816 results about "Weldability" patented technology

The high-steel-grade low-cost hot-rolled coil plate comprises the following chemical components: 0.040 to 0.065 percent of C, 0.20 to 0.35 percent of Si, 1.48 to 1.75 percent of Mn, less than or equal to 0.02 percent of P, less than or equal to 0.003 percent of S, 0.012 to 0.025 percent of Ti, 0.035 to 0.055 percent of Nb, 0.005 to 0.008 percent of RE, 0.15 to 0.20 percent of Cr, 0.0005 to 0.0020 percent of B, 0.002 to 0.004 percent of Mg, 0.025 to 0.050 percent of Als, less than or equal to 0.003 percent of Ca, less than or equal to 0.008 percent of N and the balance of Fe and inevitable impurities. The technological process comprises the steps of smelting, slab continuous casting, slab heating, rolling, cooling and coiling. Rt0.5 of the steel is 580-660 MPa, Rm is 650-750 MPa, A50 mm is larger than or equal to 28%, Rt0.5 / Rm is smaller than or equal to 0.90, the impact energy mean value Akv at the temperature of-40 DEG C is larger than or equal to 200 J, the drop weight DWTT mean value at the temperature of-20 DEG C is larger than or equal to 90%, the hardness value HV10 is smaller than or equal to 220, and the cold bending performance is qualified. The product provided by the invention has high strength and toughness and good welding performance, so that the product is more suitable for various complex and extreme service environments, and has higher safety in pipeline engineering.

The invention discloses 700Mpa-grade hot-rolled wheel steel and a preparation method thereof, and belongs to the technical field of metallurgy. The steel for the wheel comprises the following chemical components in percentage by mass: less than or equal to 0.1% of C, 0.05-0.10% of Si, less than or equal to 1.65% of Mn, less than 0.015% of P, less than 0.005% of S, less than 0.060% of Nb, less than 0.020% of Ti, less than 0.03% of Cr, less than 0.045% of A1s, less than 0.005% of N, less than 0.003% of O and the balance of iron and inevitable impurities. The production method comprises the procedures of molten iron pretreatment, converter smelting, LF refining, RH refining, slab continuous casting, heating, rolling, laminar cooling and coiling. Under the condition that expensive Mo element is not added, through reasonable component design and a controlled rolling and controlled cooling process, the yield strength of the wheel steel is larger than or equal to 500 MPa, the tensile strength is larger than or equal to 680 MPa, the ductility is larger than 18%, and the wheel steel has good welding performance and machining performance.

The invention relates to a P690QL2 steel plate with ultrahigh die welding and low-temperature performance and a manufacturing method of the P690QL2 steel plate. The P690QL2 steel plate comprises the following chemical components in percentage by weight: 0.04%-0.12% of C, 0.02%-0.08% of Si, 1.0%-1.2% of Mn, 1.5%-2.5% of Ni, 0.3%-0.7% of Cr, 0.7%-0.9% of Mo, 0.07%-0.12% of V, 0.02%-0.04% of Ti, less than or equal to 0.002% of S, less than or equal to 0.002% of P, 0.03%-0.06% of Als and the balance of Fe and inevitable impurity elements. The steel plate is applied to the liquid cargo tank of the LCO2 transport ship, has high strength and low-temperature toughness requirements, is easy to weld and has ultrahigh die welding performance, the V-type impact energy of the steel plate at-60 DEG C is larger than or equal to 150 J, the CTOD at-55 DEG C is larger than 0.2 mm, and the machining and welding use requirements of pressure-bearing equipment are met.

The invention belongs to the technical field of welding devices, and particularly relates to an electric actuator shell automatic welding device which comprises a mounting frame, a supporting frame is fixedly connected to the upper side wall of the mounting frame, a control cabinet is fixedly connected to the side wall of the supporting frame, and a vertical electric push rod is fixedly connected to the upper side wall of the supporting frame. The moving end of the vertical electric push rod penetrates through the supporting frame. When the nameplate is welded to the surface of the electric actuator in a spot welding mode, the welding strength of the nameplate can be automatically detected, and when insufficient welding of a nameplate welding spot is detected, an operator can be timely reminded to carry out repair welding on the nameplate, so that the welding strength of the nameplate is guaranteed, and the welding efficiency of the nameplate is improved. And when four welding spots of the nameplate are detected, the abrasion degree of the welding electrode on the side can be analyzed by recording the frequency of pseudo soldering of a certain welding spot, and then the abraded welding electrode is polished, so that the welding performance of the welding electrode is ensured.

The invention discloses a production method of a 15CrMoR steel plate for rare earth microalloying hydrogen-contacting equipment with excellent high-temperature performance. The production method comprises the steps of KR desulfurization, converter smelting, LF refining, RH refining, continuous casting, slow cooling in a heat preservation pit, heating, rolling, cooling, hot straightening, shearing, flaw detection, normalizing and tempering. The steel comprises the following chemical components in percentage by mass: 0.15-0.17% of C, 0.20-0.30% of S i, 0.50-0.60% of Mn, less than or equal to 0.012% of P, less than or equal to 0.005% of S, 0.019-0.029% of Al s, 0.9-1.1% of Cr, 0.50-0.60% of Mo, less than or equal to 0.0020% of Ce, less than or equal to 1.5 ppm of H, less than or equal to 0.0040% of O, less than or equal to 0.0060% of N and the balance of Fe. And the balance of iron impurities. A normalizing and tempering heat treatment process is adopted, and a low-carbon component design is adopted to ensure that the steel plate obtains excellent high-temperature performance and welding performance.

The invention relates to the technical field of electronic paste, in particular to copper electrode paste for an NTC thermistor and a preparation method and application of the copper electrode paste. A copper electrode slurry for an NTC thermistor comprises copper powder, an inorganic glass binder, an organic carrier and a dispersant, the inorganic glass binder comprises CuO and NiO, and the organic carrier comprises a polymer thickener. The copper electrode slurry can be coated on the surface of an NTC thermistor ceramic substrate through a silk-screen printing method, can be used as a metallized conductive layer after being sintered in nitrogen, is used for temperature measurement, temperature compensation, temperature control components and the like, and is wide in application. The copper electrode slurry for the NTC thermistor provided by the invention can be sintered in nitrogen at 550-650 DEG C, and has the advantages of wide sintering interval, good sintering appearance, excellent welding performance and strong adhesive force. After sintering, the ohmic contact is good, so that the prepared NTC thermistor can truly reflect the resistance value of a substrate, and the phenomenon of ion migration is avoided.

The invention relates to 500MPa-grade preheating-free welding structural steel and a preparation method thereof, belongs to the technical field of structural steel, and solves the problems that in the prior art, traditional structural steel is poor in welding performance, high in carbon equivalent, high in cold crack sensitivity and difficult to consider both high strength and good plasticity. The structural steel comprises the following chemical components in percentage by weight: less than 0.002% of C, less than 0.02% of Si, less than 0.03% of Mn, 1.5-2.0% of Ni, 1.5-2.0% of Cu, less than 0.0008% of S, less than 0.006% of P and the balance of Fe and inevitable impurities, wherein the carbon equivalent Ceq is less than or equal to 0.27. The combination of high strength (the yield strength is larger than or equal to 550 MPa, and the tensile strength is larger than or equal to 650 MPa), excellent welding performance (Pcm is smaller than or equal to 0.14), good plasticity (the percentage elongation after fracture is larger than or equal to 25%, and excellent low-temperature toughness (the impact energy at the temperature of-20 DEG C is larger than or equal to 200 J) is achieved, and the steel is suitable for the structural fields of ships, bridges, buildings and the like with strict requirements for welding performance and mechanical performance.

The invention discloses a fabricated steel-UHPC external prestressing combined box girder and a construction method and application thereof, and relates to the technical field of bridge engineering, the fabricated steel-UHPC external prestressing combined box girder comprises a prefabricated steel-UHPC combined top plate, a prefabricated steel-UHPC combined bottom plate, a prefabricated steel-UHPC combined web plate, a steel diaphragm plate and an external prestressing system. The box girders are formed by combining prefabricated slabs, the prefabricated web plates are firmly connected with the prefabricated top plate and the prefabricated bottom plate through welded steel plates and post-poured UHPC, and arrangement and tensioning of external prestress are achieved by arranging steel anchor boxes and steering gears in box chambers. According to the combined box girder, the steel and the UHPC are combined to form a structural form that the steel plate is wrapped by the UHPC, and the advantages of high strength, high durability, high toughness, high compactness, low creep and the like of the UHPC and the advantages of high strength, high elastic modulus and weldability of steel are fully utilized, so that the box girder has the advantages of being excellent in structural stress performance, light in overall weight, good in durability, small in later-stage deformation, low in cost and the like. And the hoisting device is especially suitable for bridges in urban rail transit or urban railways.

The invention relates to the technical field of alloys, in particular to a weldable high-temperature corrosion-resistant nickel-based alloy and a preparation process thereof. The nickel-based alloy comprises Cr, Mo, W, Ti, Al, Nb, Co, B, Zr, La, C, Si, Mn, P, S and the balance Ni and inevitable impurities. The element content meets the following conditions: Al + 0.5 Ti + 0.3 Nb is greater than or equal to 3.35 wt.% and less than or equal to 3.8 wt.%, the volume fraction of the gamma'phase is correspondingly 28-34%, and the electron vacancy number Nv is less than 2.6. According to the preparation process, VIM and PESR duplex smelting, multi-pass forging, solid solution rapid cooling and aging heat treatment are adopted, and the welding process is optimized in a matched mode. The alloy has excellent welding performance while maintaining excellent high-temperature strength and corrosion resistance, and is particularly suitable for high-temperature parts needing to be welded in the fields of aerospace, energy, chemical industry and the like.

The invention discloses a lightweight ultrahigh-strength high-modulus weldable aluminum-lithium alloy material and a preparation method thereof. The aluminum-lithium alloy comprises 3.20 wt%-3.49 wt% of Cu, 1.45 wt%-1.75 wt% of Li, 0.35 wt%-0.50 wt% of Mg, 0.20 wt%-0.40 wt% of Ag, 0.11 wt%-0.17 wt% of Sc, at least one of Zr, Mn, Ti, Hf and V with the total content not larger than 0.60 wt%, the balance Al and inevitable impurities, each impurity element is smaller than or equal to 0.15 wt%, and the sum of the impurity elements is smaller than or equal to 0.40 wt%. The preparation method of the alloy deformation processing material comprises the following steps: (1) manufacturing an aluminum-lithium alloy ingot blank; (2) homogenizing heat treatment; (3) thermally processing the ingot blank into a required processing material or a pre-processing material; (4) optionally reheating the pre-processing material, and processing the pre-processing material into a required processing material through cold deformation; (5) carrying out solid solution heat treatment on the processing material; (6) the machined material subjected to solution heat treatment is rapidly cooled to the room temperature; and (7) aging treatment is conducted on the machined material. The aluminum-lithium alloy material shows excellent comprehensive performance of low density, high strength, high modulus, weldability and the like.

The invention relates to the technical field of metallurgy, in particular to a hot galvanizing low-alloy high-strength steel plate which comprises the following chemical components in percentage by mass: 0.06%-0.08% of C, 0.20%-0.25% of Si, 1.20%-1.35% of Mn, less than or equal to 0.015% of P, less than or equal to 0.005% of S, 0.020%-0.060% of Alt, 0.035%-0.050% of Nb, 0.010%-0.020% of Ti, less than or equal to 0.0050% of O, less than or equal to 0.0060% of N and the balance of Fe and inevitable impurities. The contents of C, Si and Mn in the chemical components are controlled, the welding performance of the hot-dip galvanizing low-alloy high-strength steel and the surface quality of a finished product are considered, Nb microalloying is mainly adopted, a proper amount of microalloy element Ti is added to form TiN, austenite grain coarsening is limited in the slab heating and heat preservation process, and fine and dispersed precipitated phases are finally obtained in combination with process control; the hot-dip galvanized low-alloy high-strength steel finished product is good in structure form and excellent in comprehensive performance.

A hot-stamped coated steel part includes a steel substrate and an aluminum alloy coating comprising, proceeding from steel substrate outwards, an interdiffusion layer and an outer layer. The total thickness of the coating ecoating and the thickness of the interdiffusion layer eIDL satisfy the following condition:40≤Ep⁢c≤8⁢0withEpc=(3⁢3.3-eIDL0.9+eIDL-ecoating)2-1⁢4⁢8⁢(eIDL-ecoating)-(3⁢3.3-eIDL0.9+eIDL-ecoating)The hot-stamped coated steel part comprises an undeformed portion having a thickness ePflatfrom 0.6 mm to 3.5 mm, and at least one deformed portion. A lineic density of cracks dC in the coating in the undeformed portion is higher than or equal to a minimum lineic density of cracks dCmin(ePflat) defined as:dCmin(epflat)=1⁢5.5+9⁢1*e-7.44-2.88*arctan⁡(5.49*(epflat-1.7⁢1))-106.5*e-8.62-3.3⁢4*arctan⁡(5.49*(epflat-1.71))

The invention relates to the field of building materials, in particular to nano-silver solder paste with high welding strength and a preparation method of the nano-silver solder paste. The nano-silver tin paste with high welding strength comprises the following raw materials: nano-silver powder, nano-tin powder, composite resin, a dispersing agent, an activating agent, a film-forming agent, a thixotropic agent, silicon-titanium particles, a stabilizing agent and the like. According to the nano-silver solder paste with the high welding strength and the preparation method thereof, uniform dispersion of an internal system is achieved, the welding effect and the welding performance are further optimized, the oxidation resistance can be greatly improved, the probability that high surface energy of nano-silver is prone to being oxidized to generate silver oxide is greatly reduced, and the welding quality of the nano-silver solder paste is improved. The silver solder paste prepared by the method further balances the balance between the preparation process and the high strength of the silver solder paste, and has excellent stability and mechanical strength, thereby meeting the requirements of high-reliability packaging in the prior art, and having wide application potential.

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 application belongs to the technical field of welding materials, and discloses a preformed soldering sheet and a preparation method thereof, the preparation method comprising: a flux preparation method, wherein benocyclobutene resin, a thixotropic agent, an active agent, a surfactant, an antioxidant, a corrosion inhibitor and a solvent are weighed, mixed and heated and stirred to mix, and then cooled to obtain the required flux; a processing method of a preformed soldering sheet body soldering strip, wherein lead-free filler metal is melted at high temperature to form a soldering strip; and a preformed soldering sheet preparation method, wherein the soldering strip is uniformly coated with the flux by a coating machine, and the flux is cured and attached to the soldering strip after baking; the preformed soldering sheet is obtained by the above preparation method. The application realizes improved welding quality of the soldering sheet coated with the flux film and solder metal oxidation resistance, and the preformed soldering sheet has high stability, good wettability and good weldability, and can meet the requirements of the market for the use of the preformed soldering sheet with low cavities.

Provided is a surface-treated steel sheet that can be produced without the use of hexavalent chromium and that combines excellent film corrosion resistance, coating corrosion resistance, film wet adhesion, coating secondary adhesion, and weldability. At least one side of the surface-treated steel sheet includes a Ni-containing layer, a metallic Cr layer on the Ni-containing layer, and an oxidized Cr layer on the metallic Cr layer. The water contact angle is 50° or less, and the total atomic ratio to Cr of K, Na, Mg, and Ca adsorbed on the surface is 5.0% or less.

The invention relates to a welding seam reinforcing structure for a stainless steel storage tank, and belongs to the technical field of aerospace carrier propellant storage tank structures. A first box bottom, a first short shell, a cylinder section, a second short shell and a second box bottom; the first box bottom and the second box bottom are each of a hemispherical shell structure. The first short shell, the second short shell and the barrel section are all of barrel section structures; the first short shell, the barrel section and the second short shell are horizontally and coaxially butted in sequence; the first box bottom is coaxially mounted at the axial outer end of the first short shell; the second box bottom is coaxially mounted at the axial outer end of the second short shell; the opening end of the first box bottom extends into the first short shell, and the outer wall of the first box bottom is in butt joint with the inner wall of the first short shell. The opening end of the second box bottom extends into the second short shell, and the outer wall of the second box bottom is in butt joint with the inner wall of the second short shell. The problem that the welding performance of reinforcing materials cannot be weakened through partition thickness design is solved, and the purposes of high performance, low cost manufacturing and the like of the stainless steel storage box are achieved.

The invention belongs to the field of steel pipes, and particularly relates to a method for manufacturing a cold drawn pipe, which comprises the following steps of: obtaining a raw material steel pipe which comprises the following elements in percentage by weight: less than or equal to 0.20 percent of C, less than or equal to 0.50 percent of Si, less than or equal to 1.70 percent of Mn, less than or equal to 0.025 percent of P, less than or equal to 0.035 percent of S, less than or equal to 0.30 percent of Cr, less than or equal to 0.50 percent of Ni, less than or equal to 0.10 percent of Mo, 0.05-0.15 percent of V and the balance of Fe; the method comprises the following steps: pretreating a raw material steel pipe, wherein the pretreatment sequentially comprises acid washing, alkali washing, water washing, phosphating, water washing and saponification; and carrying out cold drawing and annealing on the pretreated steel pipe to obtain the cold-drawn pipe. The invention also relates to the cold drawn pipe. According to the method disclosed by the invention, pollution between bath solutions in pretreatment is reduced, the surface quality after pretreatment is improved, and the upper yield strength, tensile strength and normal-temperature impact absorption energy of the cold-drawn pipe are improved, so that the cold-drawn pipe has relatively good toughness and welding performance.

The invention discloses a high-weldability modified TPU film and a preparation method thereof, and belongs to the technical field of high polymer material modification. The film comprises the following components: 100 parts by weight of TPU resin; 1-5 parts by weight of a filler with a particle size of 1-5 [mu] m after surface treatment; 0.5 to 1.2 parts by weight of an antioxidant; wherein the filler subjected to surface treatment is obtained by cleaning a filler raw material with an oxalic acid solution and coating the filler raw material with a titanate coupling agent for surface treatment. The filler subjected to surface treatment is added, and an optimized melt extrusion process is combined, so that the welding strength of the film is remarkably improved, the heat sealing stripping force is greatly improved, and the problem that a welding surface is easy to crack is thoroughly solved; meanwhile, the intrinsic performance of TPU is perfectly reserved, the elongation at break is maintained, the transparency decrease amplitude is small, the thermal aging resistance is excellent, and the double requirements for high-strength welding and flexibility maintaining in the fields of automobile sealing parts, electronic packaging and the like are completely met.

The invention relates to the technical field of power cables, and discloses a high-flexibility high-temperature-resistant fireproof cable which comprises a conductor, an insulating layer, a shielding layer, an inner sheath layer, a fireproof layer and an outer sheath layer which are sequentially arranged from inside to outside, the conductor is formed by twisting multiple strands of fine copper wires, the surface of each fine copper wire is plated with a layer of tin, the insulating layer is made of a silicon rubber material, and the shielding layer is made of a silicon rubber material. A nanoscale magnesium hydroxide flame retardant and a high-temperature-resistant additive are added into the silicone rubber material; the shielding layer is a copper wire braided shielding layer; the inner sheath layer is made of a polyurethane material; the fireproof layer comprises a ceramic silicone rubber layer and a mica tape wrapping layer which are arranged in sequence; according to the scheme, the conductor is stranded by multiple strands of fine copper wires, and the diameter, the stranding pitch and the tension are optimized, so that the cable keeps excellent flexibility in frequent bending and moving environments, and the conductor is prevented from being broken. The tin coating improves the oxidation resistance and the welding performance, and ensures the long-term stability of electrical connection.

The invention relates to the technical field of thermoplastic composite material welding, in particular to a composite material continuous ultrasonic welding method based on an interface microstructure, which comprises the following steps: carrying out positioning treatment on the surface of a thermoplastic composite material to be welded, and selecting welding parameters according to the property of the thermoplastic composite material to be welded; a microstructure texture is introduced into a to-be-welded interface of the thermoplastic composite material, and the microstructure texture has parameterized geometric properties; a flexible and continuous energy conduction item is arranged between the microstructure texture and the substrate on the opposite side, and molten resin is in a super-infiltration state in the initial welding stage through the ultrasonic vibration effect; and welding is completed under the set welding parameter condition. The welding performance of the thermoplastic composite material is improved, and a feasible technical path is provided for rapid assembly of complex structures in the future.

The invention discloses a high-uniformity extra-thick 420MPa-grade maritime work steel plate for an extremely low temperature environment and a manufacturing method thereof, and belongs to the field of ferrous metallurgy. The steel plate comprises the following chemical components in percentage by mass: 0.03%-0.07% of C, 0.15%-0.35% of Si, 1.40%-1.70% of Mn, less than or equal to 0.002% of S, less than or equal to 0.010% of P, 0.015%-0.045% of Als, 0.03%-0.05% of Nb, 0.10%-0.30% of Cr, 0.010%-0.020% of Ti and the balance of Fe and inevitable impurities, and the carbon equivalent CEV is less than or equal to 0.36%. The manufacturing process comprises the steps of smelting, continuous casting, blank heating, controlled rolling, controlled cooling and stacking slow cooling. The thickness of the obtained steel plate is 50-100 mm, the yield strength is larger than or equal to 420 MPa, the impact energy at the temperature of-60 DEG C is larger than or equal to 200 J, the strength difference of the whole plate is smaller than or equal to 40 MPa, and the steel plate has high strength, high toughness, good weldability and high uniformity and meets the requirement for the deep and far sea extremely-low-temperature environment.

The invention relates to the technical field of extra-thick maritime work steel resistant to tropical marine climate corrosion, in particular to EH40 extra-thick maritime work steel resistant to tropical marine climate corrosion and a manufacturing method of the EH40 extra-thick maritime work steel resistant to tropical marine climate corrosion. The high-strength steel is composed of the following chemical components in percentage by weight: 0.065%-0.08% of C, 0.15%-0.3% of Si, 1.5%-1.7% of Mn, less than or equal to 0.02% of P, less than or equal to 0.01% of S, 0.015%-0.03% of Als, 0.4%-0.8% of Ni, 0.1%-0.2% of Cu, 0.1%-0.15% of Co, 0.05%-0.15% of Sn, 0.01%-0.03% of V, 0.01%-0.015% of Ti, 0.002%-0.004% of N and the balance of Fe and inevitable impurities. The thickness of the finished steel plate can reach 100 mm, and the corrosion resistance of the steel plate in the tropical marine climate environment is remarkably improved while EH40-grade high strength, high toughness and excellent weldability are kept.

The present invention discloses a thermoforming mold and equipment, which are applied to the field of thermoforming technology. The thermoforming mold includes: an upper mold and a lower mold, wherein a cavity for placing a workpiece is formed between the upper mold and the lower mold, and a cavity is provided inside each of the upper mold and the lower mold. In addition, a hollow portion is provided at a target position on one side of the upper mold and the lower mold near the cavity, and the hollow portion is connected to the cavity so that a medium in the cavity can be sprayed onto the workpiece through the hollow portion; a plurality of ejectors, wherein the ejectors are installed in the cavity of the upper mold and / or the lower mold; and a plurality of medium pipelines, which are arranged in the cavity and are used to supply medium to the ejectors, and the pressure of the medium pipelines is adjustable. The thermoforming mold provided by the present invention can improve the forming accuracy and efficiency of the workpiece, effectively eliminate the phenomenon of workpiece quenching deformation, and the weldability of the workpiece after quenching is good, and the workpiece surface is not easily oxidized.

The invention discloses a wear-resistant alloy composition and application. The wear-resistant alloy composition comprises 0.9 wt% to 2.65 wt% of C, 0.58 wt% to 1.35 wt% of Si, 0.31 wt% to 0.45 wt% of Mn, 6.5 wt% to 11.35 wt% of Cr, 0.25 wt% to 1.25 wt% of Mo, 7.15 wt% to 12.65 wt% of V and the balance Fe and inevitable impurities. Powder metallurgy is not needed, direct forming can be achieved through 3D printing, the heat treatment requirement is lower, operation is easy, a harsh heat treatment process is not needed, the obtained alloy has HRC63 or higher hardness, and the average friction coefficient at the normal temperature is only about 0.37. Moreover, the wear-resistant alloy composition is good in welding performance, and the problem that interlayer cracking occurs in the 3D printing or welding process or after the high-C-content alloy is solved.

The invention discloses a manufacturing method of a tantalum alloy T-shaped welding joint, and relates to the technical field of non-ferrous metal welding. The method comprises the steps that a tantalum alloy material is obtained, the performance and weldability are analyzed to determine a welding scheme, and a groove form and a gas protection device are designed; welding process parameters are optimized, and a gas protection device is adopted to complete welding; carrying out visual, macroscopic and microscopic detection on the welding seam to obtain a detection result; the method further comprises the steps of selecting matched welding wires, determining single-face V-shaped groove parameters, designing a gas protection device structure, optimizing welding current, treating a welding site and a material surface and the like. Compared with the prior art, the method can ensure the welding quality, maintain the material performance, realize high-precision welding, comprehensively evaluate the welding seam quality and improve the product reliability and safety.

The invention discloses high-performance bridge steel and a production method thereof, and belongs to the technical field of ferrous metallurgy. The bridge steel comprises the following chemical components in percentage by mass: 0.09%-0.11% of carbon; silicon: less than or equal to 0.55%; 1.4%-1.6% of manganese; less than or equal to 0.018% of phosphorus; sulfur: < = 0.005%; 0.15% to 0.20% of niobium; less than or equal to 0.08% of vanadium; 0.006% to 0.03% of titanium; 0.01 to 0.02 percent of chromium; 0.01% or less of nickel; less than or equal to 0.3% of copper; 0.01% to 0.045% of aluminum; less than or equal to 0.3% of molybdenum; not more than 0.008% of nitrogen; and the balance of iron and inevitable impurities. According to the high-performance bridge steel and the production method thereof, by optimizing the component design and the production process, production of the bridge steel with high strength, low yield ratio, high toughness and good welding performance can be achieved.

The invention discloses a production method of high-toughness NM450 wear-resistant steel. The steel comprises the following chemical components in percentage by weight: 0.19%-0.20% of C, 0.25%-0.45% of Si, 1.10%-1.20% of Mn, less than or equal to 0.010% of P, less than or equal to 0.002% of S, 0.65%-0.70% of Cr, 0.020%-0.025% of Nb, 0.014%-0.020% of Ti, 0.070%-0.090% of Alt, 0.0014%-0.0020% of B, less than or equal to 0.00015% of H, less than or equal to 0.0045% of N, less than or equal to 0.0015% of O and the balance of Fe and inevitable impurities. The process comprises the steps of converter smelting, LF refining, VD vacuum degassing, continuous casting, heating, rolling and heat treatment, the thickness of the produced NM450 wear-resistant steel plate ranges from 6 mm to 25 mm, the surface hardness ranges from 420 HBW to 480 HBW, the yield strength is larger than or equal to 1200 MPa, the tensile strength is larger than or equal to 1400 MPa, the elongation is larger than or equal to 14%, the requirement for 6a diameter 90-degree cold bending is met, the impact Akv at the temperature of-20 DEG C is larger than or equal to 60 J, the impact Akv at the temperature of-40 DEG C is larger than or equal to 40 J, the toughness performance is matched, the bending cold forming performance is excellent, and the welding performance is good.

The invention relates to the technical field of electronic packaging and welding, and particularly discloses Ag-Cu-Ti-based composite brazing filler metal and a preparation method and application thereof. The composite material comprises the following components in percentage by weight: 87%-96.5% of Ag-Cu28 alloy powder, 3%-8% of TiH2 and 0.5%-5% of a reinforcing phase, and the reinforcing phase is Ag-coated titanide or ceramic particles. According to the method, the comprehensive welding performance of the brazing filler metal is improved by adopting a method of coating the reinforcing phase with Ag, and meanwhile, the negative influence caused by adding the reinforcing phase is overcome. Aggregation of reinforced phase particles can be reduced through Ag coating, uniform distribution of the reinforced phase fine particles in the brazing filler metal is achieved, and generation of large brittle phases is greatly reduced. And meanwhile, the fluidity of the brazing filler metal is enhanced, the joint filling capacity of the brazing filler metal is improved, and the welding voidage of a connector is effectively reduced. In addition, the Ag coating can avoid the reaction between the reinforcing phase and the Ti element, and the influence of the reinforcing phase on the melting point of the brazing filler metal is reduced.

The invention discloses a method for improving the welding performance of low-alloy high-strength wind power steel, which is characterized by comprising the steps of optimization of welding heat input, preheating before welding, welding process control and slow cooling after welding. By optimizing the welding heat input parameters, reasonably controlling the time (t8 / 5) for cooling to 500 DEG C from 800 DEG C, adjusting the structure transformation behavior of the welding heat affected zone and combining the process measures of preheating before welding, slow cooling after welding and the like, precise regulation and control of the microstructure of the welding heat affected zone are achieved, the hardening tendency and the embrittlement phenomenon of a coarse grain zone are effectively restrained, and the welding quality is improved. And therefore, the strength, toughness and crack resistance of a welding joint are remarkably improved, and the high requirements of offshore wind power structural parts for welding quality and service performance are met.