967 results about "Thick wall" patented technology

The invention relates to the technical field of metal forge piece machining, in particular to an irregular metal forge piece heat treatment method and system.The irregular metal forge piece heat treatment method comprises the steps that firstly, temperature compensation partitions are divided according to geometrical characteristics, and stepped preheating is implemented to establish a uniform basic temperature field; then, the heat preservation time of each subarea is independently regulated and controlled in the austenitizing stage, and sufficient transformation of a thick-wall area structure and control over the grain size of a thin-wall area are both considered; in the quenching process, partition strength adjustment is carried out based on a preset cooling map, and cooling parameters are dynamically optimized through real-time feedback; and finally, according to the residual stress distribution, carrying out partition stepped tempering. The heating and cooling uniformity is remarkably improved through partition dynamic temperature management, and the structure difference and thermal stress concentration caused by section sudden change are effectively inhibited; the microstructure is ensured to be uniform and stable through austenitizing control; the hardenability and the deformation resistance are balanced through a differential cooling strategy; and directional reduction of residual stress is achieved through an intelligent tempering mechanism, and the cracking risk is greatly reduced while the comprehensive mechanical property is improved.

The invention discloses a pulsed eddy current detection method and system for a thermal power pipeline with a coating layer, and relates to the technical field of pulsed eddy current nondestructive detection.The pulsed eddy current detection method comprises the steps that pulsed eddy current detection simulation and experiment are conducted under the condition of a three-dimensional simulation model and a test piece, and excitation current waveform, amplitude and frequency parameters are determined; an induced voltage signal is collected, peak values, time points and attenuation characteristics are extracted, the corresponding relation between the wall thickness, the coating layer thickness and the welding seam structure and detection signals is constructed, a parameterized database is constructed, and temperature correction is completed; and optimizing a sensor structure and a signal acquisition scheme according to a parameterized database, obtaining detection data in a pipeline operation state, completing two-dimensional imaging of wall thickness distribution and welding seam positioning, and forming detection information covering a straight pipe, an elbow and a welding seam area. According to the method, wall thickness detection and welding seam positioning of the thermal power pipeline under the conditions of a thick wall and a thick coating layer are achieved through the full-process design of test piece modeling, simulation experiment and imaging collection.

The invention belongs to the technical field of nondestructive testing, and discloses a vector coherence factor-based thick-wall austenitic stainless steel welding seam full-focus imaging method, which comprises the following steps of: acquiring full-matrix data through a TRL area array probe, constructing an imaging area, calculating a spatial relationship, optimizing a propagation path in combination with a Fermat principle, and obtaining a full-focus imaging result; the method comprises the following steps of: firstly, extracting an instantaneous phase of an ultrasonic signal to construct a vector coherence factor, reconstructing an imaging data matrix according to the coherence factor, and obtaining a phase coherence weighted full-focusing imaging result, so as to ensure that each pixel point can obtain an optimal propagation path, thereby generating a full-focusing image data matrix by adopting a point-by-point delay superposition technology; the method can effectively improve the signal-to-noise ratio and positioning and quantification precision of the thick-wall austenitic stainless steel weld joint detection image, and has good engineering application value.

An expandable introducer includes a hub having a distal end and a proximal end, and a sheath coupled to the hub and extending distally therefrom, the sheath defining a central lumen. The sheath is configured to radially expand from a radially unexpanded, folded state having a first diameter and to a radially expanded, unfolded state having a second diameter larger than the first diameter in response to a device passing through the central lumen. A wall of the sheath includes a thick wall region having a first wall thickness and a thin wall region having a second wall thickness smaller than the first wall thickness, wherein the thick wall region includes a coil embedded within the wall of the sheath.

The invention belongs to the field of production control, and particularly discloses a control method of a thick-wall optical product precision injection molding hot runner system, which comprises the following steps of: acquiring mold geometric data of local thickness distribution in a mold-containing cavity along a melt flowing direction, calculating theoretical cooling time constants of each region by combining material thermophysical parameters, and calculating the cooling time constant of each region; establishing a thickness-cooling rate mapping relation model; predicting the time when the melt reaches each area and the effective cooling time according to an injection time sequence; solving a temperature compensation value of a heating area corresponding to the hot runner by taking the minimum final temperature variance when the key area is ejected as a target; and finally, dynamically applying a compensation value according to a time sequence before the melt arrives, and withdrawing / adjusting after region filling is completed or a pressure maintaining stage is entered. The invention can balance the temperature field of the mold cavity, reduce the refractive index gradient and shrinkage defect, improve the optical performance and yield of the product, and is suitable for precise injection molding of the thick-wall optical product.

The invention discloses narrow-gap swing laser-MIG composite filler wire welding equipment and method for a thick-wall component, belongs to the field of thick-wall component welding, and aims to solve the problems that the side wall of a narrow-gap groove of a thick plate of 50-250 mm is not fused and the welding efficiency is low. The swinging narrow-gap MIG welding gun and the auxiliary wire feeding pipe are arranged on the two sides of the laser, dynamic cooperation of the main / auxiliary double wire feeding systems is adopted, the dynamic characteristics of a molten pool are improved in combination with laser spot swinging, and the deposition efficiency is improved. The heating range of the composite heat source is expanded through the coupling effect of swing laser and electric arc, sufficient fusion of the side wall is ensured, meanwhile, bubble discharging is promoted through molten pool stirring, grains are refined, and the welding seam quality is improved. The laser and the MIG electric arc form a composite energy field, the auxiliary welding wire is directly melted, the energy utilization rate is remarkably improved, the deposition amount in unit time is increased by 30%-50%, the single-layer single-pass welding thickness can reach 3 mm-5 mm, the welding passes are reduced compared with a traditional MIG fuse wire mode, and the method is suitable for efficient and high-quality thick plate welding.

The invention discloses a production method of thick-wall pipeline steel X65MS for polar regions, which adopts ultra-low carbon and high Ni + casting blank secondary cogging extreme cooling + steel plate online ultrafast cooling, breaks the component design of the conventional pipeline steel standard, solves the problem of poor drop hammer low-temperature toughness of thick-wall acid-resistant pipeline steel at-55 DEG C, and has the transverse and longitudinal yield strength of 460-560MPa, the tensile strength of 590-650MPa, the yield ratio of less than or equal to 0.80, the tensile strength of 590-650MPa and the tensile strength of less than or equal to 0.80. The uniform elongation is 10%-12%, the impact value at-55 DEG C is 400-500 J, and the drop weight at-55 DEG C is 90%-95%; when the product is soaked in an NACE solution for 96 hours in an HIC test, CLR, CTR and CSR are all 0; sSC test: four-point bending constant load nominal yield is 90%, and the sample is soaked for 720 hours, and the surface of the sample has no crack; the CTOD value of the crack tip opening displacement of the CTOD test material at-55 DEG C is greater than or equal to 0.6 mm.

The invention discloses a thick-wall pipe welding residual stress ultrasonic detection and high-energy acoustic beam regulation and control device and method, and the device comprises a mounting mechanism which is provided with a plurality of mounting plates, the plurality of mounting plates are arranged in a straight line, and every two adjacent mounting plates are hinged; the high-energy ultrasonic exciter is mounted on the at least one mounting plate; and the fixing mechanisms are installed on the two installation plates at the two ends of the installation mechanism and used for fixing the multiple installation plates of the installation mechanism in the circumferential direction of the inner side surface or the outer side surface of the thick-wall pipe. The high-energy ultrasonic exciter is controlled to emit ultrasonic waves during welding, so that the residual stress of the welding position can be reduced and homogenized. And after welding is completed, the residual stress of the welding position is detected, when the residual stress exceeds a preset value, the high-energy ultrasonic exciter is controlled again to send out the ultrasonic waves to reduce and homogenize the residual stress of the welding position, and the process is finished until the residual stress of the welding position is detected to be smaller than or equal to the preset value.

The invention provides a multi-laser multi-axis feeding additive manufacturing device and an additive manufacturing method, and belongs to the field of wire-based additive manufacturing. The multi-laser multi-axis feeding additive manufacturing device comprises a first wire feeding guide mechanism and a second wire feeding guide mechanism which move synchronously; the laser emitting assembly emits at least two laser beams; the guide axis of the first wire is perpendicular to the surface of the platform; the guide axis of the second wire is inclined to the surface of the platform; the two groups of laser beams are respectively distributed around the guide axes of the two first wires and irradiate on the platform to form two groups of multiple light spots around the guide axes of the first wires, and each group of light spots has parts which are overlapped at the same time in the group and fall onto the tail ends of the first wires; each group of light spots has a portion that does not overlap in the group and overlaps with the outer group and falls onto the end of the second wire. The printing quality is mainly guaranteed through coaxial wire feeding, paraxial wire feeding is selectively carried out according to the thickness of a printing part of a component, the forming quality is improved by using coaxial double wire feeding at a thin wall, and the forming efficiency is effectively improved by adding paraxial single wire feeding at a thick wall.

The invention relates to the technical field of die-casting dies, and discloses a partitioned differential temperature cooling die-casting die for a complex aluminum alloy shell, which comprises a die body, and a thick-wall region, a thick-wall transition region and a thin-wall region are arranged in the die body; the mold body is provided with independent cooling units corresponding to the thin-wall area, the thick-wall transition area and the thick-wall area respectively, and each cooling unit is communicated with a cooling liquid transmission pipe through a self-adaptive sealing anti-leakage structure; thin-wall area cooling pipes arranged in a Z shape are installed on the outer side of the thin-wall area in an attached mode, spiral thick-wall transition area cooling pipes are installed on the outer side of the thick-wall transition area in an attached mode, and thick-wall area cooling pipes with built-in spoilers are installed in the thick-wall area in an embedded mode. According to the partitioned differential temperature cooling die-casting die for the complex aluminum alloy shell, through the partitioned independent temperature control cooling unit, the self-adaptive sealing anti-leakage structure and surface strengthening treatment, accurate cooling of regions with different wall thicknesses is achieved, the product forming quality is improved, the die universality is enhanced, the service life of the die is prolonged, and the maintenance cost is reduced.

The invention relates to the technical field of plastic injection molding, in particular to a multi-point glue feeding method for a thick-wall light-emitting body of an automobile tail lamp and an injection molding mold, and the method comprises the steps that product parameters are obtained in response to a detection signal, and a correlation coefficient, a guide angle and a reference track are determined according to the product parameters; injecting the magnetic ball and the detection liquid from a pouring gate position at a guide angle based on a track control method, and collecting a moving track; when the moving track does not coincide with the reference track, an adjusting coefficient is determined according to the moving track and the reference track, and the guide angle is corrected; when the moving track coincides with the reference track, defining the guide angle as a target angle; the injection molding angle is determined according to the target angle and the correlation coefficient, molten plastic is injected from the sprue position, and then a connection image of the product is collected; and the injection molding angle is corrected according to the existence condition of the cross color feature in the connection image. The device has the effect of avoiding color crossing of two materials in a product.

The invention discloses a weldless integral high-strength feeding drill rod and a preparation method thereof. The drill rod comprises a female connector, an elevator groove, a thick-wall slip clamping section, a drill rod pipe body and a male connector which are integrally formed and have the same inner diameter. The drill rod is manufactured by integrally machining a solid bar or a thick-wall pipe body. The yield strength of the drill rod pipe body, the yield strength of the thick-wall slip clamping section and the yield strength of the elevator groove are 135 ksi-180 ksi, and the yield strength of the male connector and the yield strength of the female connector are 130 ksi-150 ksi; the outer diameter of the thick-wall slip clamping section is larger than that of the drill rod pipe body; the outer diameter of the elevator groove is smaller than that of the clamping section of the thick-wall slip; the outer diameter of the elevator groove is not smaller than that of the drill rod pipe body. The outer diameter of the connector does not need to be obviously increased, meanwhile, enough elevator lifting capacity is guaranteed, and the problem of poor structure performance caused by friction welding seams and welding area heat treatment is avoided. Complicated welding, postweld heat treatment and other procedures are omitted, the possibility that a weld joint serves as a performance weak link is avoided, higher comprehensive tensile mechanical performance is achieved, and the method is suitable for well drilling application of extra-deep wells, ocean deep wells and the like.

The invention discloses a chamfering and beveling machine for a welding junction of a thick-wall pipeline, and relates to the technical field of pipeline machining equipment. Comprising a machining base, supports are symmetrically and fixedly mounted at the top of the machining base, a mounting frame is slidably mounted at the end of the machining base, a first limiting groove and a second limiting groove are formed in the surface of the mounting frame, a first lead screw is rotatably mounted on the inner wall of the first limiting groove, and a second lead screw is rotatably mounted on the inner wall of the second limiting groove; a first U-shaped frame is fixedly installed at one end of the limiting block, a driving wheel is rotatably installed on the surface of the first U-shaped frame, a second limiting block is slidably connected to the inner wall of the second limiting groove in a sleeved mode, a second U-shaped frame is fixedly installed at the end of the second limiting block, and a rolling wheel is rotatably installed on the surface of the second U-shaped frame. The second lead screw is of a symmetrical structure with the first lead screw as the center, and the second lead screw and the first lead screw are in gear transmission. A groove cutter is arranged between the two second U-shaped frames. And the groove does not need to be ground manually, the grinding process is more stable, and the forming effect of the groove of the thick-wall pipeline is improved.

The invention provides a narrow-gap laser welding method and device for a thick-wall material, and the method comprises the following operation steps: S1, after a narrow-gap groove is formed in a to-be-welded workpiece, an upright-focal flat-topped laser beam emitted by a laser head acts on the bottom and the side wall of the narrow-gap groove, a flux-cored wire fed into the groove is melted, molten drops are formed and are transited to a molten pool, and the narrow-gap groove is formed; filling the groove and solidifying to form a filling layer; s2, a laser sensor is used for obtaining the original geometrical shape of the weld joint, and the weld joint groove morphology with feature points is extracted through coordinate transformation and visual image analysis; s3, the shape of the weld groove is converted into a geometrical shape under a welding robot coordinate system through a control unit, the position of the welding robot is adjusted according to the depth and width of the groove, and it is ensured that the distances between the flux-cored wire and the two sides of the groove are the same; according to the method, the welding quality and the welding efficiency can be improved, the stability of the welding process can be remarkably improved, the incomplete fusion defect of the side wall is reduced, and therefore self-adaption and automatic welding of large-thickness materials are achieved.

The invention discloses thick-wall metal plate cutting equipment, and relates to the technical field of metal plate cutting, the thick-wall metal plate cutting equipment comprises a working platform, a supporting cushion block, a plurality of supporting columns, a longitudinal feeding module, a stand column, a transverse feeding module, a cutting module, a cooling module, a slag cleaning module and a control panel, a plurality of supporting cushion blocks are arranged on the working platform, the longitudinal feeding module is connected with the working platform and fixed to the working platform, the two ends of the working platform are connected with the stand columns correspondingly, the two stand columns are oppositely arranged, and the bottoms of the stand columns are in sliding connection with the working platform and are in threaded connection with the longitudinal feeding module. The top end of the stand column is fixedly connected with the transverse feeding module, the transverse feeding module is connected with the cutting module, the cooling module is arranged on the cutting module, the transverse feeding module is connected with the slag cleaning module, the control panel is connected with the transverse feeding module, and the control panel is fixed to the face, close to the longitudinal feeding module, of the transverse feeding module.

The utility model discloses large-caliber thick-wall elbow stamping equipment which comprises a bottom plate and a top plate, the bottom plate and the top plate are connected through stand columns, a lower die assembly is arranged on the bottom plate, an upper die assembly is arranged on the top plate, and the lower die assembly comprises a lower die frame, two sets of lower die bases and two sets of bearing tables. The upper die assembly comprises two sets of upper die bases, a through groove is formed in the bearing table, multiple sets of positioning columns are arranged on the bearing table, the multiple sets of positioning columns form a positioning area, a plate is placed in the positioning area, hydraulic cylinders are arranged on the two sides of the bottom plate correspondingly, and the hydraulic cylinders are used for driving the bearing table to move in the axial direction. The two sets of lower die bases and the two sets of upper die bases jointly form two sets of punch forming positions, two sets of formed parts can be punched at a time, and the punch forming efficiency of punching equipment is improved; and after punch forming, the hydraulic cylinder jacks up and resets the bearing table, and the bearing table jacks up the formed part synchronously, so that the formed part is separated from the male die, and demolding is achieved.

The invention relates to a casting method for a low-pressure alloy casting of a riser-free sand mold. The casting method comprises the steps that molten alloy is injected into a casting cavity through a plurality of flow gates in the bottom of the casting cavity in a low-pressure mode for mold filling; during mold filling, the variable-diameter air outlet needle arranged above the casting cavity is used for exhausting air; after mold filling is completed, stepped pressurization and pressure maintaining are conducted on the molten metal in the casting mold cavity; and when the casting is solidified, the thick and large part at the top of the casting cavity is cooled in an accelerated manner, so that the casting is solidified from bottom to top and from the thin-wall area to the thick-wall area. Through bottom multi-pouring-gate mold filling and top variable-diameter gas outlet needle gas exhausting, splashing is prevented. And step pressurization and pressure maintaining are carried out after mold filling, and a thick-wall area is forcibly fed. During solidification, solidification is formed from bottom to top and from thin to thick. A riser is replaced with pouring gate feeding, precise exhaust and solidification control are combined, the feeding and exhaust problems of riser-free casting are solved, riser cutting and polishing are avoided, and meanwhile it is guaranteed that a casting is compact and high in quality.

The invention provides a thick-wall austenitic stainless steel full-focus correction imaging method based on a TRL probe, and the method comprises the steps: collecting a thick-wall austenitic stainless steel welding seam based on a TRL area array probe, obtaining full-matrix data, measuring an elastic stiffness matrix of a welding seam material, and solving a wave equation of ultrasonic waves based on the elastic stiffness matrix, the method comprises the following steps: acquiring a phase velocity and a group velocity, acquiring the magnitude and the direction of the phase velocity and the group velocity, calculating a propagation path of ultrasonic waves in an anisotropic medium based on a ray tracing technology and in combination with a Fermat principle, extracting an amplitude value of a corresponding moment from full matrix data according to propagation time, performing delay superposition on each imaging point in an imaging area, and completing correction of full-focus imaging. According to the thick-wall austenitic stainless steel welding seam correction imaging method based on the TRL area array probe, the detection precision of an imaging result and the detection signal-to-noise ratio are improved, and a more reliable and accurate technical scheme is provided for thick-wall austenitic stainless steel welding seam detection.

The invention discloses an integral swinging self-resetting system with an asymmetric structure and a construction method thereof. The integral swinging self-resetting system comprises an upper structure, a lower structure and a swinging layer arranged between the upper structure and the lower structure, the plane structure of the upper structure is a non-axisymmetric structure; the swinging layer comprises a plurality of vertical elastic supports, and the plurality of vertical elastic supports are arranged at the bottom of the upper structure at intervals; the vertical elastic support comprises an upper connecting steel plate, a lower connecting steel plate, a spring and an energy consumption limiting piece; the upper connecting steel plate is arranged right above the lower connecting steel plate, the upper connecting steel plate is connected with a bottom steel sleeve arranged at the bottom of an upper structure, and the lower connecting steel plate is connected with a lower structure; the upper and lower ends of the spring are respectively welded on the upper and lower connecting steel plates; the energy consumption limiting piece comprises an upper thick-wall sleeve, a lower thick-wall sleeve and a limiting sleeve. The vibration isolation device solves the technical problems that a traditional vibration isolation device is often difficult to achieve the horizontal vibration isolation effect and the vertical vibration isolation effect at the same time, and the isolation effect of the traditional vibration isolation device is not ideal for high-frequency vibration caused by metros and the like.

The invention provides a method for acquiring the continuous curvature of a segmented variable cross-section tower drum structure of an offshore wind turbine, and belongs to the technical field of ocean engineering structure monitoring based on computer data processing. Comprising the following steps: acquiring discrete strain data of the inner surface of a measurement point of a segmented tower tube structure in real time; obtaining the discrete curvature data of the inner surface of the tower drum through the strain data and the wall thickness of the measurement point; interpolating the discrete curvature data subsets of the measuring points into an inner surface continuous curvature function; verifying the continuous curvature function of the inner surface according to the check points; deriving a continuous curvature function of the outer surface of the tower drum through the curvature function of the inner surface and the wall thickness; and all the segments are repeated, and a global curvature function of the whole tower structure is constructed. According to the method, the curvature of the outer surface is strictly derived from the continuous curvature of the inner surface, so that approximate errors of a traditional thin-wall beam theory in a segmented variable cross-section, thick-wall or large-deformation scene are fundamentally avoided, and the overall deformation state of the tower drum is more truly restored.

The invention provides low-temperature cast steel for polar ships and a heat treatment process of the low-temperature cast steel. The cast steel comprises the following chemical components in percentage by weight: 0.03-0.07% of C, 0.10-0.20% of Si, 1.3-1.5% of Mn, 3.0-4.0% of Ni, 0.80-1.00% of Al, 1.5-2.5% of Cu, not more than 0.05% of Cr and Mo, not more than 0.015% of S, not more than 0.020% of P and the balance of Fe and inevitable impurities. The cast steel has the advantages of ultra-large wall thickness, high strength, low-temperature high toughness, weldability, corrosion resistance and the like, and can meet the building requirements of polar region ship stem columns.

The invention belongs to the technical field of building construction, and provides a super-thick wall concrete crack control method, which comprises the following steps: acquiring a wall three-dimensional solid model, dividing the wall three-dimensional solid model into grid units to obtain a finite element model, monitoring the pressure of a heat dissipation steel pipe by using a pressure sensor network, and judging whether the bond stress of concrete to the steel pipe is abnormal or not; if the grid units are normal, temperature parameters of the grid units are calculated through a temperature sensor network, whether a cooling circulation system is started or not is judged, if yes, temperature control targets of the grid units are simulated and calculated, and prediction time periods are marked for the grid units according to the cooling parameters of the cooling circulation system; constructing a hybrid prediction model to predict the unit temperature of the grid units in the prediction time period to obtain a predicted unit temperature sequence of each grid unit, dynamically calculating an adjustment value of the cooling parameter through a PID algorithm, and performing feedback iterative calculation according to the adjustment value to obtain an actual adjustment value of each cooling parameter; and the cooling parameter is adjusted according to the actual adjustment value.

The invention relates to the technical field of non-cutting machining of metal pipes, in particular to large-diameter thick-wall pipe electric heating hole shrinkage equipment and a hole shrinkage method thereof. The large-diameter thick-wall pipe electric heating hole shrinkage equipment comprises a workbench, hole shrinkage molds, driving units, a pipe clamping device and a supporting inner core system, wherein the hole shrinkage molds and the driving units are symmetrically arranged. The supporting inner core is composed of main core rods, an auxiliary core rod and a reset piece, the installation sinking grooves of the two main core rods are arranged in a staggered mode in the circumferential direction, the auxiliary core rod is matched with the guide inclined face of the fine adjustment inserting plate through a movable sliding groove, and the auxiliary core rod is promoted to be unfolded in the radial direction to support the middle of a pipe when the diameter reducing dies move oppositely. The electric heating device is arranged to reduce deformation resistance of the pipe, the inner wall lubricating device and the outer wall lubricating device spray lubricating liquid to the inner wall and the outer wall of the pipe to reduce friction damage in the machining process, and the lubricating liquid collecting device achieves environment-friendly recovery of redundant lubricating liquid. According to the device, all-directional supporting, temperature control and precise stroke adjustment of the pipe in the diameter reducing process are achieved.

The utility model discloses a transportation pulling rope quick connecting device which comprises a steel wire mesh sleeve, a locking piece and a clamping sleeve, the diameter of the steel wire mesh sleeve is matched with that of a transportation pulling rope, the locking piece is a hollow cylinder with the wall thickness not smaller than 2mm, the inner diameter of the locking piece is larger than the sum of the outer diameter of the transportation pulling rope and the double diameter of a steel wire of the steel wire mesh sleeve, and the clamping sleeve is connected with the steel wire mesh sleeve. The outer circle surface of the jacket is smooth, the two ends of the jacket are chamfered, a through threaded hole is formed in the center of the cylindrical surface of the jacket, the inner diameter of the jacket is smaller than the outer diameter of a transportation traction rope, the steel wire mesh sleeve can freely penetrate through the jacket in the initial state, the outer circle surface of the jacket is smooth, the two ends of the jacket are chamfered, and the two ends of the inner circle are subjected to arc guiding treatment. The clamping sleeve enables the steel wire mesh sleeve to radially contract towards the middle when the steel wire mesh sleeve is tensioned, the friction force between the steel wire mesh sleeve and a transportation traction rope is increased, and the effect that the steel wire mesh sleeve is tensioned more and more tightly is achieved. Due to the fact that the steel wire mesh sleeve is large in flexibility, the steel wire mesh sleeve can smoothly pass through a winch without causing deformation and damage at the joint.

The invention discloses a spinning forming method for a thick-wall aluminum alloy cylindrical structure, belongs to the technical field of material processing, and aims to solve the problems that in the prior art, a thick-wall aluminum alloy component is high in economic cost, the process is complex and difficult to control, and a large-diameter thick-wall part cannot be processed. The spinning forming method is realized by designing a blank, determining a spinning pass and a thinning rate, debugging spinning equipment and installing the blank, performing for the first pass of thermal strong spinning, performing for the second pass of thermal strong spinning, and machining. The technical problems that the wall thickness reduction rate of a large thick-wall conical structure is large, forming is difficult, hot spinning forming precision is difficult to control, and annealing deformation is large are solved. The large-diameter thick-wall part can be machined, the manufacturing cost is saved, and manpower and material resource consumption is reduced. And meanwhile, the defects of high raw material consumption, unstable product mechanical property and the like are overcome, and the problems of unstable product quality and the like in the production process are fundamentally avoided.

This invention provides a method for producing small-diameter, thick-walled near-α-type titanium alloy tubing and its application. This method, through the use of cladding and heated rolling, increases the deformation per rolling pass, reduces the number of rolling passes, and results in a finer microstructure and better mechanical properties in the heated-rolled tubing. Simultaneously, the composite material composed of the cladding layer and silica aerogel effectively prevents the alloy rod from contacting air, avoiding further surface oxidation and reducing the thickness of the oxide layer on the rod surface. Furthermore, the composite material forms a "thermal insulation layer" on the surface of the alloy rod, preventing large temperature differences between the surface and core during heated rolling, thus ensuring better microstructure uniformity and surface quality. In this invention, the cladding process expands the selection of heating furnaces and reduces equipment requirements.

The invention relates to the technical field of image processing, in particular to a defect detection method for a solid thick-wall section profile machining mold. The method comprises the following steps: acquiring a target image of a processing mold; carrying out local division on the target image, and carrying out local enhancement; extracting an edge skeleton from the enhanced image, obtaining a frequency spectrum coefficient, determining a low-frequency energy concentration ratio based on the frequency spectrum coefficient, and screening irregular shape regions; in the irregular shape area, based on the dispersion degree of the gradient direction of the pixel points around the target point, the arc length of the contour skeleton, the curvatures of all the pixel points and the radian increment between the adjacent pixel points are combined to obtain a defect distinguishing value; further screening oxidation defects and crack defects; and marking training models for the two defects, and carrying out real-time defect detection through the models. According to the method, two defects are accurately distinguished, and the defect detection precision is improved.

The invention relates to a process forming method for a large thick-wall special-shaped curved surface carbon steel stainless steel shell. According to the process forming method, it is ensured that the high-precision molded surface size of the special-shaped curved surface shell is achieved in the forming process through multi-link optimization control. On the basis of allowance amplification optimization of three-dimensional modeling and expansion, by combining numerical control cutting and leveling processes, simulating a cutter pressing line path through software, and performing trial-manufacturing verification by using equal-proportion sample pieces; line-by-line and tool-by-tool pressing and two times of shaping inspection are adopted in the step-by-step pressing process, and the local deformation amount is corrected in real time; in the pre-assembly stage, the goodness of fit of assembly lines is ensured through three-dimensional lofting and scribing and tool positioning, and welding thermal deformation and residual stress are effectively controlled in cooperation with anti-deformation tool welding and aging treatment. Digital simulation, parameter iterative optimization, process error compensation and mechanical stability control are fused in the whole process, so that the profile precision of the shell meets the design requirement in the cold forming stage, and relying on machining correction is avoided.

An expandable introducer (100) includes a hub (110) having a distal end (114) and a proximal end (112), and a sheath (120) coupled to the hub and extending distally therefrom, the sheath defining a central lumen (125). The sheath is configured to radially expand from a radially unexpanded, folded state having a first diameter and to a radially expanded, unfolded state having a second diameter larger than the first diameter in response to a device passing through the central lumen. A wall (150) of the sheath includes a thick wall region (146) having a first wall thickness and a thin wall region (144) having a second wall thickness smaller than the first wall thickness, wherein the thick wall region includes a coil (160) embedded within the wall of the sheath.

The invention provides a preparation method of a surface layer shell for precise casting production of a thick-wall titanium alloy. The preparation method comprises the following steps: S1, preparing a surface layer binder, wherein the surface layer binder comprises modified silica sol, a stabilizer, a reinforcing agent, a wetting agent and an acid-base regulator; the modified silica sol is diluted sodium-stabilized alkaline colloidal silicon dioxide; s2, preparing surface layer refractory powder, wherein the surface layer refractory powder comprises yttrium oxide powder, zirconium oxide powder and calcium fluoride powder; s3, preparing a surface layer coating; adding the surface layer refractory powder in the step S2 into the surface material binder in the step S1; s4, preparation of a surface layer shell, specifically, a module for preparing the surface layer shell enters the surface layer coating in the S3 to be subjected to slurry hanging, sand spraying and drying, and the step is repeated 1-2 times; and S5, the surface layer shell in the step S4 is subjected to firing forming, and the surface layer shell for precise casting production of the thick-wall titanium alloy is obtained. The surface layer shell obtained through the preparation method can be used for producing titanium alloy castings with the wall thickness ranging from 25 mm to 50 mm.