43results about How to "Avoid severe oxidation" patented technology

A system for pumping molten metal and melting metal scrap in a furnace that includes a first well that is separated from a second well by a refractory separating wall. The first well and the second well are in fluid communication with a main vessel, the separating wall including a passageway for molten metal. The system includes a pump disposed in the first well for pumping molten metal. A scrap charging vessel is disposed in the second well into which the scrap is added to molten metal contained therein. A conduit extends from the pump over the separating wall. Molten metal pumped from the pump travels from the conduit into the scrap charging vessel.

The invention discloses a positive temperature coefficient (PTC) thermal resistance alloy wire and a preparation method thereof. The alloy wire comprises the chemical ingredients by weight percent of 45-82.0% of nickel, 0.1-0.6% of silicon, 0.22-0.35% of manganese, 0.02-0.04% of yttrium, 0.04-0.06% of misch metal, 0.05% or less of carbon, 0.01% or less of sulphur, 0.001% or less of phosphorus and the balance of iron. The mean resistance temperature coefficient at 0-150 DEG C is 2500*10(-6) per DEG C to 5000*10(-6) per DEG C by changing the matching content of the components; the PTC thermal resistance alloy wire of which the resistance temperature coefficient which is urgently needed at present and higher than 3000*10(-6) per DEG C is included; the highest mean resistance temperature coefficient can be 5000*10(-6) per DEG C, and the requirements of more sensitive temperature control of novel electrical equipment can be met.

The invention discloses a manufacturing method of a PCB large copper surface character. The method comprises the following steps: preparing a solder mask layer on a production board, and then, carrying out first pickling treatment on the production board; performing silk-screen printing of first surface character ink on the copper surface of one surface of the production board, and pre-curing thefirst surface character ink through pre-baking; carrying out second pickling treatment on the production plate; and performing silk-screen printing of second surface character ink on the copper surface of the other surface of the production board, and thoroughly curing the first surface character ink and the second surface character ink through baking. According to the method, the character manufacturing process is optimized, and before characters are manufactured on the large copper surface, the pickling process is added, so that the copper surface oxide layer obtained after high-temperatureboard baking is removed, the copper surface roughness is increased, the combination area of the copper surface and character ink is increased, and the problem of character dropping of the large coppersurface is solved.

The invention discloses an extrusion method of a BMn40-1.5 manganese copper-nickel alloy tube. The method comprises steps as follows: step one, preparation of blanks; step two, primary induction heating; step three, glass powder lubrication; step four, chambering; step five, secondary induction heating; step six, secondary glass powder lubrication; step seven, extrusion forming, wherein the blanks subjected to glass powder lubrication enters an extruder for extrusion forming. By means of the extrusion method of the BMn40-1.5 manganese copper-nickel alloy tube, severe oxidation in the heating process is effectively avoided, adverse factors hindering deformation of the material are avoided, forming of heat cracks in the material forming process is reduced, and the surface quality of a prepared seamless tube is improved. The performance and the size of the seamless BMn40-1.5 manganese copper-nickel alloy tube produced with the method can meet the requirements of a user.

The invention discloses a Zn-Al-Mg-RE zinc ingot preparation method which comprises the following steps: preparing a Zn-Al-Mg-RE ternary intermediate alloy; adding pure Mg in a zinc tank, and dissolving the pure Mg completely; then adding the prepared Zn-Al-RE ternary intermediate alloy in the zinc tank containing the pure Mg, and standing until the Zn-Al-RE ternary intermediate alloy is dissolved completely; and finally pouring a Zn-Al-Mg-RE zinc ingot in a finished product mold. A Zn-Al-Mg-RE quaternary alloy zinc ingot is prepared with low cost rapidly and conveniently by adopting the preparation method, and the yields of Mg and RE elements are improved greatly.

The first purpose of the invention is to provide a forging and pressing method of steel rail heel; a steel rail heel comprises a pre-forging heel and a final forging heel; the pre-forging heel comprises a first section, a second section, and a third section; the final forging heel comprises a fourth section and a fifth section; the method specifically comprises the following steps: implementing a first stage forging and pressing after heating the first section, the second section and the third section, wherein the first two sections are molded by forging and pressing, the third section is pre-deformed; and implementing a second stage forging and pressing after heating the last three sections. The provided forging and pressing method adopts a measure of molding twice, thereby being able to solve the defect that the size of the molded final forging heel is unqualified, as well as greatly reducing the molding force in the entire steel rail heel product molding process. The second purpose of the invention is to provide a three-position molding die with a simple integral structure; a second upper die section inside a pre-forging rail molding cavity and a first pre-forging insert inside a final forging molding cavity are both in detachable structures, thereby meeting different requirements to the three-position molding die in the twice forging and pressing process; the three-position molding die is convenient to be assembled, and strong in practicability.

The invention discloses a power battery cover plate. The power battery cover plate comprises a top cover, a positive pole and a negative pole. The positive pole is an aluminum pole. The positive poleis connected to the top cover through a positive injection molding part or riveted to the top cover through a positive pressing block. The negative pole comprises an aluminum part and a copper part, one part of the aluminum part penetrates out of the upper side wall of the top cover, the copper part is located on the lower portion of the top cover, and the negative pole is connected to the top cover through a negative injection molding part or riveted to the top cover through a negative pressing block. According to the power battery cover plate, the part, exposed out of the top cover, of the negative pole column is prevented from being seriously oxidized, the service life of the negative pole column and the whole power battery cover plate is prolonged, the connecting structure between thepole column and the top cover is simplified, the positive pole column and the negative pole column are convenient to install, and the mass of the whole power battery cover plate is reduced.

The invention discloses a method for rapidly preparing a manganese-cobalt spinel coating through microwave mixed heating, relates to the technical field of microwave processing and metal surface modification, and aims at solving the problems that components are uncontrollable, the preparation process is tedious, base metal is seriously oxidized and the like when the manganese-cobalt spinel coating is prepared through a traditional technology. The method for preparing the manganese-cobalt spinel coating comprises the following steps: 1, weighing Co powder, MnO2 powder and sintering aid powder as raw materials; 2, placing the raw materials in a ball-milling tank for wet ball-milling treatment; 3, carrying out surface treatment on the ferritic stainless steel; 4, evenly smearing the mixed powder on the surface of the ferritic stainless steel, and performing compression molding; and 5, imbedding the stainless steel attached with the prepressing coating in the high-microwave-absorptivity powder in the microwave sintering furnace, and performing sintering and heat preservation in the air atmosphere. The manganese-cobalt spinel protective layer is prepared by adopting a microwave mixed heating method, the heating rate is high, the heating efficiency is high, the sintering temperature is greatly reduced, the sintering time is shortened, overall uniform heating is realized, and the internal stress of the coating is small.

The invention relates to the technical field of titanium alloy seamless tubes and discloses a production process of a hot-rolled large-caliber thin-wall titanium alloy seamless tube. The technologicaloperation process of the production process mainly comprises the following steps of A, an operator removes impurities in a titanium alloy material through a clogging screen; B, manufacturing the impurity removed titanium alloy material into a titanium alloy blank; C, pouring the titanium alloy blank into a seamless tube mold; D, just placing the titanium alloy seamless tube mold into an annular furnace to be heated; E, grabbing the heated titanium alloy blank seamless tube into a cooling device through a conveying device; F, conducting demolding after titanium alloy ingredients are subjectedto heating and cooling to generate a solid titanium alloy cylinder; and G, conducting fixing on the solid titanium alloy cylinder through a machining lathe. Through the production process of the hot-rolled large-caliber thin-wall titanium alloy seamless tube, the problems that titanium has a reaction with carbon, hydrogen, nitrogen and oxygen at high temperature, the organization structure of thetitanium is changed, the physical and chemical characteristics of the titanium are affected and the using requirements can be hardly met are solved.

The invention discloses welding equipment with a smearing mechanism for exhaust pipes of upper shells of air-conditioning compressors. The welding equipment comprise a bearing pond and controllers. Abase, a nitrogen supply device and a worktable are sequentially arranged in the bearing pond from bottom to top, a plurality of base plates are arranged on the worktable, clearing stations, smearing stations and welding stations are arranged on the bearing pond, a support plate is arranged at the end, which is close to the clearing stations, of the bearing pond, a clearing mechanism and a dust collection mechanism are arranged on the support plate, the smearing mechanism is arranged on the side, which is close to the smearing stations, of the bearing pond, a welding mechanism is arranged on the side, which is close to the welding stations, of the bearing pond, gas outlet assemblies are arranged on the base plates and are connected with the nitrogen supply device by nitrogen delivery pipes,nitrogen electromagnetic valves are arranged between the nitrogen supply device and the nitrogen delivery pipes, and stepper motors, the nitrogen electromagnetic valves, the nitrogen supply device, the clearing mechanism, the smearing mechanism and the welding mechanism are electrically connected with the controllers. The welding equipment has the advantages that that welding paste can be automatically smeared by the welding equipment, accordingly, the smearing efficiency can be improved, and the brightness of the exhaust pipes and the upper shells can be guaranteed.

The invention discloses a PTC thermistor alloy wire with a high resistance temperature coefficient and a preparation method of the PTC thermistor alloy wire. The PTC thermistor alloy wire comprises the following chemical components in percentage by mass: 78%-82% of nickel, 0.28%-0.60% of silicon, 0.30%-0.35% of manganese, 0.02%-0.04% of yttrium, 0.04%-0.06% of misch metal, not more than 0.05% of carbon, not more than 0.01% of sulphur, not more than 0.001% of phosphorus and the balance of iron; the mean resistance temperature coefficient of the alloy wire at 0-150 DEG C is 4800*10<-6> DEG C to 5,000*10<-6> DEG C; and the specific resistance of the alloy wire is (0.17-0.19)+/-0.02muohm.m. The alloy wire disclosed by the invention is currently needed alloy wire with a relatively high resistance temperature coefficient; and the mean resistance temperature coefficient can be up to 5,000*10<-6> DEG C, and meets relatively sensitive temperature control requirements of emerging electric equipment.

The invention discloses a synthesis method of a porous black phosphorus nanosheet for an ion battery negative electrode material, and belongs to the technical field of synthesis of nano materials. The invention aims to solve the problems that the synthesis conditions of the existing black phosphorus material are harsh, the two-dimensional black phosphorus nanosheet needs complex ultrasonic stripping, the construction method of the porous black phosphorus nanosheet is complex, and the pore diameter is too large. The preparation method comprises the following steps: 1, carrying out ball milling on phosphorus trichloride, anhydrous zinc chloride and metal sodium to obtain a ball-milled mixture; 2, carrying out cleaning, centrifugal separation and vacuum drying on the ball-milled mixture to obtain the porous black phosphorus nanosheet. The method is used for synthesizing the porous black phosphorus nanosheet of the negative electrode material of the ion battery.

The invention belongs to the technical field of metal welding, and particularly relates to a copper and steel bimetal bridging welding method. The method includes firstly adding copper material and charcoal into a steel drum, then placing the steel drum in a heating furnace to form flux inside, placing the steel drum with the flux into a centrifuge, turning on the centrifuge to rotate in the speed of 400 to 800 rpm, allowing the flux to cool till solidifying as copper alloy, allowing the middle of the copper alloy to form a sump, obtaining a bimetal drum, then placing the bimetal drum into casting sand to cool till room temperature, obtaining a bimetal combined drum, rolling, extruding, tensioning, forging and cutting the bimetal combined drum, obtaining a steel and copper welding bridge, welding steel to be welded to the steel side of the welding bridge, welding copper to be welded to the copper side of the welding bridge, and finishing steel and copper welding. According to the technical scheme, the atomically-bound copper and steel bimetal serves as a bridge, copper and copper, steel and steel can be welded easily, and copper and steel bimetal welding can be realized.

The invention belongs to the field of magnetic materials, and discloses an oxygen partial pressure control sintering method for preparing manganese zinc ferrite through a re-grinding material. The method comprises the following steps: heating a manganese zinc ferrite re-grinding material compacted blank obtained through pretreatment at room temperature to 900 DEG C; feeding nitrogen for replacement when the temperature is risen to 900 DEG C, adjusting the oxygen partial pressure to be 0.5 to 15 percent, stopping feeding the nitrogen, continuously rising the temperature to sintering temperatureto perform thermal insulation sintering, keeping the obtained oxygen partial pressure till a thermal insulation sintering stage is stopped, and sealing a sintering cavity at the thermal insulation sintering stage; finally performing cooling in a flowing nitrogen condition, so as to obtain a sintering product. The method has the advantages that nitrogen is not required to be continuously fed at asecond temperature rising stage and the thermal insulation sintering stage, the dosage of nitrogen required during sintering is greatly saved, the preparation cost is reduced, and the obtained soft magnetic property is obviously better than that of the manganese zinc ferrite prepared through a common sintering method through the control of the sintering oxygen partial pressure.

The invention discloses an Al-Mg alloy welding wire and a preparation method thereof. The Al-Mg alloy welding wire comprises the following components in percentage by weight: 4.0%-4.5% of Mg, 1.2%-2.0% of Zn, 0.1%-0.15% of Cr, 0.1%-0.25% of Mn, 0.2%-0.4% of Si, 0.10%-0.15% of Ti, 0.05%-0.2% of Sc, 0.05%-0.2% of Zr, 0.05%-1.5% of late transition metal and the balance of aluminum. The Al-Mg alloy welding wire of some examples is low in melting point and good in base metal wettability, the strength can reach 423 Mpa, the ductility can reach 13.3%, the mechanical property is excellent, and meanwhile the Al-Mg alloy welding wire further has excellent corrosion resistance. The method can be used for welding various high-strength aluminum alloys, pseudo soldering, insufficient soldering and hot cracks of weldments are effectively avoided, and the comprehensive mechanical property of a welded joint is remarkably improved.

The invention discloses a low-cost and high-efficiency preparation method of a steel/magnesium laminar composite plate strip, and belongs to the technical field of metal laminar composite material preparation. The method comprises the following steps of firstly, softening and annealing steel and magnesium plate strip blanks, mechanically grinding the surfaces to be compounded of the steel and magnesium plate strip blanks, carrying out steel/magnesium laminated assembly, heating at 150 DEG C-300 DEG C, carrying out pre-rolling compounding to obtain a steel/magnesium pre-compounded plate strip, carrying out stress relief annealing, mechanically grinding the surfaces to be compounded of the steel/magnesium pre-compounded plate strip and the magnesium plate strip blank, carrying out (steel/magnesium)/magnesium laminated assembly, heating at 310 DEG C-400 DEG C, carrying out final rolling compounding to obtain the steel/magnesium final composite plate strip, and finally, carrying out diffusion annealing to obtain the steel/magnesium laminar composite plate strip. According to the technical scheme, high-strength metallurgical bonding between magnesium and steel can be achieved, and the method is particularly suitable for preparing the steel/magnesium laminar composite plate strip with the large size and the large coil weight, and the magnesium layer of the steel/magnesium laminar composite plate strip is far thicker than the steel layer.