argon arc welding and pressure test. The present invention adopts numerically controlled lathe with high machining precision for blanking; ultrasonic washing for high washing efficiency and high washing quality; continuous high purity nitrogen protected brazing for high brazing quality; and argon arc welding with welding robot for high welding quality and high production efficiency.

A manufacturing method for ultra-long and ultra-thick circular plate is suitable for the steel circular plate which has a length more than 10 meters and has a thickness more than 100 millimeters. The method comprises the following steps: forging a plurality of segments of ultra-thick cylinders; carrying out mechanical processing to make the inner diameter, the wall thickness and the surface roughness accord with the requirements; and processing bevels at two ends. The invention is characterized in that the plurality of segments after procession are placed on a rolling jig bed 5; an interface part is fixed with a fixing plate; then the butt welding is performed after the bevels are added with ceramic gaskets 6; the long cylinder is prepared; the cutting is performed; and the ultra-long ultra-thick circular plate with the required dimension is manufactured. The invention has the advantageous of capability of manufacturing the ultra-long and ultra-thick circular plate with the length of more than 10 meters and the thickness of more than 100 millimeters, having high mechanical property of the manufactured plate, and having simple and convenient manufacturing method, easy operation and reduced manufacturing cost. The manufacturing method for ultra-long and ultra-thick circular plate can be widely used in the watercraft manufacturing industry and other mechanical chemical industry.

The invention discloses a laser welding fixture and method. The laser welding fixture comprises a supporting rod, a positioning plate, U-shaped rotation arms and pressure covers; the supporting rod isarranged in the vertical direction, and the top end of the supporting rod is provided with the positioning plate in the horizontal direction; the upper surface of the positioning plate is provided with a storage groove, and the two sides of the positioning plate are provided with the U-shaped rotation arms; the pressure covers are installed on the U-shaped rotation arms; and driving devices are installed on the lower portions of the U-shaped rotation arms and used for driving the U-shaped rotation arms to rotate and do vertical reciprocating motion. The laser welding method comprises the following steps that a laser welding head is started, the U-shaped rotation arms on the fixture are started to rotate at the same time, and thus, the U-shaped rotation arms of the fixture rotate while thewelding head does rotary welding so that welding of an annular welding zone can be achieved at a time through the welding head; and a pressure sensor on the fixture can measure the pressure value applied to the pressure covers. According to the laser welding device and method, the welding sealing performance is good, and the welding efficiency is high.

The invention relates to a vertical finned flat tube heat exchanger, which is composed of a flat tube (1) and a group of rectangular fins (2) through welding; the flat tube (1) is shaped as a runway which is arc at both ends and straight in the middle; and the fins (2) are distributed in parallel around the straight edge of the flat tube (1) and along the vertical direction of the heat exchanger. The manufacturing method comprises the following steps: (1), producing the flat tube (1) and the fins (2); (2), cleaning the surfaces of the flat tube (1) and the fins (2), and then coating the solder; (3), welding; (4), cleaning the brazing agent residues; (5), removing the oxides and oily substances on the weldment surface; and (6), producing a shell body, collecting and sealing the tube plate, and completing the overall assembly debugging. The invention improves the heat exchange efficiency, reduces the flue gas resistance, increases the cross-section flow area and does not easily get ash deposited and scaled, which is easy in maintenance; besides, the production efficiency is significantly improved and the corrosion resistance is good so as to reduce the costs.

The invention discloses aqueous cleaning low-temperature welding paste and a preparation method thereof. The welding paste comprises the following components in percentage by weight: 85 to 90 percent of soldering alloy powder, and 10 to 15 percent of scaling powder, wherein the soldering alloy powder consists of the following components in percentage by weight: 36 to 44 percent of Pb, 18 to 22 percent of Bi and the balance of Sn; and the scaling powder is formed by mixing 2 to 10 weight percent of active agent, 1 to 10 weight percent of pasting agent, 20 to 30 weight percent of wetting agent, 2 to 10 weight percent of thixotropic agent, and 50 to 70 weight percent of solvent and the total percentage of all components is 100 percent. The welding paste is suitable for various welding processes, is high in welding speed, does not damage components, does not contain halogen and does not have corrosiveness, and residues are few after welding.

The invention relates to a welding seam positioning device and a welding method using the welding seam positioning device. The welding seam positioning device comprises a ceramic liner, a high-strength flat plate and a suction mechanism; the ceramic liner is fixed at the bottoms of a first plate unit and a second plate unit; the high-strength flat plate is pressed at the tops of the first plate unit and the second plate unit, and the suction mechanism comprises a first magnetic suction cup, a second magnetic suction cup and a handle fixedly connected with the first magnetic suction cup and thesecond magnetic suction cup. The welding method comprises the steps that the high-strength flat plate is pressed at the tops of the first plate unit and the second plate unit, the first plate unit and the second plate unit are sucked and tightly attached to the bottom surface of the high-strength flat plate through the first magnetic suction cup and the second magnetic suction cup of the suctionmechanism, the ceramic liner is fixed at the bottoms of the first plate unit and the second plate unit, and then welding starts to be conducted. By means of the welding seam positioning device and thewelding method, welding seams are continuous, the welding defects are effectively reduced, the risk of damaging base materials of steel plates is avoided, and the automation degree is significantly increased.

The invention discloses cleaning-free lead-based high-temperature soldering paste and a preparation method thereof and belongs to the technical field of hybrid integrated circuits. The soldering paste is prepared from, by weight, 85%-90% of brazing filler metal alloy powder and 10%-15% of brazing flux. The brazing filler metal alloy powder is prepared from, by weight, 15.5%-16.5% of Sn, 7.0%-8.0% of Sb, 0.8-1.2% of Ag and the balance Pb. The brazing flux is prepared from, by weight, 5%-10% of activator, 5%-10% of paste forming agent, 20%-30% of wetting agent, 5%-10% of thixotropic agent and 40%-65% of solvent. The cleaning-free lead-based high-temperature soldering paste is prepared through the steps of brazing filler metal alloy smelting, brazing filler metal alloy powder preparation, brazing flux preparation and soldering paste preparation. The soldering paste is high in melting temperature, has good wettability for a metal coating, and is good in brazing manufacturability, long in working life and suitable for soft brazing of electronic device silver cladding, gold cladding and copper.

The invention relates to a welding process, in particular to an automatic submerged arc welding small groove welding process. The welding process comprises the following steps: a groove is cut on a welding piece, the angle of one side of the groove is 35 degrees, and the angle of other side of the groove is 45 degrees; the H pair group of the welding piece is performed, and the welding piece is fixed by the spot adhibiting method, and the spot adhibiting fixing welding seam is arranged on the 45-degree side of the groove; the welding piece is welded, the 35-degree side of the groove is firstly welded, when one-third of the 35-degree side of the groove is welded, the root part of the 45-degree side of the groove is cleaned, after the cleaning, the welding continues, through the repeatedly staggered welding, the weld pass is completely filled. Compared with the prior art, the welding process has the advantages of reducing the welding time, improving the welding speed of the workpiece, ensuring the scheduling requirements on a project, reducing the filler level of weld metal, saving one-third of welding materials, directly improving actual economic benefits and reducing the welding deformation; moreover, because the angle of the groove is reduced, the welding process also has the advantages of reducing the pre-heating width of the welding seam, lowering the defect of the welding seam and lowering the repair cost.

The invention discloses a device and a method for welding a bourdon tube for a pressure gauge, and belongs to the field of pressure gauge production. The device comprises a base, a gas feeding tube, a water ejection tube, a first groove and a second groove, wherein the first groove and the second groove are formed in the base; one end of the second groove is vertically connected with the first groove; the gas feeding tube is fixed on the base; one end of the gas feeding tube is arranged in the second groove; the water ejection tube is arranged on the base. By the adoption of the device, a gas can be supplied in welding, so that through holes are prevented from being blocked, and meanwhile due to arrangement of the water ejection tube, weld seams can be conveniently cooled down, and meanwhile due to addition of special substances in water in the welding method, the anticorrosion effect can be achieved, and the welding defects can be greatly reduced.

The invention belongs to the technical field of an aluminum alloy welding and relates to a welding technology of a fully-enclosed aluminum alloy anti-roll multifunctional cabinet externally arranged at a heavy truck. The fully-enclosed aluminum alloy anti-roll multifunctional cabinet comprises a bottom plate, a top plate, a rear plate and side plates; the top plate is fixedly arranged on the frontside of the bottom plate; the rear plate is fixedly arranged on the rear side of the bottom plate;, the side plates are fixedly arranged on the left side and right side of the bottom plate correspondingly; a cuboid is defined by the bottom plate, the top plate, the rear plate and the side plates; lifting lug plates are fixedly arranged at the four corners of the cuboid; a door plate is buckled onthe four corners of the cuboid; reinforcing ribs are arranged at the four corners of the door plate in a crossed manner; and a bottom section is fixedly arranged under the bottom plate. In the welding process, the top plate, the rear plate and the bottom plate are welded with the side plates correspondingly, the bottom section is welded with the bottom plate, the lifting lug plates are welded with side plates and the bottom section, and door plate is welded with the reinforcing ribs at four welding stages correspondingly, so that the problems that energy conservation and emission reduction are not facilitated and the corrosion resistance can not meet the requirement since an existing vehicle-mounted multifunctional cabinet and anti-roll beams, which are made of carbon steel and steel plate materials, are heavy are solved.

The invention provides a fast frequency variable polarity TIG welding power source and system based on a SiC module. The welding power source comprises a double-path parallel power main circuit, a control circuit and a man-machine interaction system. The double-path parallel power main circuit comprises a three-phase rectification filter circuit, a fast frequency pulse current main circuit and a variable polarity current main circuit; each of the fast frequency pulse current main circuit and the variable polarity current main circuit comprises a primary inverter circuit, a high-frequency transformer and an ultrafast recovery rectification smoothing circuit which are connected in sequence; the fast-frequency pulse current main circuit further comprises a filter inductor and a high-frequency switching circuit which are sequentially connected behind the ultra-fast recovery rectifying and smoothing circuit. The variable polarity current main circuit further comprises a coupling inductor and a secondary inverse current conversion circuit which are sequentially connected behind the ultrafast recovery rectification smoothing circuit. The welding power source can reduce the size, is high in dynamic response speed, low in switching loss, high in energy efficiency and stable and distortionless in output waveform, and can improve the welding quality.

The invention discloses a welding method for a low-temperature steel casting and a marine plate. The welding method comprises the steps that S10, materials are prepared, namely the low-temperature steel casting and the marine plate are provided; the low-temperature steel casting is firstly chamfered and then is subjected to thermal treatment; the marine plate is not chamfered; S20, preheating is performed before welding, and the welded plates are preheated to 100 DEG C; S30, welding is performed; and multi-layer weld beads are arranged; each layer starts from the marine plate and ends at the low-temperature steel casting until the whole weld beads are finished. The low-temperature steel casting is chamfered before thermal treatment, and through thermal treatment, stress at chamfers is eradicated, so that welding quality is improved; the low-temperature steel casting and the marine plate are preheated before welding, and thermal preservation is performed during welding, so that welding joint defects are decreased after welding through the special arrangement of the weld beads; low-temperature impact performance of the welding joints and heat-affected areas is effectively improved; welding quality is ensured; and the welding joints can withstand low-temperature impact test at 60 DEG C after welding.

The invention improves a narrow-gap adjustable device and a cosmetic welding adjustable device for improving the bearing capacity of butt joints, which belong to the field of a welding technique and can acquire high-quality butt joints with good bearing capacity. A fastener is used for axially pressing and fixedly mounting a group of annular sheets with different thicknesses and two wheel rim bodies on a shaft sleeve; and the two wheel rim bodies and the group of annular sheets with different thicknesses between the two wheel rim bodies are arranged coaxially, and the surface profile of the integration of the wheel rim bodies and the annular sheets is matched with the surface shape of the weld reinforcement of the butt joints. The narrow-gap adjustable device is convenient in operation, and has the advantages of high efficiency, high adaptability and the like; and the device with the adjustability can shape the butt joints which have different thicknesses and are made of different materials during welding. Under the sequential action of the narrow-gap adjustable device and the cosmetic welding adjustable device, butt joints with less weld defects, fine grains, low welding residual stress, desired shape and size, and high bearing capacity can be manufactured.

The invention discloses an energy-efficient plasma electric welding machine device with the magnetically stabilized arc, including a body box, a spray head main body and a gas mixing chamber. The gasmixing chamber is arranged at the bottom of the body box, a gas pressurizing pump is installed on one side of the gas mixing chamber through a mounting piece, an argon storage chamber is arranged at one end of the inner bottom of the body box, an air pump is installed at one side of the argon storage chamber through a mounting bracket, a hydrogen generator is connected with the inner top of the body box through a connecting frame and an output end of the hydrogen generator is connected with the air mixing chamber through a pipe, a feeding chamber is arranged on one side of the hydrogen generator, a motor is installed at the bottom of the feeding chamber through bolts, and an infrared heating pipe is installed at the top part of the feeding chamber through a connecting seat. As the arc reaches a magnetically stable state, a welding column is thin and long, the penetration force is strong, the weld speed is fast, the welding seam defects are few, and the welding quality is high.