795 results about "Alloy element" patented technology

The invention relates to the technical field of manufacturing of engineering machinery parts, and discloses an engineering machinery driving wheel made of a medium carbon alloy cast steel material. The invention also discloses a preparation process of the engineering machinery driving wheel material, which comprises the following steps: S1, casting treatment: melting the medium carbon alloy steel material, and casting into a driving wheel blank; s2, normalizing heat treatment: carrying out normalizing heat treatment on the driving wheel blank; s3, rough machining treatment; s4, quenching treatment: carrying out induction quenching treatment; and S5, finish machining treatment. The synergistic effect of alloy elements in a medium carbon alloy cast steel material is combined with an optimized air cooling process, so that the cast steel is normalized to obtain a uniform structure which mainly contains superfine pearlite and contains extremely little ferrite, the matrix hardness is stable, and the requirement of a high-performance driving wheel is completely met; after the process route is improved, tempering and shot blasting and flaw detection procedures after tempering are canceled; the technological process is greatly shortened, material turnover is reduced, and the production efficiency is improved.

The invention discloses a machine learning guidance laser forming ultrahigh strength and toughness steel design method based on fusion of physical and chemical characteristics, which combines the physical and chemical characteristics with Shapley additive interpretation and analysis, and overcomes the limitation that a traditional pure data driving model lacks theoretical support. The quantitative analysis of the influence between the input characteristics and the output performance is realized, the internal association between the physical and chemical characteristics and the material strengthening and toughening theoretical mechanism is disclosed, the contribution degree and the interaction effect of each alloy element and the heat treatment process parameters are determined, the theoretical basis of variable screening is provided for multi-objective optimization, and the optimization efficiency is improved. Therefore, the efficiency of obtaining the non-dominated solution set is remarkably improved. According to the method, the physical and chemical characteristic combination can be conveniently and rapidly determined, the relation between the input characteristic and the output performance can be quantified, and optimal design of the laser forming ultrahigh strength and toughness steel alloy components and the heat treatment process is achieved.

The application provides an aluminum alloy, which comprises the following components in percentage by mass: Zn 4.0-5.0%, Mg 1.2-1.8%, Cu 0.1-0.3%, Zr 0.08-0.12%, Ti 0.02-0.06%, Fe less than or equal to 0.25%, and the balance of Al. The alloy elements containing Zn 4.0-5.0%, Mg 1.2-1.8%, Cu 0.1-0.3%, Zr 0.08-0.12%, Ti 0.02-0.06% and Fe less than or equal to 0.25% are added into a smelting furnace together with pure aluminum, smelted at 700-750 DEG C to form a melt, refined by blowing in inert gas or adding a refining agent, and the gas and inclusions are removed. The application utilizes the shearing force generated by the different rotating speeds of the upper and lower rollers of a differential rolling mill to break the coarse structure, refine the grains, and increase the dislocation density. The aluminum alloy is rolled at 480-500 DEG C to reduce the deformation resistance, promote dynamic recrystallization, maintain the processing performance, and further enhance the performance by 60-70% of the total deformation. After rolling, the aluminum alloy is subjected to multi-directional forging, the strain direction is changed multiple times, the grains are broken, the structure is homogenized, and anisotropy is eliminated, so that the comprehensive performance and application range of the aluminum alloy profile are improved. The problem that the structure cannot be refined and the dislocation density cannot be increased during the rolling process is solved.

The invention discloses a diesel engine piston material, a diesel engine piston casting method and a diesel engine piston, and relates to the technical field of composites.The diesel engine piston material comprises, by weight, 12.0%-12.5% of Si, 5.6%-5.8% of Cu, 3.0%-3.4% of Ni, 0.1%-0.3% of Mg, 0.1%-0.3% of Mn, 0.4%-0.6% of Fe, 0.10%-0.14% of Ti, 0.10%-0.14% of V, 0.10%-0.14% of Zr, 0.02%-0.06% of Cr and the balance Al and alkali metal impurity elements. The high-strength and heat-resistant aluminum alloy material special for the diesel engine piston is obtained by taking the aluminum alloy as a base body and coordinating multiple alloy elements and accurately regulating and controlling the proportion of all the alloy elements, the material meets the long-term service requirements of the high-load diesel engine piston at the high temperature of 350 DEG C and under the explosion pressure of 20 Mpa of 107 times or above high-frequency reciprocating loads, and the service life of the high-load diesel engine piston is prolonged. And the working conditions of high detonation pressure and thermal load of the diesel engine piston are met, so that the high-temperature mechanical property, long-term service reliability and safety stability of the piston are improved.

The application provides an aluminum alloy profile with high conductivity and high toughness and a production method thereof, and the aluminum alloy profile has the following components in mass fraction: Si: 0.08%-0.12%, Fe+Cu: 0.8%-1.1%, B: 0.03%-0.05%; wherein (Ti+Cr+V) is less than or equal to 0.006%, the total content of other impurity elements is less than or equal to 0.05%, and the balance is Al. The application selects reasonable alloy element ratio, follows the extrusion process, such as the process of the temperature of a casting bar and the extrusion speed, and ensures that the alloy performance meets the requirements in view of the fact that the aluminum alloy extrusion material needs to be drawn subsequently. The product obtained by the application does not need subsequent annealing treatment, and can obtain the aluminum alloy material with high conductivity and high toughness while meeting certain strength.

The thin-gauge ultrahigh-strength non-oriented silicon steel comprises the following chemical components in percentage by mass: less than or equal to 0.002% of C, 3.1%-4.0% of Si, 0.3%-0.7% of Mn, less than or equal to 0.01% of P, less than or equal to 0.001% of S, 0.5%-1.2% of Als, 0.01%-0.08% of Sn, less than or equal to 0.002% of N, less than or equal to 0.001% of Ti, less than or equal to 0.002% of Nb, less than or equal to 0.002% of V and the balance of Fe and inevitable impurities, and Sieq is equal to [wSi] + 2 [wAl]-0.5 [wMn]. According to the technical scheme, trace alloy elements do not need to be added, the alloy smelting difficulty can be reduced, the smelting production cost is saved, meanwhile, the means of increasing deformation structures and improving the content of silicon, aluminum and manganese elements are adopted, and the material has the advantages of being high in strength, high in electromagnetic performance and excellent in machinability at the same time.

The invention discloses a microalloyed high-toughness martensitic stainless steel cutter head as well as a preparation method and a preparation mold thereof. Stainless steel comprises the following components in percentage by weight: 0.3%-0.7% of C, 0.3%-1.0% of Si, 0.5%-1.5% of Mn, 16%-18.5% of Cr, 1%-2% of Ni, 0.3%-0.8% of Mo, 0.1%-0.35% of V, 0.1%-0.25% of Nb, less than or equal to 0.02% of S, less than or equal to 0.02% of P and the balance of Fe. Firstly, raw materials are smelted into molten iron; then adding a deoxidizing agent and precoated sand into the molten iron for molding, and performing sand mold casting and pouring to obtain a cutterhead blank; carrying out heat treatment on the cutter head blank; and finally, shot blasting and polishing are conducted on the cutterhead subjected to heat treatment. The martensitic stainless steel cutterhead has a metallographic structure which takes a martensitic structure as a main structure, takes austenite as an auxiliary structure and dispersedly distributes CrC, VC and NbC particles, the hardness of the martensitic stainless steel cutterhead is 40-45 HRC, the impact toughness of the martensitic stainless steel cutterhead reaches 92-95 J / cm < 2 >, the abrasion resistance of the cutterhead is longer, the service life of the cutterhead is longer, and the abrasion loss of the martensitic stainless steel cutterhead is reduced by 70% compared with a cutterhead without alloy elements.

The invention provides a metal material surface treatment method based on the synergistic effect of solid solution-aging heat treatment and laser shock. The metal material surface treatment method is used for remarkably improving the mechanical property of a metal material and the uniformity and stability of a microstructure. Different from a traditional single laser shock peening process, the heat treatment method is combined with laser shock, and the double effects of structure optimization and mechanical property enhancement are achieved. Specifically, firstly, alloy elements are subjected to sufficient solid solution in a matrix through solid solution-aging heat treatment, heat preservation is conducted at the low temperature so that a strengthening phase can be promoted to be separated out again, and the strengthening phase which is evenly and stably distributed is obtained; and then laser shock is applied to the surface of the material, deep residual compressive stress is introduced into the surface layer through high-energy pulse laser, and a nanocrystalline layer structure is formed. According to the synergistic process, the microstructure stability and uniformity of the material are effectively improved, and the mechanical property of the material is remarkably improved. The technology is suitable for the fields of aerospace, automobile lightweight structures, rail transit and the like, and has wide industrial application prospects.

The invention discloses a method for preparing bainite steel through multi-element microalloying, and belongs to the technical field of advanced steel and iron materials. The method comprises the following steps that a forged steel ingot is subjected to first austenitizing and cooling treatment, and a martensite matrix is obtained; and then secondary phase precipitation treatment, secondary austenitizing treatment and cooling are sequentially carried out, and the bainite steel is prepared. According to the invention, an innovative heat treatment process path of martensite initial structure-medium-temperature second phase precipitation-short-time austenitizing-salt bath isothermal bainite transformation is constructed, and the synergistic effect of microalloy elements such as V, Nb, Ti and B is combined, so that the heat treatment process has the advantages that the heat treatment efficiency is greatly improved on the premise of not depending on precious alloy elements such as Cr and Ni; and the superfine bainite steel which is uniform in structure and excellent in comprehensive performance is successfully prepared.

The invention relates to a delayed fracture resistant non-quenched and tempered 14.9-grade high-strength cold heading steel wire rod and a preparation method thereof. The wire rod comprises the following chemical components: 0.33%-0.55% of C, less than or equal to 0.10% of Si, 1.5%-2.3% of Mn, 0.4%-0.6% of Cr, 0-0.04% of Nb, 0-0.1% of V, 0-0.1% of Ti, 0.004%-0.008% of B, more than or equal to 0.020% of Als, less than or equal to 0.040% of Alt, less than or equal to 0.015% of P, less than or equal to 0.010% of S, less than or equal to 1ppm of H and the balance of Fe and impurity elements. Fine control is adopted in the steelmaking process, the H content is strictly controlled to be lower than 1 ppm, a hydrogen trap is manufactured by adding microalloy elements such as Nb, V and Ti, and the delayed fracture resistance is improved; the air cooling speed of the rolled hot-rolled wire rod is precisely controlled, so that the structure of the hot-rolled wire rod is lath bainite, and high strength is realized by utilizing a medium-carbon bainite structure; the finished wire rod has high strength, high plasticity, excellent low-temperature impact toughness and good delayed fracture resistance.

The invention belongs to the field of profile steel production, and particularly relates to a rolling method of hot-rolled Q450NQR1 weather-resistant H profile steel, which adopts a reversible cogging mill and a universal finishing mill group for rolling: after the cogging mill rolls for 3-5 passes for cogging, a universal continuous rolling mill is adopted for finish rolling 9 continuous rolling, and the arrangement sequence of finish rolling hole patterns is U1-U2-U3-E4-U5-U6-U7-E8-U9; wherein the U3 and the U6 are curved web hole patterns, and the vertical roll is in drum-shaped design. The method has the advantages that one BD cogging mill is used for large-rolling-reduction rolling to crush crystal grains, and then the nine-rack universal continuous rolling mill is used for finish rolling, so that the metal flowing and steel biting conditions are improved. The grain structure is refined through large rolling reduction and low-temperature rolling, the problems that the Q450NQR1 weathering resistant steel is poor in metal fluidity, prone to cracking and the like due to alloy elements are effectively solved, and meanwhile the mechanical property, the size precision and the surface quality of products are guaranteed.

The invention belongs to the technical field of additive manufacturing, and particularly relates to a diamond / copper radiator manufacturing method based on 3D printing, and the diamond / copper radiator manufacturing method comprises the steps that diamond / copper composite powder is prepared, and the composite powder comprises diamond particles with nano alloying elements attached to the surfaces and spherical copper powder; and under shielding gas, green laser with the wavelength of 532 nm is adopted for conducting selective laser melting scanning on the composite powder, meanwhile, high-frequency ultrasonic vibration is applied to a molten pool in a laser acting area, and a diamond / copper composite material radiator green body is formed through layer-by-layer powder laying, scanning melting, ultrasonic assistance and layer-by-layer accumulation. Copper matrix crystal grains are refined through ultrasonic energy, residual stress in the printing process is reduced, generation of microcracks is effectively restrained, the mechanical property and reliability of a workpiece are improved, the high absorptivity of green laser to copper and the technical advantages of 3D printing are combined, and high-quality 3D printing is achieved. And the radiator with fine structures such as complex three-dimensional micro-channels and ultrathin fins can be integrally manufactured.

The invention relates to a low-cost high-strength corrosion-resistant magnesium alloy and a preparation method thereof. The magnesium alloy comprises the following components in percentage by mass: 6-11% of Al, 0.4-0.6% of Zn, 0.2-0.6% of Mn, 0.2-0.4% of Y, 0.2-0.6% of Ca and the balance of Mg and inevitable impurities. A small amount of Ca and Y elements are added, on one hand, an alpha-Mg matrix structure can be refined, beta phase distribution is more uniform, and the mechanical property is improved; and on the other hand, the solid solubility of the alloy element Y in an alpha-Mg matrix can be improved by adding the Ca element, the compactness of a surface oxidation film and a corrosion product film is promoted, compared with other rare earth elements, the potential difference between Al-Ca and Al-Y phases formed by Ca, Y and Al and the magnesium matrix is smaller, micro galvanic corrosion is smaller, and the corrosion resistance of the alloy is remarkably improved.

The invention provides a cold machining manufacturing method of an ultra-fine grain seamless steel pipe. The method comprises the following steps: firstly, selecting a low-alloy structural steel billet with specific components, which comprises C, Si, Mn and microalloy elements of Nb, V and Ti, and heating, perforating and hot-rolling to prepare a pierced billet; and then multi-pass cold deformation treatment is carried out, 5-8 times of cold drawing or cold rolling is carried out on the pierced billet, the deformation of each pass is not lower than 30%, the cold drawing or cold rolling is carried out at the room temperature at the specific speed, and natural cooling is carried out between the passes. Recrystallization annealing is carried out after each pass of cold deformation, heat preservation is carried out for 1-2 hours at the temperature of 650-750 DEG C, and then controlled cooling is carried out. And finally, a finished product is obtained through straightening, head and tail cutting and nondestructive testing. According to the method, through cyclic cooperation of multi-pass cold deformation and recrystallization annealing and the effect of synergistically inhibiting grain growth of microalloy elements, the internal structure of the steel pipe is fully refined and homogenized, and then the comprehensive mechanical properties of the strength and toughness of the finished seamless steel pipe are remarkably improved; and meanwhile, the technological process is stable and controllable, and the product surface quality is excellent.

The invention discloses a high-performance Cu-Co-Si alloy plate and a preparation method thereof, and belongs to the technical field of copper alloy materials. The alloy plate comprises the following components in percentage by weight: 1.0-2.5% of Co, 0.2-1.0% of Si, 0.09-0.2% of Cr, 0.01-0.1% of Ni, less than or equal to 0.2% of Ti, less than or equal to 0.5% of Fe, less than or equal to 0.5% of Sn, less than or equal to 0.5% of Zn, less than or equal to 0.5% of P and the balance of Cu and inevitable trace impurities. The preparation method comprises the steps of smelting, semi-continuous casting, hot rolling, cold rolling, cleaning, stress relief annealing, solid solution, final cold rolling, aging and the like. According to the invention, alloy elements are reasonably matched and a preparation process is optimized, so that the alloy plate forms a nanoscale dispersed precipitated phase, dislocation motion is effectively hindered, grains are refined, and synergistic improvement of strength, conductivity and processability is realized. The thickness of the finished board is (0.02-0.15) + / -0.003 mm, the hardness is 180-220 HV, the electric conductivity is 62-66% IACS, the tensile strength is 620-680 MPa, 90-degree bending R / t is 0.5, and the finished board is free of surface defects and can be widely applied to the electronic and electrical field with high reliability and high performance.

The invention relates to the technical field of steel structures, in particular to a hot forming component and a preparation method thereof.The hot forming component comprises, by mass, 0.27%-0.4% of C, 0.3%-0.8% of Si, 1.0%-2.0% of Mn and 0.2%-0.8% of Cr and contains Nb, V, Ni and trace rare earth Ce, V / Nb = 2.0-4.0, and Nb + V + Ni is smaller than or equal to 0.45%, through the synergistic effect of low C and Nb-V-Ni-Ce, the ultra-high strength of the hot forming component is kept, meanwhile, the limit sharp cold bending angle is increased, and the strength of the hot forming component is improved. By accurately controlling the V / Nb ratio and limiting the total amount of Nb, V and Ni, it is ensured that microalloy elements give full play to fine grain strengthening and precipitation strengthening effects, meanwhile, element waste is avoided, trace rare earth Ce is introduced, the inclusion form is improved, the microscopic structure is optimized, and the comprehensive performance of a hot forming component is remarkably improved.

The invention discloses a self-protection flux-cored wire and a production method thereof. The preparation method of the self-protection flux-cored wire comprises the following steps of S1, material treatment, S2, machining and treatment, S3, quality detection and S4, packaging and transportation. According to the target performance of the welding wire, a powder formula is elaborately designed, and the formula generally comprises a slag former for forming slag, protecting a molten pool, controlling metallurgical reaction of the molten pool and improving welding seam forming, a deoxidizer for removing oxygen and nitrogen in the molten pool and preventing pores and embrittlement, and a gas-making agent for generating protective gas through thermal decomposition, a gas hood is formed at the end of the flux-cored wire to isolate air, alloy elements are added into deposited metal to achieve required chemical components and performance, an arc stabilizer is used for improving arc stability, and a small amount of binder is added sometimes to improve powder fluidity or keep the shape after filling, so that the application range of the flux-cored wire is widened, and the flux-cored wire is suitable for industrial production. And the device is suitable for various working environments, and the production quality of the flux-cored wires is improved.

The invention discloses an ultralow-temperature high-toughness non-magnetic steel flux-cored wire for a controllable nuclear fusion device and a preparation method of the ultralow-temperature high-toughness non-magnetic steel flux-cored wire. A special stainless steel strip is adopted to wrap a metal powder type flux core, and the flux core accounts for 29.6%-30.4% of the total mass of the flux-cored wire; the flux core comprises the following components: 14%-18% of electrolytic manganese, 21%-23% of chromium metal, 0.3%-1.0% of ferrotitanium, 4.4%-5.0% of nitrided ferrochromium, 27.5%-28.5% of nickel powder, 0.5%-1.0% of 52 # ferrosilicon, 8%-9% of molybdenum powder, 0.1%-0.3% of lithium fluoride and the balance of atomized iron powder. The problems that an existing non-magnetic steel welding material is insufficient in toughness and high in magnetic conductivity at the ultralow temperature of-269 DEG C are solved by optimizing flux-cored alloy elements of (nickel-chromium-nitrogen) synergistic stable austenite, matching with a manufacturing process of sealed baking and roller die drawing forming of powder at the temperature of 120-140 DEG C and a welding process protected by argon (Ar) with the purity of 99.999%. The AKV2 of a welded joint is larger than or equal to 34J at the temperature of-269 DEG C, the tensile strength is larger than or equal to 620 MPa, the relative permeability is smaller than or equal to 1.02, the problems that nitrogen of an existing solid welding wire is difficult to control, and hardening is easy can be solved, and the welding wire is completely matched with the extreme working condition of a controllable nuclear fusion device.

The invention discloses an alloy aluminum bar containing rare elements and a preparation technology of the alloy aluminum bar. The alloy aluminum bar comprises, by mass, 1.5%-3.3% of Mg, 0.7%-1.1% of Si, 1.0%-1.7% of Cu, 0.15%-0.3% of Y, 0.07%-0.1% of Er, 0.05%-0.11% of Gd, 0.07%-0.24% of La, 0.08%-0.15% of Zr, 0.07%-0.12% of Ti, 0.05%-0.1% of Sc, smaller than or equal to 0.1% of Fe, 0.35%-0.7% of Mn, 0.2%-0.6% of Ni, smaller than or equal to 0.5% of total impurities and the balance aluminum. The preparation process comprises the following steps: burdening: accurately weighing a high-purity aluminum ingot, Al-Y, Al-Zr, Al-Ti intermediate alloy and pure metal according to the components; smelting: melting at 720-750 DEG C, preserving heat, and protecting by argon; cooling to 740-720 DEG C, and adding an intermediate alloy; a refining agent is added for degassing and deslagging, and slagging-off is conducted after standing is conducted for 30 min; casting: the temperature is 720-740 DEG C, the casting speed is 120-200mm / min, the strength of cooling water is 0.06-0.15 MPa, the water temperature is 10-30 DEG C, and online degassing is performed outside the furnace so that the hydrogen content is less than or equal to 0.15 cm / 100g Al; through scientific proportioning of conventional alloy elements such as Mg, Si, Cu and Mn and various rare elements such as Y, Er, Gd, La, Sc, Zr and Ti, the synergistic strengthening effect of the conventional elements and the rare elements is achieved, and the performance bottleneck of a traditional aluminum alloy is effectively broken through.

The application discloses a preparation method of a high-strength cast magnesium alloy, the alloy containing two non-rare-earth strengthening alloy elements of Sr and Ti, wherein the Ti element is preferentially combined with Al to form AlTi or Al3Ti intermetallic compounds and is gathered along the grain boundary, hindering the growth of alpha-Mg grains, the remaining Al element is combined with Mg to form a beta phase, the grain size is reduced, the morphology of the beta phase is improved, and thus the mechanical properties are improved; the Sr element can strengthen the beta phase on one hand, and can consume the Al element at the solidification front by forming a new Al4Sr phase, so that the volume fraction of the beta phase is reduced; in addition, the Sr element can form an adsorption film of strontium on the grain growth interface as a surface active element, so that the grain growth speed is reduced, the alloy has more time to generate more crystal nuclei when solidifying, and the grains are refined; under the synergistic effect of the two elements, the strength of the magnesium alloy is significantly improved.

The invention discloses a design method of an anti-corrosion and wear-resistant reinforced sucker rod, and relates to the technical field of oil exploitation equipment. According to the method, chemical components of the sucker rod are optimized, alloy elements such as chromium, nickel and molybdenum and microalloy elements such as niobium, titanium and vanadium are added, meanwhile, the surface treatment processes of boriding, nickel-phosphorus alloy plating and polyurethane elastomer coating are adopted, all links of the manufacturing process are optimized, and the manufacturing process is optimized. The corrosion resistance, the wear resistance and the comprehensive mechanical property of the sucker rod are obviously improved. Tests prove that the sucker rod adopting the design method can effectively deal with a complex and severe underground environment, the service life is prolonged, the oil extraction operation cost of an oil field is reduced, and the sucker rod has a wide application prospect.

The invention discloses round steel for a phi 300mm large-specification petroleum valve body and a production method of the round steel. The round steel comprises the following chemical components in percentage by weight: 0.17%-0.20% of C, 0.20%-0.30% of Si, 1.23%-1.35% of Mn, 0.015%-0.030% of Al, 0.005%-0.015% of V and the balance of iron and inevitable impurities. On the basis of solution strengthening of C and Mn, V, Al and other fine-grain alloy elements are designed and added, dispersed precipitation of carbon and nitride fine particles and solution strengthening of the V and Al elements are achieved through controlled rolling to refine grains, the strength and toughness of the round steel are greatly improved, it is guaranteed that the grains are fine, and the normalized V-type-50 DEG C low-temperature impact of the round steel is larger than 100 J; and the grain size in the hot rolling state is 6.5-7.0 grade, and the requirements of downstream customers can be completely met.

The invention discloses a heat treatment process of low-carbon chromium molybdenum steel 15CrMoIV. The steel ingot contains microalloy elements such as Nb and V; the method comprises the following steps: firstly, heating a steel ingot to 1240-1250 DEG C, and carrying out primary forging; then forming forging is carried out in the temperature range of 1230-850 DEG C, a multi-pass deformation process including upsetting, multi-directional outer diameter pressing, chamfering, secondary upsetting and double-face spinning is carried out, and the overall forging ratio is strictly controlled to be 3.8-4.2; and after forging, air cooling, high-temperature heat preservation at 910-950 DEG C, fog cooling accelerated cooling and long-time tempering treatment at 630-670 DEG C are sequentially carried out. According to the method, the optimized forging process is combined with a specific heat treatment system, the internal defects of the steel ingot can be fully welded, grain refinement and structure homogenization are promoted, excellent obdurability matching is achieved, and the core quality of the wind power main shaft forged piece is improved.

The invention discloses a pole piece roller forge piece and a preparation method thereof, and relates to the technical field of equipment manufacturing, and the pole piece roller forge piece comprises the following chemical components in percentage by mass: 0.75-1.05% of C; 1.0 to 2.5 parts of Si; 0.3 to 1.0 part of Mn; p: less than or equal to 0.015; s: less than or equal to 0.010; 1.0 to 2.0 parts of Cr; 0.01 to 0.1 part of Nb; v: 0.05 to 0.25 part; mo: less than or equal to 0.2; ni + Cu: less than or equal to 0.6; n is greater than or equal to 200 ppm, and the balance is Fe and inevitable impurities. By optimizing chemical components (for example, the use of precious alloy elements such as Cr and Mo is reduced, and the content of Si is increased), the material cost is remarkably reduced while the performance is guaranteed. Meanwhile, elements such as Nb, V and N are added to form tiny carbonitride, the effects of composite microalloying and grain refining can be achieved, then the high-temperature hardness maintaining capacity of the material is remarkably improved, and the problems that in the prior art, under the high-temperature working condition, the hardness is poor, the material cost is high, the structure uniformity and performance stability are poor, and the high-temperature hardness attenuation is large are solved.

The invention relates to the technical field of photovoltaic cells and materials thereof, and discloses a crystalline silicon wafer for preparing a crystalline silicon photovoltaic cell, a silicon ingot and a laminated photovoltaic cell. The crystal silicon wafer has one of the following characteristics: 1) the crystal silicon wafer is a lithium crystal silicon wafer of lithium-doped silicon; and 2) the crystal silicon wafer is an alloy crystal silicon wafer, the alloy crystal silicon wafer comprises a substrate, an alloy area containing silicon, tin and germanium alloy elements is locally prepared on the substrate, the alloy crystal silicon wafer is formed, and the alloy area of the alloy crystal silicon wafer comprises the following alloy elements in percentage by atomic number: 5-53% of silicon, 2-12% of tin and the balance of germanium. Compared with the prior art, the current output potential is improved, the photoelectric conversion efficiency is improved, lithium in the lithium crystal silicon wafer effectively passivates defects in crystalline silicon, the minority carrier lifetime of the crystalline silicon is prolonged, the mobility of the crystalline silicon is improved, a better lithium interface passivation effect is achieved, and the function of resisting the ultraviolet induced degradation effect is achieved.

This invention discloses a hardening device and method for rolling bearing steel balls, relating to the field of surface hardening treatment technology. The hardening device includes a bath, an elastic base disposed below the bath, a working medium and steel balls inside the bath, the working medium comprising alloy element powder, abrasive powder, and a conductive solution, a pulsed plasma gun positioned above the bath, the outlet end of the pulsed plasma gun inserted into the bath with its axis intersecting the vertical axis of the bath at an acute angle, and an electromagnet for attracting steel balls mounted on the surface of the bath. A matching hardening method is also provided. The technical solution of this invention forms a high-hardness alloy layer on the surface of the steel ball, improving the hardening quality of the steel ball surface and enabling the steel ball to meet the performance requirements for use under high load and corrosive environments.

The invention relates to a method for machine learning aided design of a structural alloy for a fourth-generation thorium-based molten salt reactor, and belongs to the technical field of artificial intelligence auxiliary material design. The method comprises the steps that S1, an alloy component machine learning model for phase composition prediction is established, specifically, based on known alloy sample data, the sample data comprise alloy element content and corresponding phase composition information, and the machine learning model used for predicting alloy phase composition is established; s2, screening an initial alloy component space through phase composition constraint conditions; s3, secondary screening of alloy components based on thermodynamic simulation; s4, alloy sample preparation and solid solution homogenization treatment; s5, carrying out a mechanical property test; and S6, experimental result feedback and machine learning model closed-loop updating are carried out. According to the method, the artificial intelligence technology and the traditional alloy design theory are organically fused, an efficient and reliable new path is provided for research and development of key structural materials for the fourth-generation thorium-based molten salt reactor, and the important scientific research value and the engineering application prospect are achieved.

This invention discloses a high-fluidity, low-casting-defect, and high-strength-toughness Al-Zn alloy and its preparation method, relating to the field of high-performance aluminum alloy materials in aerospace and transportation. The high-fluidity, low-casting-defect, and high-strength-toughness Al-Zn alloy, by mass percentage, comprises the following components: Zn: 5.3-7.3%, Mg: 2.4-3.3%, Cu: 1.4-2.0%, Ni: 0.3-1.3%, Ti: 0.05-0.5%, Zr: 0.03-0.3%, Mn: 0.01-0.2%, Si: ≤0.07%, with Ti and Zr added at a mass ratio of 1-1.5:1. The content of any single impurity is ≤0.03%, and the total impurity content is ≤0.1%, with the balance being aluminum and non-removable impurities. By controlling the content of the main alloying elements and microalloying, the fluidity of the alloy can be improved and casting defects reduced. High-strength and high-toughness alloys can be obtained through heat treatment. The invented alloy has an average spiral flow channel length of ≥700mm, tensile strength of ≥710MPa, yield strength of ≥630MPa, and elongation of ≥8%.

This invention provides a 590MPa grade solid welding wire, a laser-arc hybrid welding process, and a welded joint. The composition system of this invention is precisely adapted to the rapid heating and cooling thermal cycle characteristics and the burn-off law of key alloying elements in laser-arc hybrid welding of 590MPa grade marine engineering steel. By strictly controlling the content of highly hardenable elements such as C, Mn, Ni, and Mo, the formation of hardened structures in the weld metal is avoided. A certain amount of Ti element is added to provide nucleation points within the grains, directionally inducing the formation of a highly oriented and complex acicular ferrite matrix structure, thereby simultaneously improving strength and toughness through grain refinement. At the same time, an appropriate amount of V element is added to further improve the strength margin of the weld metal through microalloying. This welding wire has excellent welding processability and crack resistance, and can achieve room temperature welding without preheating or post-heating, providing material support for the high-quality and high-efficiency construction of marine engineering equipment.

This invention belongs to the field of metallic materials and provides a method for manufacturing a 500MPa grade steel plate that can be welded in a low-temperature environment without preheating. The steel plate adopts a low-carbon, low-manganese chemical composition system and adds microalloying elements such as V-N, Ti, and Mo to refine the grain size. The (Ti+V) / (C+N) ratio is precisely controlled. By adding La, Ca, Mg, and Zr, fine and dispersed oxide particles are formed in the steel, improving the uniformity of performance in the thickness direction of the steel plate. The manufacturing method includes smelting, continuous casting, furnace heating, rolling, online cooling, and tempering. The steel plate produced by this invention has a yield strength of 530~580MPa, a tensile strength of 630~670MPa, an elongation after fracture ≥24%, an impact energy of ≥240J at -80℃, a tensile strength of 650~680MPa after welding in a 0℃ environment, and an impact energy of ≥150J at -60℃ in the heat-affected zone.