15results about How to "Improve tissue uniformity" patented technology

This invention relates to a steel for automobile engine pistons and its manufacturing method. The chemical composition of the steel, by weight percentage, is: C: 0.41–0.47%, Si: 0.15–0.35%, Mn: 0.70–1.00%, Cr: 1.10–1.40%, P: ≤0.020%, S: 0.015–0.035%, Mo: 0.17–0.27%, Al: 0.010–0.030%, N: 0.0040–0.0060%, with the balance being Fe and unavoidable impurities. The microstructure consists of ferrite and pearlite, with uniform distribution of ferrite and pearlite structures. The geometric center distance between each ferrite and pearlite structure is 15–30 μm. The hot-rolled hardness of the steel is ≤230 HBW, and the banded structure in the steel is ≤1.5 grade. The product features a narrow range of carbon deviation in cross-section, shallow decarburized layer and microcrack depth on the steel surface, low hot-rolled hardness, good banded structure, and high tensile strength after quenching and tempering.

This invention discloses a method for preparing high-entropy ceramic matrix composites using a reactive infiltration process, belonging to the technical field of ceramic matrix composites. The steps are as follows: at least four single-component carbides are ball-milled and mixed with a carbon source, then dispersed in a dispersion liquid to obtain a slurry; continuous fibers are woven into a preform, and an interface layer and a matrix layer are deposited to obtain a semi-dense composite material; the slurry is introduced through vacuum or pressure impregnation; and a high-entropy carbide matrix is ​​generated in situ and densified by reactive infiltration after embedding with a transition metal and its alloy. This invention solves the problems of long process cycles, high porosity, high cost, and insufficient introduction of high-entropy ceramics in existing processes, achieving rapid densification and improving the material's high-temperature stability, oxidation resistance, and ablation resistance. It is suitable for the large-scale production of thermal protection materials for hypersonic vehicles.

The present application relates to a kind of high-precision cold-rolled screw with medium carbon steel hot rolled wire rod in metallurgical technology field, preparation method and application.The present application is aimed at solving the technical problems of low first processing qualified rate of cold-rolled screw caused by poor material organization uniformity and low purity.The chemical composition of the wire rod according to the present application is as follows: C 0.52-0.58%, Si 0.15-0.35%, Mn 0.70-0.90%, Cr 0.10-0.35%, Al 0.015-0.045%, Ti≤0.0025%, [O]≤0.0015%, [N]≤0.0060% and the like, with the balance being Fe.The preparation method of the present application obtains uniform organization with cross-section hardness range ≤20HV through the combined action of narrow component design, continuous casting end electromagnetic stirring, high temperature diffusion annealing and "fast first and slow later" controlled cooling process.The present application is mainly used for manufacturing high-precision ball screw, and the finished product precision reaches more than 5 levels, with first cold-rolled forming qualified rate ≥85%.

This invention relates to a large-size, high-density, high-carbon, high-silicon hot-rolled round steel bar and its preparation method. The chemical composition of the hot-rolled round steel bar, by weight percentage, includes: C: 0.60%~0.70%, Si: 1.70%~1.95%, Mn: 0.80%~0.90%, P≤0.015%, S≤0.015%, Cr: 0.80%~0.90%, Ni: 0.20%~0.25%, Mo: 0.05%~0. 0.10%, Al: 0.015%~0.035%, N: 0.0045%~0.010%, with the remainder being Fe and unavoidable impurities; it can balance toughness and wear resistance, and under the high carbon, high silicon, and high chromium composition system, it can effectively improve the internal density of hot-rolled round steel with a maximum φ110mm specification, meet the stringent flaw detection requirements of equivalent "≤φ1.3", and is suitable for the high-strength and high-wear working conditions of coarse copper ore grinding balls.

The application discloses a kind of multi-modal adaptive furnace temperature control method, system and continuous annealing furnace based on space-time thermal field decoupling, multiple independent heating zones are provided in the continuous annealing furnace, multiple groups of staggered arrangement burners are arranged in each heating zone, four-stage adaptive control strategy based on temperature ratio segmentation and thermal field space-time distribution collaborative control, including: fast response heating zone, proportional regulation transition zone, pulse cross uniform zone, dynamic thermal field maintenance zone. By decoupling furnace temperature control and thermal field spatial distribution, using the way of spatial grouping pulse activation + time staggered control, the rapid response, accurate regulation and uniform maintenance of furnace temperature are realized.The application effectively solves the technical problems of temperature overshoot, response lag, thermal field unevenness, high energy consumption and other technical problems in the traditional control mode, significantly improves the quality of strip steel heat treatment and energy utilization efficiency.

This invention belongs to the technical field of additive manufacturing technology and discloses an in-situ oxygen-controlled composite scraper and a laser selective melting device equipped with the in-situ oxygen-controlled composite scraper. The bottom of the composite scraper includes a second scraper (16), an air jet unit, and a first scraper (18) arranged sequentially along the powder spreading direction. It has an internal gas storage chamber (15) and a powder drop chamber (19). The first scraper is used to evenly spread the powder raw material to form an initial powder layer. The air jet unit performs in-situ oxidation treatment on the surface of the initial powder layer by spraying oxygen-containing gas. The second scraper is used to level and compact the powder layer after the in-situ oxidation treatment. This invention improves the composition and structure of the composite scraper and utilizes the overall cooperation of the first scraper, the air jet unit, and the second scraper to generate a synergistic mechanism of powder spreading, in-situ oxidation, and secondary compaction, breaking through the process limitation that it is difficult to construct oxide dispersion-strengthened structures in-situ during additive manufacturing.

This invention relates to a hot-rolled wire rod for 2300MPa grade stranded wire and its manufacturing method. The method involves rolling high-Si, high-carbon components containing trace amounts of Nb into wire rods, followed by online molten salt isothermal toughening treatment. This process involves a pre-treatment molten salt stage followed by rapid cooling, transitioning the wire rod from an austenitic state to a sorbite phase, forming a structure dominated by sorbite. A subsequent molten salt stage further reduces the molten salt temperature and circulation rate, promoting the continued transformation of untransformed residual austenite into sorbite, followed by isothermal tempering and partial melting of sorbite lamellars. Finally, the wire rod undergoes slow cooling on a roller conveyor, resulting in a hot-rolled wire rod with a microstructure comprising tempered sorbite, ferrite, and melted sorbite. This achieves a tensile strength of 1530~1580MPa, a reduction of area of ​​35%~40%, and a mechanical property difference of ≤48MPa between different coils. This method balances material cost and production efficiency, eliminating the need for offline heat treatment and promoting efficient and stable production of ultra-high strength stranded wire.

The application discloses a kind of high-strength plastic β titanium alloy strip and whole-process preparation method, the β titanium alloy strip is composed of the following mass percentage components: Cr 7.7%~8.3%, Mo 4.9%~5.5%, V 4.9%~5.5%, Al 2.7%~3.3%, Fe≤0.20%, C≤0.03%, N≤0.02%, H≤0.010%, O≤0.10%, and the rest is Ti;The preparation method comprises: one, forging;Two, hot rolling;Three, cold rolling;Four, heat treatment.The β titanium alloy strip and whole-process preparation method of the application are overall planning from component design to final heat treatment whole-process procedure, improve production efficiency, shorten preparation time, and the β titanium alloy strip solid solution state microstructure is equiaxed β fine grain structure, strength-plasticity matching is high, horizontal longitudinal organization performance is uniform, with excellent comprehensive mechanical properties, applicable to metal processing field.

The application discloses a kind of micro-nano hard ceramic phase composite reinforced laser cladding nickel-based wear-resistant coating and its preparation method and application.The preparation method uses discharge plasma ball milling process to mix micro-nano hard ceramic and Ni-based metal powder for modification treatment, utilizes the synergistic effect of plasma activation and mechanical ball milling force of pulse discharge, effectively breaks the nano ceramic phase agglomerate, realizes the uniform dispersion distribution of nano ceramic phase in composite powder;By adopting the optimization of laser cladding process parameters, and cooperating with ultrasonic vibration auxiliary and / or pulse laser composite energy input, etc. Regulating means, prepare the nickel-based wear-resistant coating with uniform and dense structure, high hardness, excellent wear resistance and good metallurgical bonding with base material, which can meet the service requirements of mining machinery, oil drilling and production, metallurgical roller and other harsh working conditions, and has wide application prospect.

This invention relates to a hot-rolled wire rod for 2330MPa grade stranded wire and its manufacturing method. The method involves rolling high-carbon, high-silicon Cr-V wire rods into wire rods, followed by online molten salt isothermal toughening treatment. This process involves a pre-treatment molten salt stage followed by rapid cooling, transitioning the wire rod from an austenitic state to a sorbite phase, forming a predominantly sorbite microstructure. A subsequent molten salt stage further increases the molten salt temperature and reduces the molten salt circulation rate, promoting the continued transformation of untransformed residual austenite into sorbite and isothermal tempering, while also promoting partial melting of sorbite lamellars. Finally, the wire rod undergoes slow cooling on a roller conveyor, resulting in a hot-rolled wire rod with a microstructure consisting of tempered sorbite, ferrite, and melted sorbite. This method controls material costs, achieving a tensile strength of 1558~1608MPa and a reduction of area of ​​34%~39%, while balancing production efficiency and energy consumption. It eliminates the need for offline heat treatment, enabling efficient and stable production of ultra-high strength stranded wire.

The application relates to the technical field of Ti2AlNb alloy processing, in particular to a Ti2AlNb alloy rod and a preparation method and application thereof. The preparation method of the Ti2AlNb alloy rod comprises the following steps: performing upsetting and drawing cycles on Ti2AlNb alloy ingots at 1050-1170 DEG C, 1010-1040 DEG C and 920-950 DEG C respectively; the number of the upsetting and drawing cycles at each temperature range is at least 3 times; and the deformation amount in the upsetting and drawing cycles is 25%-60%. The preparation method reduces the temperature points of rod forging, the upsetting and drawing forging needs 3 times of furnace loading, through the mode of multiple times of furnace re-melting of the same temperature hot material, the forging process is effectively shortened under the condition of guaranteeing that the quality of the rod is not reduced, the rod yield is increased to more than 75%, and meanwhile, the flaw detection level is obviously improved, the flaw detection level of the Ti2AlNb alloy rod with a diameter of 400 mm is increased from Phi 3.2 mm-6dB to Phi 2.0 mm-6dB.

The application discloses a medium-carbon martensitic stainless steel with refined structure and a manufacturing method thereof. The steel has a more uniform structure and better corrosion resistance. The chromium-nickel equivalent ratio of the material is less than or equal to 1.50, the residual austenite phase is greater than or equal to 3%, the hardness after dispersoid carbide precipitation is greater than or equal to 52.5HRC, the hardness difference of the same plate is less than or equal to 1.0HRC, and the pitting point is greater than or equal to 105mV, which is 100% higher than that of 4Cr13. The material can be used in the fields of compressor valve plates and medical devices.

This invention relates to a short-process preparation method for T3-state Al-Cu-Mg-Mn alloy sheets, and is situated in the field of aluminum alloy preparation technology. The invention addresses the technical problems of time-consuming and costly homogenization annealing, as well as the difficulty in achieving both desirable and undesirable performance characteristics in traditional processes. The method involves raw material weighing and batching, alloy smelting, melt refining, alloy casting, direct heating and rolling of ingots, solution treatment, and aging. By strictly controlling Fe and Si impurities to avoid the formation of coarse primary phases, precisely regulating Cu content to balance strengthening and corrosion resistance, increasing Mn content to compensate for strength loss, and eliminating homogenization annealing, the production cycle is shortened by more than 30%, and manufacturing costs are reduced by more than 20%. The prepared T3-state sheets meet aerospace standards in terms of mechanical properties and corrosion resistance, demonstrating promising prospects for industrial application. This invention is used to prepare T3-state Al-Cu-Mg-Mn alloy sheets.

This invention provides a variable-temperature forging process for difficult-to-deform lightweight aluminum / magnesium alloys. The process involves determining the recrystallization temperature to lock in the preheating temperature; heating the difficult-to-deform aluminum or magnesium alloy billet to the preheating temperature; maintaining a die temperature 50-200°C higher than the billet temperature; implementing an initial temperature transfer deformation process on a forging press, with the die at a high temperature and the billet at a low temperature; ensuring the die temperature is 50-200°C higher than the billet temperature; performing plastic deformation at the same temperature for both the die and the billet when the forging deformation reaches 1 / 3-2 / 3 of the stage; maintaining pressure with the die temperature 50-100°C lower than the billet temperature; water quenching the formed forging, followed by aging heat treatment. This variable-temperature forging process for difficult-to-deform lightweight aluminum / magnesium alloys reduces the tendency for deformation damage during deformation, ensures low-temperature deformation of the workpiece without damage or cracking, improves the deformation uniformity of the workpiece, and optimizes its microstructure and mechanical properties.

This invention discloses a high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting. The designed alloy composition contains Mn and Mg elements, and alloying is achieved through La or Ce elements, which can refine α-Al grains, fully utilize the role of Mn, reduce segregation and suppress hot cracking tendency, and improve the microstructure uniformity of alloy ingots or castings. The designed as-cast alloy, after solution treatment and graded aging treatment, yields a final sample with a tensile strength of not less than 552 MPa and an elongation of not less than 7.2%. This invention differs from refining α-Al grains by adding refining agents or inoculants to promote nucleation of particles in the aluminum melt. Instead, it achieves grain refinement through composition design and under general solidification technology conditions, simplifying the melting process and casting process.