1031 results about "Weldability" patented technology

The invention discloses a preparation method of preheating-welding-free extra-thick steel S355MLO for ocean engineering, and belongs to the technical field of metal materials. The steel comprises the following chemical components in percentage by mass: 0.04%-0.06% of C, 0.15%-0.50% of Si, 1.35%-1.45% of Mn, less than or equal to 0.008% of P, less than or equal to 0.003% of S, 0.012%-0.02% of Ti, less than or equal to 0.015% of Al, 0.15%-0.25% of Ni, less than or equal to 0.18% of Cu, less than or equal to 0.18% of Cr, less than or equal to 0.35% of Ceq = [C + Mn / 6 + (Cr + Mo + V) / 5 + (Ni + Cu) / 15] and the balance of Fe and inevitable impurities. The low-carbon and high-manganese component design is adopted, the S355MLO super-thick steel plate with the maximum thickness of 100 mm is produced through a continuous casting billet, the carbon equivalent Ceq is smaller than or equal to 0.35, and high strength, high toughness and high welding performance are integrated. The base metal and welding toughness of the thick steel plate produced by the TMCP process are improved through the component and inclusion regulation and control technology, the process is simple, the production cost is low, the production efficiency is high, preheating before welding can be avoided, and energy conservation and consumption reduction are achieved.

The invention discloses a production method of 420-grade preheating-free welding maritime work steel, and belongs to the technical field of metal materials. The steel comprises the following chemical components in percentage by mass: 0.04%-0.06% of C, 0.15%-0.50% of Si, 1.45%-1.55% of Mn, less than or equal to 0.008% of P, less than or equal to 0.003% of S, 0.012%-0.02% of Ti, less than or equal to 0.010% of Al, 0.15%-0.25% of Ni, 0.10%-0.18% of Cu, 0.10%-0.18% of Cr, less than or equal to 0.38% of Ceq = [C + Mn / 6 + (Cr + Mo + V) / 5 + (Ni + Cu) / 15], and the balance of Fe and inevitable impurities. A low-carbon and high-manganese component design is adopted, the S420MLO super-thick steel plate with the maximum thickness capable of reaching 100 mm is produced through a continuous casting billet, the carbon equivalent Ceq is smaller than or equal to 0.38, and high strength, high toughness and high welding performance are integrated. The base metal and welding toughness of the thick steel plate produced by the TMCP process are improved through the component and inclusion regulation and control technology, the process is simple, the production cost is low, the production efficiency is high, preheating before welding can be avoided, energy is saved, consumption is reduced, and the method is environmentally friendly.

The invention discloses a metal material welding performance testing device and testing method, and belongs to the technical field of welding testing devices. The metal material welding performance testing device is characterized by comprising a workbench, a fixed clamp is arranged at one end of the workbench, a movable clamp is arranged at the other end of the workbench, and a loading mechanism is arranged between the fixed clamp and the movable clamp; the fixed clamp comprises a fixed seat, the movable clamp comprises a movable seat, and a power structure for driving the movable seat to slide on the supporting table is arranged on the supporting table; clamping mechanisms for clamping a workpiece are arranged on the fixed seat and the movable seat, a vibration structure for applying vibration to the workpiece is arranged in the center of the clamping mechanism on the fixed seat, and the vibration structure is located in the workpiece. By adopting the device and the method for testing the welding performance of the metal material, disclosed by the invention, the problem that an existing testing device cannot be used for testing the tensile property and the compressive property of a welded suspension arm under the condition of multi-load loading can be solved.

The invention discloses 460-grade preheating-free welding maritime work steel and a preparation method thereof, and belongs to the technical field of metal materials. The steel comprises the following chemical components in percentage by mass: 0.04 to 0.06 percent of C, 0.15 to 0.50 percent of Si, 1.75 to 1.85 percent of Mn, less than or equal to 0.008 percent of P, less than or equal to 0.003 percent of S, 0.012 to 0.02 percent of Ti, less than or equal to 0.015 percent of Al, 0.25 to 0.35 percent of Ni, 0.20 to 0.28 percent of Cu, 0.20 to 0.25 percent of Cr and the balance of Fe and inevitable impurities. A low-carbon and high-manganese component design is adopted, the S460MLO super-thick steel plate with the maximum thickness capable of reaching 100 mm is produced through a continuous casting billet, the carbon equivalent Ceq is smaller than or equal to 0.45, and high strength, high toughness and high welding performance are integrated. The base metal and welding toughness of the thick steel plate produced by the TMCP process are improved through the component and inclusion regulation and control technology, the process is simple, the production cost is low, the production efficiency is high, preheating before welding can be avoided, energy is saved, consumption is reduced, and the method is environmentally friendly.

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 discloses a recovery method of titanium alloy powder for additive manufacturing, and relates to the technical field of titanium alloy materials, the recovery method comprises the following steps: step 1, sheath material selection and processing: carbon steel with good welding performance is preferably selected as a sheath material; the size of the sheath is designed according to the actual ingot shape condition; 2, selecting raw materials, namely mixing titanium alloy spherical powder and micron-sized titanium alloy powder with the granularity of 15-300 mu m and the same brand, and performing an HIP + VAR process to obtain a titanium alloy cast ingot with more uniform material components and smaller element content range; a conventional titanium alloy powder hot isostatic pressing process needs a high treatment temperature which is generally between 930 DEG C and 1050 DEG C, the density of a blank after hot pressing is required to be close to 100%, according to the method, the material hot isostatic pressing treatment temperature is required to be 600 DEG C to 650 DEG C, an electrode blank with certain strength meeting VAR smelting can be obtained, energy consumption is reduced, and meanwhile the requirement for the performance of hot isostatic pressing equipment is extremely low.

The invention discloses a production method of a 500MPa-grade galvanized dual-phase steel strip for an automobile bracket. The 500MPa-grade galvanized dual-phase steel strip comprises the following chemical components in percentage by mass: 0.05-0.08% of C, less than or equal to 0.25% of S , 1.5-1.8% of Mn, less than or equal to 0.020% of P, less than or equal to 0.015% of S, 0.015-0.060% of Alt, 0.01-0.25% of Cr, 0.0010-0.0030% of Ca and the balance of Fe. The production method specifically comprises the following steps: a smelting-continuous casting production process flow; a hot rolling production technological process; pickling and cold rolling; and carrying out continuous hot galvanizing and finishing processes. The 500MPa-grade galvanized dual-phase steel for the automobile bracket has the characteristics of low yield ratio, high work hardening capacity, good corrosion resistance, welding performance, no yield elongation, no room-temperature aging, high elongation and the like, and can meet the requirements of users on light-weight and high-corrosion-resistance material selection.

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 discloses a 1000MPa-grade steel plate with high toughness, strain aging embrittlement resistance and excellent weldability and a manufacturing method thereof. The 1000MPa-grade steel plate comprises the following components in percentage by weight: 0.09 to 0.13 percent of C, less than or equal to 0.20 percent of Si, 0.70 to 1.00 percent of Mn, less than or equal to 0.013 percent of P, less than or equal to 0.0030 percent of S, 0.15 to 0.40 percent of Cu, 1.50 to 3.00 percent of Ni, 0.45 to 0.70 percent of Cr, 0.40 to 0.65 percent of Mo, 0.040 to 0.070 percent of V, 0.010 to 0.030 percent of Nb, 0.004 to 0.012 percent of Ti, 0.040 to 0.070 percent of Als, 0.0009 to 0.0017 percent of B, less than or equal to 0.0050 percent of N, less than or equal to 0.0030 percent The tensile strength of the steel plate is larger than or equal to 950 MPa, the yield strength is larger than or equal to 890 MPa, the Charpy longitudinal / transverse impact energy (single value) at the temperature of-60 DEG C is larger than or equal to 100 J, the strain aging transverse impact energy (single value) at the temperature of-40 DEG C is larger than or equal to 47 J, the elongation at break delta 5 is larger than or equal to 15%, and the weldability is good (the preheating temperature is smaller than or equal to 150 DEG C, and the steel plate can bear welding heat input of 30 kJ / cm-50 kJ / cm). And the method is particularly suitable for hydropower engineering, ocean platform structures and major equipment manufacturing.

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 rare earth-containing 500HB-grade high-toughness wear-resistant steel plate, which is characterized by comprising the following chemical components in percentage by mass: 0.24 to 0.28 percent of C, 0.15 to 0.25 percent of Si, 0.30 to 0.55 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.0015 percent of S, 0.90 to 1.10 percent of Cr, 0.05 to 0.70 percent of Mo, 0.05 to 0.25 percent of Ni, 0.002 to 0.005 percent of Ti, 0.055 to 0.065 percent of Nb, 0.010 to 0.020 percent of V, 0.0005 to 0.0010 percent of B, 0.070 to 0.085 percent of Alt, less than or equal to 0.0050 percent of N, less than or equal to 0.0003 percent of H, less than or equal to 0.60 percent of Ceq, more than or equal to 80ppm of rare earth Ce and compared with conventional wear-resistant steel, the corrosion resistance is improved by 20%.

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 halogen-free low-splashing environment-friendly solder wire and a preparation method thereof, and relates to the technical field of electronic welding materials, and the halogen-free low-splashing environment-friendly solder wire is prepared from the following raw materials in percentage by mass: 1-4wt% of halogen-free scaling powder and the balance of lead-free solder; the lead-free solder is composed of the following components of Cu, Bi, Al, Ga, Ir, Ca, In and Sn. The halogen-free scaling powder comprises the following components: (3, 6-diamino acridine-9-yl) boric acid, glycerol triabietate, 3-(N-morpholinyl)-2-hydroxy propanesulfonic acid sodium salt, 3-trihydroxymethyl methylamino-2-hydroxy propanesulfonic acid, hexahydro-1, 3-ethoxy-s-triazine, a functional copolymer, a surface active agent, a corrosion inhibitor, a halogen-free activity reinforcing agent, an antioxidant, a solvent and rosin resin. The solder wire is low in splashing rate, high in surface resistivity and welding spot reliability, free of obvious corrosivity and good in weldability.

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.

The invention discloses 780MPa-grade hot-dip galvanized DH steel and a manufacturing method thereof, the alloy components of DH780 steel grade are optimized, the contents of Si and Mn elements are reduced, and the generation of external oxides is reduced, so that the risk of plating leakage defects is reduced; besides, by improving the dew point in the annealing process and increasing the oxygen partial pressure in the annealing atmosphere, internal oxidation of Si and Mn elements on the surface layer of the DH780 steel grade is promoted, so that the plating leakage defect is effectively reduced, and the surface quality of the steel plate is remarkably improved; according to the method, the production cost is reduced, the weldability and machinability of a product are improved, the integrity and uniformity of a plating layer are effectively improved, the corrosion resistance of the product is improved, the service life of the product is prolonged, and the application range of the DH780 steel grade hot-dip galvanized steel plate is widened.

The utility model relates to a PE (Poly Ethylene) water supply reinforced pipe which comprises an inner layer, a middle layer and an outer layer, the inner layer and the outer layer are made of high-density polyethylene resin, the middle layer is a hole net pipe steel framework, and the hole net pipe steel framework is adhered with the high-density polyethylene resin of the inner layer and the outer layer through hot melt adhesive. According to the PE water supply reinforced pipe, the steel-plastic composite technology is adopted, the PE plastic pipe is improved from the product structure, the problem that the wall thickness is not uniform is solved, and nearly half of raw materials are saved. The product has high compressive strength and creep resistance, good ring stiffness and impact resistance, low linear expansion coefficient and heat conductivity coefficient, good weldability, environmental stress cracking resistance and rapid cracking resistance, and is convenient to construct, simple in welding process and low in engineering comprehensive cost.

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 discloses a medium-strength high-plasticity Ti-Ta alloy resistant to boiling concentrated nitric acid corrosion. The medium-strength high-plasticity Ti-Ta alloy is composed of, by mass, 5.5%-6.5% of Ta, 0.16%-0.6% of O and the balance Ti and inevitable impurities. In addition, the invention further discloses a preparation method of the Ti-Ta alloy, sponge titanium, Ti-Ta intermediate alloy scraps and titanium dioxide powder wrapping titanium foil are mixed and then smelted, and a mixture is obtained; and then rolling and annealing to obtain the Ti-Ta alloy. The alpha-type titanium alloy with a uniform structure and a single phase is obtained through oxygen microalloying, so that the alloy has excellent mechanical properties and nitric acid corrosion resistance and also has excellent welding performance and machinability, the alloy is simple in component, the preparation method is short in period and high in efficiency, the strong plasticity and the nitric acid corrosion resistance are synergistically improved, and the preparation method is suitable for industrial production. Basic data support and candidate materials are provided for reinforcement and corrosion prevention of metal structure materials for spent fuel aftertreatment equipment and design of new materials.

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 discloses a flux-cored wire with high crack resistance and wear resistance and a preparation method of the flux-cored wire. The flux-cored wire comprises the following flux-cored raw materials in percentage by mass: 6-10% of electrolytic manganese; 28 to 34% of metal chromium; 0.5 to 1.5 percent of ferrotitanium; 1-4% of tungsten powder; 5-9% of nickel powder; 4-8% of 45 # ferrosilicon; 8 to 12% of colloidal graphene; 8-12% of molybdenum powder; and the balance of iron powder. According to the flux-cored wire, C, W, Cr, Mo and other elements are added into the flux core, the proportion of flux core powder is reasonably adjusted, and the flux-cored wire is suitable for surfacing continuous casting rollers, hot rolling rollers, shafts with the working temperature lower than 510 DEG C and sealing faces of medium-temperature and high-pressure stop valves and has the advantages of being high in heap melting speed, good in weldability, high in surface abrasion resistance, low in cost and the like. The hardness value of the steel plate can basically reach 50 HRC, and the steel plate has good crack resistance.

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.