601 results about "Weldability" patented technology

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 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.

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 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 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.

The invention discloses a production method of anti-acid pipeline steel X70MS. The technological process comprises converter smelting, refining, continuous casting, heating rolling, cooling and inspection warehousing, the produced anti-acid pipeline steel has high strength, good toughness, excellent low-temperature toughness, excellent HIC and SSCC resistance and excellent machining performance and welding performance, the yield strength of the steel is 485-560 Mpa, the tensile strength is 580-680 Mpa, the yield ratio is smaller than or equal to 0.88, and the yield ratio is smaller than or equal to 0.88. The plate thickness low-temperature impact toughness Akv is greater than or equal to 230J, the crack-arrest drop hammer temperature is-30 DEG C, the toughness area is greater than or equal to 88%, and the HIC resistance CLR is less than or equal to 5%, CTR is less than or equal to 1%, and CSR is less than or equal to 1%. And the 90% yield strength load SSCC is qualified.

The invention discloses a 420MPa-grade steel strip for a high-corrosion-resistance photovoltaic support based on Ti microalloying and low-aluminum high-magnesium coating synergistic reinforcement and a preparation method of the 420MPa-grade steel strip, and relates to the technical field of metal materials. Aiming at the requirements of a distributed photovoltaic bracket, a microalloy component taking a Ti element as a core is designed, and the microalloy component is matched with a low-aluminum high-magnesium micro-titanium coating system to prepare the 420MPa-grade steel belt for the high-corrosion-resistance photovoltaic bracket, which is based on Ti microalloying and low-aluminum high-magnesium coating synergistic reinforcement and has balanced performance and good corrosion resistance. And meanwhile, controlled rolling and controlled cooling and low-temperature annealing are adopted in the preparation process, so that the problem of poor formability of traditional steel is solved, energy consumption is reduced by utilizing a low-temperature rapid plating process, and the production efficiency is improved. While the alloy cost is reduced, balanced optimization of strength-corrosion resistance-forming-welding performance is achieved, and low cost and greenization of a photovoltaic support material are promoted.

The invention discloses a rolling process method for Q355C, D and E grade steel plates with the thickness of 100-150 mm. The rolling process method comprises the following steps that raw materials are prepared and smelted; the molten steel is transferred into an LF furnace for refining, lime and fluorite slagging materials are added, the refined molten steel is transferred into a VD furnace for vacuum degassing treatment, and the vacuum degree is smaller than or equal to 67 Pa; continuous casting: carrying out continuous casting or die casting on the molten steel subjected to vacuum degassing for pouring, and controlling the pouring temperature to be 1550-1560 DEG C; heating: feeding the casting blank into a heat accumulating type heating furnace for heating, and controlling the heating temperature to be 1200-1240 DEG C; the heated casting blank is subjected to normalizing rolling, and in the rolling process, high-pressure water is used for reducing the surface temperature of the steel blank; cooling, wherein the rolled steel plate is subjected to accelerated cooling, and the water entering temperature is 890-910 DEG C; and stack cooling is conducted, specifically, the rolled steel plate is subjected to stack cooling, and the stack cooling temperature is higher than 420 DEG C. The Z-direction performance of the developed steel plate reaches Z35 through reasonable component design and the normalizing rolling and NCP technology, and the steel plate has good obdurability matching and welding performance.

The invention discloses a titanium alloy with high strength, high plasticity and toughness and a weldable structure. The titanium alloy is a Ti-Al-Mo-V-Cr-Zr series beta-rich type two-phase titanium alloy. According to the titanium alloy, the composition of the titanium alloy is controlled, the synergistic effect of high-strength contribution of Al and Mo, plasticity and toughness guarantee of V and Nb, structure optimization of Cr and Zr and low-oxygen cleanliness control is exerted, the multi-performance balanced type high-strength, high-plasticity and high-toughness weldable structure titanium alloy is obtained, and after heat treatment, the tensile strength Rm of the titanium alloy is larger than or equal to 1100 MPa, the ductility A of the titanium alloy is larger than or equal to 15%, the fracture toughness KIC of the titanium alloy is larger than or equal to 80 MPa.m < 1 / 2 >, and the impact toughness KV of the titanium alloy is larger than or equal to 40 J; and the welding seam strength matching coefficient is 0.9 or above, collaborative optimization of high strength, high plasticity and toughness, weldability and environmental adaptability is achieved, and therefore the structural mass is reduced, the service life is prolonged, integrated manufacturing is facilitated, and the high-strength and high-toughness alloy is suitable for key components in the industrial field and extreme working condition engineering scenes.

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

The invention relates to an easy-to-form corrosion-resistant and wear-resistant steel plate for a conveying pipeline and a manufacturing method thereof, and belongs to the field of pipeline steel. The surface Brinell hardness of the wear-resistant steel plate is 370-430 HB, the ductility is larger than or equal to 10%, the Charpy V-shaped impact energy at the temperature of-40 DEG C is larger than or equal to 30 J, d is equal to 4 t, and no crack exists after 180-degree cold bending; the martensite structure is uniform and fine, the grain size is larger than or equal to 7 grades, and the total grade of A, B, C and D fine inclusions in the structure is smaller than or equal to 2.0. And under the working condition that the pH value is 6.0-8.5, the corrosion resistance of the steel can be improved by 40% or above compared with that of Q355 structural steel. A high-cleanliness steelmaking continuous casting process, plate blank hydrogen diffusion, two-stage controlled rolling, high-temperature normalizing pretreatment, off-line quenching and tempering are adopted, control is conducted from the aspects of chemical component design, base metal structure and the like, and the low-temperature toughness, formability, corrosion resistance and weldability of the wear-resistant steel plate for the conveying pipeline are guaranteed; and a solution is provided for the application of the long-service-life wear-resistant pipeline.

The invention relates to high-toughness easy-to-weld carbon-free steel for ocean engineering and a preparation method, belongs to the technical field of steel smelting, and aims at solving at least one of the problems that the strength, toughness and welding performance of existing carbon-free steel cannot be considered at the same time, the production cost is low, the process is complex, and the production period is long. The invention relates to high-toughness easy-to-weld carbon-free steel for ocean engineering. The carbon-free steel comprises the following chemical components in percentage by mass: less than or equal to 0.01% of C, 0.10-0.35% of Nb, 0.05-0.15% of Mo and the balance of Fe and inevitable impurities. The strength bottleneck of carbon-free steel is broken through, and the balance of high strength and excellent toughness is achieved. Through the casting blank ultra-fast cooling and ferrite area rolling process and in combination with the Nb-Mo alloy design, the tensile strength is improved to 500 MPa or above, meanwhile, the impact energy at the temperature of-80 DEG C is larger than or equal to 200 J, and the problem that traditional steel depends on carbon element strengthening, and consequently obdurability matching is insufficient is solved.

The application belongs to the technical field of laser welding machines, and provides a wind-cooled heat dissipation mechanism for a laser welding machine and the laser welding machine, which comprises a first power assembly, a fan assembly and a second power assembly arranged in sequence along an air inlet airflow direction, further comprises a heat exchange cavity arranged between the fan assembly and the second power assembly, the heat exchange cavity comprises at least two heat dissipation flow channels extending in different directions, the air inlet airflow direction is substantially perpendicular to the air outlet airflow direction of an air outlet of the heat dissipation flow channel, the wind-cooled heat dissipation mechanism can simultaneously realize heat dissipation of two power modules by using the same fan assembly, the heat dissipation efficiency is high, the number of heat dissipation modules is saved, the overall volume is compact, the air supply mode is perpendicular, the air flow stroke is shortened, the problem of temperature concentration is solved, the heat dissipation efficiency is improved, the welding machine adopting the wind-cooled heat dissipation mechanism emits light more stably, and the welding performance is improved.

The object is to provide a Fe-Ni-Cr alloy for a sheathed heater jacket pipe which is excellent in oxidation resistance, corrosion resistance, and weldability, and which can be used in a humid high-temperature environment. The alloy for solving the object is a Fe-Ni-Cr alloy consisting of, in mass%, C: 0.001 to 0.050%, Si: 0.18 to 1.00%, Mn: 0.20 to 0.80%, P: 0.030% or less, S: 0.0001 to 0.0020%, Ni: 12 to 21%, Cr: 18 to 24%, Mo: 0.20 to 1.50%, Cu: 0.30% or less, Al: 0.10 to 0.70%, Ti: 0.10 to 0.70%, N: 0.002 to 0.015%, B: 0.0001 to 0.0010%, O: 0.0002 to 0.0030%, Ca: 0.002% or less, REM: 0.0010 to 0.0150% of one or two or more of La, Ce, and Y, and the balance of Fe and inevitable impurities, and satisfies formulae 1 and 2. 0.575 x Ni + 1.25 x Cr + 3.43 x Mo - 39 x P - 5.3 x Al - 64 1 x REM - 1018 x O ≥ 20.0 … (Formula 1). 1.5 x Mn + 41.3 x Si + 1469 x S - 1.67 x Al - 1.34 x Ti - 150 x O - 620 x REM ≥ 5.0 … (Formula 2).

The present application relates to a kind of weld reinforcement structure for stainless steel tank, belong to aerospace vehicle propellant tank structure technical field;First tank bottom, first short shell, barrel section, second short shell and second tank bottom;Wherein, first tank bottom and second tank bottom are hemispherical shell structure;First short shell, second short shell, barrel section are barrel section structure;First short shell, barrel section and second short shell are in turn horizontal coaxial butt joint;First tank bottom is coaxially installed at the axial outer end of first short shell;Second tank bottom is coaxially installed at the axial outer end of second short shell;The open end of first tank bottom is inserted into first short shell, and the outer wall of first tank bottom is butt joint with the inner wall of first short shell;The open end of second tank bottom is inserted into second short shell, and the outer wall of second tank bottom is butt joint with the inner wall of second short shell;The present application solves the problem that the welding performance of reinforcing material cannot be reinforced by partition thickness design, realizes the purposes such as high performance, low cost manufacturing of stainless steel tank.

This application provides a case, a battery, and an electric device. The case includes a bottom plate having a composite plate and a heat exchange plate. The composite plate is made of a first material portion and a second material portion, and includes a first welding surface formed from the first material portion. The heat exchange plate has a second welding surface made of a third material, where the third material is the same as the first material. The first and second welding surfaces are welded together. By using the composite plate instead of a conventional aluminum plate, the design improves weldability between the composite plate and the heat exchange plate, thereby reducing quality issues and improving manufacturing reliability of the case.

The present application relates to the technical field of steel material welding, and particularly relates to a welding method of Q690S high-strength steel for a hydropower station pressure pipeline. The present application comprehensively covers the welding joint form and thickness specification of the hydropower station pressure pipeline manufacturing and installation, solves the application problems of poor weldability of Q690S high-strength steel, low welding efficiency, difficult guarantee of welding joint performance, and easy generation of delayed cracks after welding, and the technical scheme is simple, has strong applicability, and the implementation effect meets the design technical conditions of large and super-large hydropower station pressure pipelines, and can be practically used for the welding manufacturing and welding installation in field environment of Q690S high-strength hydropower pressure pipeline.

This invention discloses a selective roughening method for ceramic copper-clad laminates, comprising the following preparation steps: S1 printing an active solder layer between ceramic and copper foil; S2 preparing the ceramic copper-clad laminate; S3 etching copper onto the sintered ceramic copper-clad laminate; S4 removing unwanted solder layers; S5 cleaning, roughening, cleaning, acid washing, cleaning, immersion, and drying the patterned ceramic copper-clad laminate according to the following process, and filling it with nano-silicon and organosilane; S6 printing a thermosetting wet film to expose the area to be surface treated; S7 removing the surface roughening structure; S8 finally, subjecting the ceramic copper-clad laminate to nickel plating, chemical silvering, and then stripping to form the final structure. Compared with the prior art, this invention has the following beneficial effects: effectively avoiding the problem of solder voids caused by surface roughening pits, good surface weldability, and the concave structure of the welding area effectively prevents solder overflow during the welding process and reduces micropores in the chemical silver plating layer.

The invention belongs to the technical field of chemical tin plating, and particularly relates to a micro-nano powder surface tin plating method which comprises the following steps: pretreating powder, adding main salt, a reducing agent, a coordination agent and an antioxidant into water, and stirring until the main salt, the reducing agent, the coordination agent and the antioxidant are completely dissolved; and the pretreated powder is added into the cylinder opening liquid to be subjected to a reaction, when the surface of the solution is subjected to the reaction, the supplementing liquid is added, stirring continues to be conducted till the reaction is completed, and the micro-nano powder with the tin-plated surface is obtained. According to the method for plating tin on the surface of the micro-nano powder, tin is plated on the surface of the micro-nano split body, so that the surface energy of the material can be effectively reduced, the material can be more easily infiltrated and combined with welding flux in the welding process, the welding performance of the material is remarkably improved, and the material is high in oxidation resistance, high in conductivity, high in dispersity and high in corrosion resistance. The whole process is simple, stable and suitable for large-scale production and application.

The application discloses a rare earth high-strength dual-phase steel and a forming method and application thereof, and belongs to the technical field of dual-phase steel. The forming method of the rare earth high-strength dual-phase steel comprises the following steps: converter smelting, LF refining, RH refining, adding cerium iron and yttrium iron at the end of the RH refining or before continuous casting, continuous casting, three-stage hot rolling, cold rolling and three-stage annealing. The rare earth high-strength dual-phase steel has good cold stamping formability, high weldability, no rare earth element segregation, no cracking of steel forming, high yield, and can be directly used to prepare automobile bodies after cold stamping forming at normal temperature. There is no rare earth inclusion or coarse carbon nitride brittle bulk agglomerate on the surface layer of the weld, the rare earth element is in a dispersed distribution state, has excellent dispersion strengthening effect, the weld is not prone to cracking, and the mechanical properties of the weld are superior to those of the base material.

The application discloses an aluminum nitride film circuit substrate and a preparation method thereof, and relates to the technical field of aluminum nitride substrates.The application is characterized by the following steps: a titanium film is plated on the surface of an aluminum nitride ceramic substrate by magnetron sputtering, and then a copper film is plated on the surface of the titanium film by magnetron sputtering; and a nickel film is plated on the surface of the copper film by a chemical plating method to prepare the aluminum nitride film circuit substrate.Through the titanium-copper gradient dynamic transition technology, a gradient alloy layer is formed to reduce the interface stress; the titanium and the surface of the aluminum nitride are combined through a chemical bond to form a dense transition layer, thereby relieving the difference in the thermal expansion coefficient; the copper enhances the conductive performance of the surface of the aluminum nitride ceramic substrate; the titanium compensates for the interface defects of the mismatch between the copper and the aluminum nitride ceramic lattice; the chemical nickel plating enhances the hardness and corrosion resistance of the aluminum nitride ceramic substrate, and the aluminum nitride film substrate is endowed with weldability and bondability.