339results about How to "Reduce welding stress" patented technology

A compound welding method by using semiconductor laser and CO2 laser comprises the steps: using a semiconductor laser and a CO2 laser to be positioned on one side of a welding line of welded metals in a certain angle, adjusting a focusing position of the CO2 laser to cause a light spot of the CO2 laser to be positioned in the light spot of the semiconductor laser so that the welding direction is consistent with the slow axis direction of the semiconductor laser; using the semiconductor laser to pre-heat the welded metals, heating the part to be welded entering into the light spot of the semiconductor laser to 200-400 DEG C, using the CO2 laser to weld, and performing a post-welding thermal treatment to the welded metals by using the semiconductor laser for the welded parts of the welded metals welded by the welding of the CO2 laser. Due to synchronous pre-heating and post-heating treatments to the welding process, the invention can effectively solve the problem of cold cracking in high-strength steel welding and improve the quality of high-strength steel laser welding.

The invention belongs to the field of the metallurgy technology and material science, and aims at providing a laser welding process method of brittle high silicon steel. Quick welding of strip tension rolling in the rolling preparation process of a high silicon steel thin strip is met. According to the mass ratio, an adopted alloy is prepared from 93%-96.5% of Fe and 3.5%-7% of Si; and the thickness ranges from 0.1 mm to 3.5 mm. According to the method, laser welding and a supplementary heat source are combined, and double-face or single-face welding is adopted; preheating carried out before welding is utilized for controlling the temperature rise speed, and heat preservation during welding and heat preservation carried out after welding are utilized for slow cooling to control the temperature reduction speed; and the temperature gradient and welding stress in the weld joint cooling process are reduced, and welding forming of the brittle high silicon steel is achieved. By means of the adoption of the method, cracks generated by the too high welding stress of the brittle high silicon steel can be avoided well, and the yield and the mechanical performance of the brittle high silicon steel are increased.

The invention discloses a friction stir welding process for combining back surface heating with frontal surface chilling. The friction stir welding process comprises the following steps: a workpiece to be welded is fixedly clamped; heaters are arranged on two sides of a welding line area; a chilling shielding gas protective cover for moving along with a stirring head is arranged on the outer side of the stirring head; the heaters are started to heat the back surface of the workpiece to be welded, so that the temperature of the upper surface of the workpiece to be welded is not higher than 250 DEG C; the chilling shielding gas protective cover is filled with the chilling shielding gas, and the covering range includes the welding line area and the upper surface area of the workpiece to be welded rightly above the heaters; friction stir welding equipment is started, and the rotating stirring head is controlled to insert in the workpiece to be welded; the shaft shoulder end surface of the stirring head is continuously pressed down by a section of distance, and the stirring head is stopped until a set inserting depth is reached; the stirring head is controlled to continuously rotate by a period of time under the set inserting depth, so that the welding line area of the workpiece to be welded is fully preheated to reach an excellent plastic state; and the stirring head is controlled to finish the welding work of the welding line area at a set welding speed.

The invention discloses a butt joint method for super-thick steel plates. The butt joint method for the super-thick steel plates comprises the steps of: machining grooves at butt joint parts of the steel plates, wherein the grooves are U-shaped grooves with symmetrical two surfaces, the angle of each groove is 8-10 degrees, and the radius of the arc at the root of each groove is 9-11mm; pre-heating before welding, wherein the preheating temperature is 40-60 DEG C, and locating welded joints after preheating; alternatively welding the welded joints on two sides by turning over for many times, backstep welding the layers of welding joints; keeping temperature in a welding process to be not more than 200 DEG C; keeping warm after welding, and cooling slowly. Since the U-shaped grooves are employed, the sectional area of the welded joints are greatly reduced, thermal input is reduced, control on welding deformation is facilitated, welding residual stress is reduced by backstep welding, two sides of the welded joint of the steel plate are subjected to uniform force by turning over for many times in welding, deformation in the welding process is corrected, the super-thick steel plate is rapid in heat dissipation after welding, quality of the welded joint is ensured by the method of keeping warm after welding, and stress deformation can be reduced by slowly cooling.

The invention relates to a pipe communication splice welding pressure-bearing type heat exchanger, which comprises tap water heat absorption pipes. Heat supply pipes are arranged in the tap water heat absorption pipes. The tap water heat absorption pipes are communicated through tap water communication pipes. The heat supply pipes are communicated through heat supply pipe communication pipes. The seal heads of the tap water heat absorption pipes are outwardly flanged and embedded in the ports of the tap water heat absorption pipes. The flanges of the seal heads of the tap water heat absorption pipes and the port edges of the tap water heat absorption pipes are in splice bilateral alignment edge-kneading welding connection. The walls of the tap water heat absorption pipes are punched and inwardly flanged. The tap water communication pipes are inserted in the punches of the tap water heat absorption pipes. The port edges of the tap water communication pipes and the punched inward flanges of the tap water heat absorption pipes are in splice bilateral alignment edge-kneading welding connection. Heat supply pipe blocking plates are embedded in the ports of the heat supply pipes. The heat supply pipe blocking plates are outwardly flanged. The outward flanges of the heat supply pipe blocking plates and the port edges of the tap water heat absorption pipes are in splice alignment edge-kneading welding connection. According to the pipe communication splice welding pressure-bearing type heat exchanger disclosed by the invention, two technical defects of higher water leakage ratio of the welding line and incapability of continuously producing hot water of the original patent product can be solved; and the heat exchanger has the advantages of no leakage and continuous hot water production.

The invention provides a method for improving a weld structure and performance of a magnesium alloy, which comprises the following steps: firstly, placing an magnesium alloy welding plate in a heat treatment furnace to carry out stress relief annealing for a certain time at a temperature of 250 DEG C to 350 DEG C; then, polishing and flattening a weld joint by adopting abrasive paper for metallograph to enable the magnesium alloy welding plate to be at the same height with a base material; and heating the magnesium alloy to a certain temperature higher than a recrystallization temperature and carrying out hot rolling after carrying out heat preservation for a certain time. The method is generally suitable for weld penetration magnesium alloy plates such as an AZ31 magnesium alloy plate, an AZ61 magnesium alloy plate, an AZ80 magnesium alloy plate and the like. Intensity of the weld joint and a heat affected zone of the welded magnesium alloy plate is obviously lower than that of the base material. By a means of carrying out hot rolling after carrying out heat preservation at a certain temperature, the method can effectively improve intensity of a magnesium alloy welding part and enables tissues and performance of the weld joint, the heat affected zone and a base metal to be consistent.

The invention relates to a horizontal luffing grab portal crane, including a four-bar linkage level luffing boom system, a travelling mechanism and a gantry structure. The crane is characterized in that: a luffing mechanism comprises a triple screw, a screw pedestal and an electric transmission mechanism. The outside of the triple screw is provided with a telescopic cover, the inside of the screw pedestal is equipped with a sleeve with nuts, and two ends outside the sleeve are provided with bearings in the screw pedestal. The electric transmission mechanism comprises a motor, a driving gear and a brake apparatus. The end of the triple screw is hinged to a boom, and the luffing mechanism is equipped with a speed adjustable control system. The four-bar linkage boom system and a gantry beam are both girder construction which employs a T-shaped structure and a rectangular pipe. The T-shaped structure is a main chord member, and the rectangular pipe as a web member is welded on a web member gusset plate. In the blanking process, the T-shaped structure and the web member gusset plate are integrated through numerical control cutting. The crane of the invention has high operating cycle frequency which can reach 6 million times, high luffing speed, smooth running of grab bucket, high operating efficiency and long service life.

The invention relates to a laser welding method for connecting molybdenum-group glass/kovar alloy by adding a Mo-Mn-Ni metal interlayer, and belongs to the technical field of connection of non-metal and metal materials. The method comprises the following steps: cleaning glass, removing a surface oxidation film from kovar alloy, and performing degreasing and deoiling treatment; preparing an oxidation film on the kovar alloy in an oxidizing furnace; preparing a Mo-Mn-Ni interlayer metal powder layer through a tabletting machine; arranging the glass at the bottom layer, the Mo-Mn-Ni interlayer metal powder at the middle layer and the kovar alloy at the top layer to form a sandwich welded structure, enabling the three to be in close contact, putting into a furnace, and preheating; radiating a laser beam onto the surface of the kovar alloy to perform laser welding; and after the welding is finished, quickly transferring the weldment into the heating furnace, performing stress-relief annealing, and cooling to room temperature in the furnace. The method provided by the invention promotes interface wetting, reduces postwelding stress, improves joint strength, lowers production cost and prolongs product service life.

The invention discloses a combined heat source welding method and device in vacuum/ in a protective atmosphere. The combined heat source welding method in vacuum/ in the protective atmosphere comprises the steps that in vacuum/ in the protective atmosphere, a heating furnace used as a basic heat source conducts overall heating on a welded piece to heat the welded piece to the high temperature of 600-1200 DEG C, and the temperature is kept; then, a welding gun used as a local heating heat source is used for heating and melting the area to be welded, and a weld joint is formed after cooling and solidification; the welded piece is cooled to the indoor temperature at a set cooling speed under the action of the basic heat source, and then the welding process is completed. The combined heat source welding device in vacuum/ in the protective atmosphere is composed of a vacuum pump group, the furnace, a heating chamber, a welding power source, a basic heating power source, a control cabinet, a high-temperature-resistant numerical control moving mechanism, the welding gun and a wire feeding mechanism. By the adoption of the combined heat source welding method in vacuum/ in the protective atmosphere, welding cracks of low-plasticity metal materials at the indoor temperature can be effectively avoided.

The invention discloses a method for welding Q420 steel for a power grid iron tower, which is used for welding Q420 steel plates with the thickness of 12mm or 16mm and is suitable for two joint forms of a butt joint and a full penetration weld T-shaped joint. The process comprises the following steps of: welding by adopting a mixed gas arc welding process of 80% Ar plus 20% CO2 semiautomatic solidwire; by adopting a multi-layer welding method, welding a first layer in a horizontal welding position and welding other layers in a downward welding position after the back chipping, wherein the butt joint uses asymmetric K-shaped grooves, and groove angles at both sides of the butt joint are 45-50 degrees and 58-62 degrees respectively, the width of truncated edge of the groove is 0-3mm ,and the welding interface-gap is 0-3mm. In the invention, the welding process is optimally designed by aiming at the peculiarity of the Q420 steel for the power grid iron tower. The whole process saves time, labor and energy, and various test parameters of the welding joints all exceed national standards, thereby providing the technical support for the power grid iron tower production and construction.

The invention provides a one-sided welding double-sided molding welding method which is suitable for welding a titanium steel composite pipe. The one-sided welding double-sided molding welding method aims at solving the problems that in existing titanium steel composite pipe welding, operation of the welding process is complicated, the accumulated heat input is large, it is necessary to prepare special welding consumables, and the welding efficiency is low. The one-sided welding double-sided molding welding method for the titanium steel composite pipe comprises the following steps that (1), a flat bottom groove with a blunt edge is machined at the pipe end of the titanium steel composite pipe to be welded; (2), a welding area is cleaned; (3), a titanium alloy layer of the titanium steel composite pipe is welded through a laser welding method; (4), acetone is used as a binder so that evenly-mixed transition layer metal powder can be made into paste, the groove bottom is evenly welded, pressing is conducted, and drying is conducted; and (5), transition layer metal is molten through laser energy, the transition layer is formed firstly, and then filling of the steel metal layer is conducted through electric arc welding. By the adoption of the method, one-sided welding double-sided molding welding of the titanium steel composite pipe is achieved, and the welding quality of the titanium steel composite pipe is improved.

The invention discloses a process method for assembling and welding a pile leg of an ocean platform. According to the method, the production speed is high, and the percent of pass of products is high. A pile leg assembly is composed of a rack and two semicircular pipes. Coming cargo examination should be carried out on the rack and the semicircular pipes carefully, and the rack and the semicircular pipes are installed through a tool. The rack is turned over through a turnover device. The assembled pile leg examined to be qualified is lifted to an electric heating furnace stage trolley, conveyed into a furnace and heated, wherein the temperature ranges from 150 DEG C to 200 DEG C. The temperature in a hearth should be kept even. The heated pile leg is placed on the ground. Two welding joints are in the horizontal state. Manual welding rods are used for backing welding. Welding is performed on the pile leg by four welding workers from the middle position. The two sides are simultaneously and symmetrically welded. After welding is finished, the pile leg is turned over and welded continuously. After the welding joints are backed for 1 to 2 layers, the pile leg is lifted to roller carriers on a submerged arc welding production line and then formally welded. The welded pile leg is conveyed into a thermal treatment furnace, the heating temperature ranges from 200 DEG C to 280 DEG C and maintained for 2 to 3 hours, and then the pile leg is delivered out of the thermal treatment furnace.

The invention discloses an automatic submerged arc welding method for a pearlitic heat-resistant steel composite board. The significant advantages are achieved by changing the welding method and the groove type and adjusting the welding sequence. The automatic submerged arc welding method has the significant advantages that by optimizing the groove type, the welding material filling quantity is reduced, and the welding efficiency is improved; a mechanical mode is adopted to conduct groove machining and welding seam back chipping, parent metal hardening caused by rapid heating and rapid cooling of thermal cutting or carbon arc air gouging is effectively avoided, and the rolling machining and welding quality of a barrel is improved; outer edge back chipping is conducted immediately after inner edge base layer welding is completed, welding stagnation and reheating in the middle can be effectively avoided, and the welding quality is guaranteed; transition layer welding is conducted immediately after base layer welding is completed, composited layer welding is conducted after crack detection is qualified, repeated preheating and transition layer welding which are conducted after nondestructive detection of previous base layer welding is completed and qualified can be effectively avoided, and the composited layer welding quality is improved.

The invention discloses a low-alloy steel pipe welding process, characterized by comprising a welding process including the following steps: confirming a groove, clearing two sides of the groove, group seaming, tack welding, back welding, clearing welding splatters, fill welding in layers, cosmetically welding, clearing weld roots, cosmetically welding, clearing welding splatters, auto-checking appearance for qualification, stamping numbers and clearing, nondestructively detecting and clearing, repairing, and nondestructively detecting and clearing; the low-alloy steel pipe welding process of the invention enables strict and reasonable control for parameters of various process stages, the flow is standardized, welding stress and deformation are decreased, and therefore mechanical properties of a welded pipe are improved.

The invention relates to an after-heating laser welding method for a jointed gear ring and a gear and belongs to the technical field of a vehicle transmission. The after-heating laser welding method comprises the following steps: respectively preprocessing a jointed bevel gear and the gear; performing after-heating processing pressing and electromagnetic preheating treatment for a welding area; and lastly, placing the gear on a turntable, rotating the turntable for 180 degrees, jacking the gear out of a platform by a vertical shaft under the turntable, clamping the gear from an inner hole, pressing downward under the action of a reverse thrust bearing, and performing spot welding, pre-welding and deep fusion welding in turn according to an initial position for welding. According to the after-heating laser welding method, the problem that a gear assembly is subjected to welding deformation and crack generation during an after-heating laser welding processing process of the jointed bevel gear and the gear is solved, and a set of after-heating laser welding technical parameters suitable for bath production is formed.

The invention relates to a crane main beam welding machine. The crane main beam welding machine comprises a fixed mount, a movable frame which is arranged on the fixed mount along horizontal direction in a guiding manner, the crane main beam welding machine further comprises a movable frame driving device which is in transmission connection with the movable frame and drives the movable frame to do reciprocating motion along the horizontal direction, and the movable frame is provided with a welding fun which is used for conducting welding construction on a position to be welded of a crane main beam. The invention provides a crane main beam welding machine which can lighten the labor intensity of workers in welding and manufacturing of the crane main beam.

The invention relates to a seam welding device for a locomotive capacitor square housing. The seam welding device comprises a welding platform, a rack, a suspension, a jacking plate, a positioning plate and a clamping plate. An elongated welding groove is arranged in the center of the welding platform. The rack is provided with an opening end for the capacitor housing entering and exiting. The suspension is arranged below the welding platform and parallel to the welding groove, and is located at the rack opening end in a suspended manner. The jacking plate is fixed at the upper end of the suspension through a jacking cylinder. The positioning plate is arranged on one side of the jacking plate and is fixed on the rack through a horizontal displacement adjusting device. The clamping plate is arranged on the other side of the jacking plate and is fixed on the rack through the jacking cylinder. The capacitor housing can be mounted and fixed conveniently, a center seam and the welding groove can be positioned accurately, the welding seam can be uniform and straight, welding slag can be discharged downwardly timely, welding stress is small, and welding quality is good.

The invention discloses a welding method of a super-thick steel casting. Process steps include S1, preparing a joint: an asymmetric X-type groove is adopted; S2, preheating: the front side and the reverse side are uniformly heated, the preheating temperature is set within the range of 150-160 DEG C, and the heating rate does not exceed 100 DEG C / h; S3, back welding: gas shielded welding backingis carried out on flux-cored welding wires for three layers, and fire warming is carried out to remove stress after each weld seam is welded; S4, reverse side air gouging: air gouging back chipping and carburized layer removal are carried out; S5, reverse side back welding: back welding is carried out by three layers after the temperature of the steel casting reaches a preheating temperature according to the method described in the step 2, and fire warming is performed on each weld seam to remove stress; S6, filling and cover surface welding: the front side and the reverse side are welded respectively by one welder simultaneously and symmetrically, and hammering is carried out layer by layer after each layer of weld beads of each weld seam is welded; and S7, 550 DEG C *2h heat treatment after stress removal is carried out immediately after the completion of welding. By means of the method, welding stress and welding deformation can be significantly reduced, and the probability of generating steel casting welding cracks is greatly reduced.

The invention is a diffusion welding multilayer structure diaphragm capsule, belonging to the field of diaphragm capsule manufacturing. By adopting the methods of diffusion welding, machining and shaping, the manufacturing of diaphragm capsule in the invention can be realized. The main procedures include thin wall blank preparation, surface cleaning, surface modified treatment, welding-stopping treatment, diffusion welding, machining, shaping and the like. Compared with the multilayer structure diaphragm capsule manufactured by other methods, the multilayer structure diaphragm capsule manufactured by the invention has the advantages of fine fatigue property (above 1 million times), strong pressurization performance, adjustable rigidity, high compression ratio (higher than 80%), capability of micromation of inner holes, high precision of geometric dimensions, strong destabilization resistance, precise and controllable weldingline profile, adjustable width of weldingline and the like. By using the invention, the diaphragm capsule in the shape of circle, square and other shapes can be manufactured, and can serve as a compensation element of displacement and angle in hydraulic, barometric, transferring pipeline installation, an elastic compensation element and a pore damping element as well as a measuring element for a manometer and an altimeter; besides, the diaphragm capsule can be also used as a heat transferring finned tube for air conditioning, refrigeration and other devices as well as a metal capsule of separating gas or liquid for an accumulator and a storage box. The invention can provide multilayer structure diaphragm capsule products with fine performance for related industries.