37results about How to "Eliminate residual tensile stress" patented technology

The invention discloses a laser welding method for metal sheets applied to an ultra low temperature environment. The method comprises the following steps of: integrally putting a metal sheet I and a metal sheet II in an inert gas environment, heating to the dynamic strain ageing temperatures of the metal sheet I and the metal sheet II, welding a filler wire in a seam zone by adopting fiber laser, putting the welded metal sheets in a liquid nitrogen environment, and emitting high-energy short pulse laser to carry out double-side laser impact on the metal sheets covered with an aluminum foil. The filler wire is welded for the metal sheets through laser at the dynamic strain ageing temperatures, so that the seam quality of a metal welding joint is greatly improved, and the seam zone is combined tightly with the metal sheets; and by laser impact strengthening treatment of the welding joint and the metal sheets in the same working environment at an ultra low temperature, ultra low temperature corrosion resistance and mechanical property of a metal welding member are remarkably improved.

The invention provides a method for forming micro-texture in a composite mode on the inner surface of a cylinder sleeve through laser. The method comprises the following steps: step (1), a femtosecond laser device is used for processing a needed microcosmic shape on the inner surface of the cylinder sleeve; and step (2), a nanosecond laser device is used for strengthening the area of the microcosmic shape processed in the step (1) through laser shock waves. Under the condition of dry friction, micro-concave surface texture can be used as a storage device for storing wear particles to reduce abrasive wear and furrows on the friction surface, and therefore the wear rate is lowered. The laser shock waves can eliminate residual tension after the micro-texture is formed on the inner surface of the cylinder sleeve, and therefore deep residual compressive stress is formed, grain refinement is enabled to be more uniform, the hardness, the abrasive resistance and the anti-fatigue performance of the cylinder sleeve are improved, and the service life of the cylinder sleeve is prolonged. The invention further provides a device for forming the micro-texture in the composite mode on the inner surface of the cylinder sleeve through the laser at the same time.

A method for preparing a composite brush plated deformation line diamond wire saw, comprising the following steps of: preparing materials, selecting diamond or surface metallized diamond and nonconductive free particles, ultrasonically washing, using distilled water to repeatedly wash and bake; taking a straight line metal wire with the diameter of 0.1-2 mm as a cathode and an electric brush plating pen as an anode, washing the metal wire, pre-brush plating the metal wire, and then washing with deionized water; electric brush plating an amorphous state plating layer, taking pre-brushed plated metal wire as a cathode and the electric brush plating pen as the anode, and electric brush plating the amorphous state plating layer to obtain the diamond wire saw; and deforming the diamond wire saw through a deformer, thermally processing to obtain a latter deformation line diamond wire saw. The preparation technology has a simple device, high production efficiency, and recycle use of plating solution; and the produced wire saw has few shortcoming, a good performance and a long service life.

The invention discloses a method for manufacturing a delivery steel pipe serving an acid environment. The steel pipe comprises the following chemical components of raw materials in percentage by weight: less than or equal to 0.1 percent of C, less than or equal to 1.6 percent of Mn, less than or equal to 0.02 percent of P, less than or equal to 0.002 percent of S, less than or equal to 0.15 percent of Nb, V and Ti, less than or equal to 0.22 percent of Pcm, more than or equal to 1.5 percent of Ca/S and the balance of Fe. High frequency induction welding is adopted in welding of the steel pipe; the welding quality is improved in the welding process by increasing the welding extrusion quantity, controlling the open angle of seams and increasing welding protective gas; and on-line quenching and on-line tempering are performed in heat treatment of the seams by adopting six intermediate frequency heat treatment machines. By selection of raw material components and metallographic structures, completeness of a welding mechanism and improvement of the heat treatment process, the steel pipe has hydrogen induced cracking resistance and sulfide stress corrosion resistance and has high strength and high pressure resistance, the cost can be reduced, and the use of the steel pipe under the acid serving condition can be met.

The invention relates to a micro rolling and ultrasonic-assisted laser cladding device, in particular to strengthening to the surface of a cladding layer. The device comprises a workbench, a fixed check block, a workpiece, a first mechanical arm, a synchronous powder feeder, a laser device, a micro roller, a rotating device, an amplitude-change pole, a second mechanical arm and an ultrasonic generator. During laser cladding, the micro rolling technology and the ultrasonic technology are used for assistance, and adverse effects left during pure laser scanning can be eliminated to the largest degree by means of the combination. By means of micro rolling, dendritic crystalline lenses generated during cooling of the cladding layer are ground through the micro roller, the crystal structure is refined, and air pores are effectively suppressed. By means of the ultrasonic technology, residual tension generated during temperature decrease of the cladding layer is eliminated, and cracks are effectively reduced. The micro rolling technology and the ultrasonic technology are applied to the laser cladding layer, and compactness, isotropy and other properties of the cladding layer are further improved.

The invention provides a method for manufacturing a pre-deformation line diamond line saw through powder metallurgy, comprising the following steps: basic line manufacturing: selecting metal wires, stranding at least two metal wires into a line, and deforming the stranded line by a deformer to obtain a pre-deformation base line; powder preparation: weighing metal powder, a binder and diamond by mass percent, and adding the mixture into a blender mixer to evenly mixing; line blank manufacturing: putting the base line and powder into a mould, and taking the pre-deformation base line as a center to prepare a line blank by using a forming technology; and line saw manufacturing: putting the line blank to a sintering furnace for sintering, and cooling with the furnace to obtain the line saw. The manufacturing method provided by the invention has the advantages of simple process, low cost and high production efficiency. The produced line saw has excellent performance, high strength, good flexibility, high hold to diamonds, stable cutting performance, good chip discharging performance and long service life, and is not easy to crack.

The invention discloses a destressing warhead-curve-shaped aluminum alloy thin-walled cylinder and a machining process of the destressing warhead-curve-shaped aluminum alloy thin-walled cylinder. The destressing warhead-curve-shaped aluminum alloy thin-walled cylinder and the machining process solve the problems that an existing thin-walled cylinder is not thorough in destressing and the welding strength of weld joints can be easily lowered due to machining. The destressing warhead-curve-shaped aluminum alloy thin-walled cylinder comprises a warhead-curve-shaped thin-walled cylinder body (2), a front flange (1) and a rear flange (7). A front annular weld joint (3) in the perpendicular direction is arranged between an annular groove (10) of an annular cylinder body (9) arranged on the side face of the rear end of the front flange (1) and the front end of the warhead-curve-shaped thin-walled cylinder body (2). A hole base hole (4) is formed in the cylinder wall of the warhead-curve-shaped thin-walled cylinder body (2), and an positioning annular step (11) is arranged on the outer side wall of a hole base (5). The invention discloses an effective method for removing welding stress of the thin-walled cylinder. By means of the destressing warhead-curve-shaped aluminum alloy thin-walled cylinder and the machining process, surface residual tension of the thin-walled cylinder is effectively eliminated, the material structural strength is improved, and the fatigue life is prolonged.

The invention discloses a method for obtaining high-adhesion nano coating and a device thereof. The method comprises the following steps: impacting nano powder at 80-150 degrees centigrade by laser induction to obtain a nano coating, then, carrying out impacting treatment on the coating by laser induction at ultralow temperature by dint of ultralow temperature constant-high-pressure block and extrusion technology; and the device comprises a laser induction impacting system, a deep cooling treatment system, an auxiliary control system, an adjustable working platform, a heating platform and the like. According to the invention, the ultralow temperature constant-high-pressure block and extrusion technology is used; at the ultralow temperature, a base body is contracted sharply; the base body is prevented from outwardly extruding the coating by laser induction impact force; thus, the coating and the base body are contracted at constant high pressure; finally, coating atoms are combined with base body atoms more compactly; in addition, occlusion effect and penetration effect happen so as to fundamentally solve a difficult problem of poor adhesion of the coating and the base body.

The invention provides a method for realizing stress corrosion resistance of a stainless steel welding connector impacted by nanosecond-pulse laser. According to the method, a welding seam is impacted by adopting laser along an S shape, and an outer region of the welding seam is impacted along a direction parallel to the welding seam, so that pull stress of the welding connector is eliminated. By reasonably selecting power density, phase change does not occur and residual pull stress can be eliminated, so that a condition that the stress corrosion resistance performance of the welding connector is reduced is avoided. According to the method provided by the invention, the surface of a workpiece is impacted through the nanosecond-pulse laser, and no obvious mechanical force is used; a machining speed is rapid and automation is easy to realize; a complicated mold surface can be impacted.

The invention discloses a laser peening weight-reducing method and device for the riveting-altered-to-welding structure of a metal thin-walled part. The method includes: clamping a welded part, and scanning a weld joint position to generate a laser processing path; performing laser peening on the surfaces on two sides of the weld joint according to the laser processing path. The laser peening weight-reducing method and device has the advantages that during the laser peening on the surfaces on two sides of the weld joint, shock waves induced by laser of certain power striking on the surface of the metal thin-walled part are used to perform the peening reinforcing on the surfaces of the weld joint, and accordingly the residual tension stress of the weld joint area is eliminated, the grains of the weld joint area are refined, dislocation density is increased, and weld joint strength is increased; the deformation of the welded part is partially corrected, the dimensional precision of the part is guaranteed; the weight of the metal thin-walled part in an aerospace device can be reduced, and the weld joint of the welded structure can be optimized to increase welding quality.

The invention provides a laser cladding process based on thermal aging treatment. The laser cladding process comprises the following steps of (1) pretreating a cladding part and a flat sample; (2) clamping the flat sample, and arranging a heating device below a chuck clamp; (3) arranging a temperature sensor near a to-be-cladded area of the flat sample for detecting the cladding temperature; (4) carrying out a single-pass laser cladding test on the flat sample, and recording the temperature range achieved by the cladding surface under corresponding cladding process parameters; (5) clamping the cladding part on the chuck clamp, enabling a temperature control system to control the heating temperature of the heating device according to the recorded temperature range, performing dynamic temperature control on the cladding part, and maintaining the overall temperature of the cladding part within the temperature interval achieved by laser cladding; (6) setting the corresponding laser cladding process parameters, and carrying out laser cladding on the surface of the cladding part; and (7) after the cladding is finished, controlling to stop heating by the temperature control system, and slowly cooling to room temperature. According to the process, the generation of cladding cracks can be reduced, and the cladding quality and effect can be improved.

The invention discloses a surface recombination energy machining method for a high-water-head impact type runner bucket. The surface recombination energy machining method comprises the following stepsthat 1) clamping is conducted; 2) mounting is conducted; 3) the machining reference of a runner is determined; 4) a written machining program is executed by using a Hauck energy actuator A, and the surface of the runner bucket is machined; 5) a written machining program is executed by using a Hauck energy actuator B, and the root of the runner bucket is machined; and (6) after surface recombination energy machining of one bucket is completed through the step 4) and the step 5), indexing is conducted through a numerical control rotary workbench of a machining center, and machining of other water buckets one by one is achieved through the same steps. According to the surface recombination energy machining method for the high-water-head impact type runner bucket, anti-fatigue manufacturing of the root of the bucket is achieved, the anti-fatigue degree of the root of the bucket is improved, generation of fatigue cracks is reduced, mirror finishing of the inner side space molded surface ofthe bucket is achieved, a nano layer is directly machined on the inner side space molded surface of the bucket, residual tensile stress of the root of the bucket and a water cutting blade is eliminated, height-controllable pressure stress is preset, and the service life of the impact type runner is prolonged.

A method and system for processing an engine block that includes a cylinder liner. The engine block having a first material with different coefficient of thermal expansion than a second material forming the cylinder liner. The method includes providing an insulating barrier to the cylinder liner, and quenching the engine block. The insulating barrier provides a lower cooling rate to the second material forming the cylinder liner than a cooling rate for the first material forming the engine block during the quenching.

The invention discloses a stepped ultrasonic impact needle device and the application thereof; an impact needle and a muzzle try to have rigid collision by changing the shape of the impact needle, so that the problem of the prior art that the speed of the impact needle is reduced caused by that quite great friction force is produced when the impact needle with a pin has collision with an impact needle base muzzle is solved. Meanwhile, the collision method of the impact needle and an extended head of the impact needle is changed, point contact replaces surface contact, so that the stress direction of a contact surface when in collision is consistent with the axial direction of the impact needle, the impact needle does not easily deviate, and the ultrasonic impact efficiency and stability can also be improved.

The invention discloses a method for repairing micro-contact fatigue damage of a tooth surface and a repairing device. The method comprises the following steps that a to-be-repaired gear is fixed on a motion platform through a clamp; geometrical morphology characteristics of a to-be-repaired area are measured by using a three-dimensional morphology instrument, collected information is input to a comprehensive control and monitoring system, and material and mechanical characteristics of the to-be-repaired gear are compared through a database to determine optimal laser shock repair process parameters; the optimal process parameters are imported into a pulse laser generator, the laser generator emits laser according to the optimal process parameter scheme, and laser beams are exported through a light path regulation and control system and a light path system; meanwhile, a water restraint layer system controls a water nozzle to form a water restraint layer on the tooth surface; and the laser acts on the to-be-repaired area on the tooth surface, so that the gear generates the required reinforced repair effect, and the purpose of repairing the tooth surface damage is achieved. The problems that in a traditional repairing mode, the process is complex, roughness is high, abrasion resistance is poor, and the gear can be repaired only after obvious defects or faults occur to the gear are solved.

The invention belongs to the technical field of stress relief, and particularly relates to a weld bead residual stress relief device and method.The weld bead residual stress relief device comprises a supporting column, the supporting column is connected to the upper surface of a base through threads, and the supporting column is used for supporting a to-be-treated welding part; the impact unit is mounted on the base, and the impact unit is in contact with a to-be-treated welding part; the impact unit is used for generating an impact effect on the to-be-treated welding part to complete weld bead stress elimination; the pressing unit is installed on the inner wall of the shell, and the pressing unit is used for limiting movement of the to-be-treated welding part; the device is simple in structure, residual stress in a plurality of welding beads on the same welding piece can be eliminated at the same time, and therefore the situation that the fatigue performance of the welding piece is reduced and the service life is shortened due to the residual stress of the welding beads is avoided.