81results about How to "Increase grain boundary area" patented technology

The invention relates to a steel plate and a process method thereof used for producing water heater linear enamel by a flexible thin slab rolling line (FTSR), belonging to the production field of enamel steel plates. The steel plate comprises the following chemical components in percentage by weight: 0.03-0.10wt% of carbon, 0.15-0.40wt% of manganese, less than or equal to 0.06wt% of silicon, 0.004-0.040wt% of sulphur, less than or equal to 0.15wt% of phosphorus, 0.03-0.05wt% of aluminum, 0.002-0.008wt% of nitrogen, 0.02-0.10wt% of titanium and the balance of ferrum and inevitable impurities. The tissue of the water heater linear enamel contains fine grain ferrite and a small quantity of pearlite tissues, and the granularity level of the water heater linear enamel is more than or equal to 10 levels. According to reasonable ingredient design and the FTSR process, steel for manufacturing water-storage water heater linear enamel for home appliances is produced; the steel plate has good enamel adhesion and scaling resistance, and also has the characteristics of few added alloy elements, few production working procedures, low production cost and the like; and a hot rolling scouring plate is used for replacing a cold rolling annealing plate.

The invention discloses an iron-based alloy powder material for plasma cladding quick forming, which comprises the following alloy components in percentage by weight: 0.05-0.15 percent of C, 4-8 percent of Ni,10-15 percent of Cr, 0.1-1 percent of B, 0.8-1.2 percent of Si, 0.8-1.2 percent of Mo, 0.25-0.70 percent of Nb, 0.25-3.5 percent of mixed RE(containing 47 percent of Ce, 26 percent of La,18 percent of Nd and 5 percent of Pr in percentage by mass) and the balance of Fe. The iron-based alloy powder with the components is especially suitable for plasma cladding quick forming, and a cladding layer has medium hardness and wear-resistance. The iron-based alloy powder has little tendency to crack and other cladding defects under the condition of multi-layer cladding, and the cladding process is excellent with low powder cost. The powder can be also used for restoring work-piece size or used as a bottom layer before a functional cladding layer is formed during plasma single-layer cladding repair, and can be applied to wider application needs.

The invention discloses a martensite wear-resistant steel plate with high wear resistance, belonging to the technical field of steel manufacturing. According to a technical scheme in the invention, the martensite wear-resistant steel plate comprises the following chemical components by weight: 0.32 to 0.38 % of C, 0.02 to 0.30% of Si, 0.8 to 1.0% of Mn, 0.6 to 0.8% of Ti, 0.02 to 0.03% of Nb, 0.15-0.20% of Mo, 0.35-0.45% of Cr, 0.0010-0.0020% of B, no more than 0.003% of S and no more than 0.012% of P, with the balance being Fe and unavoidable impurity elements. In the process of hot continuous rolling in the invention, TiC particles precipitated through continuous casting are gradually fragmented and homogenized along a rolling direction; through rolling fragmentation and solid-state precipitation of nano-sized TiC, most of the micron-sized TiC particles precipitated through continuous casting disappear; and nano-sized TiC can refine original austenite grains and improve ductility andtoughness.

The invention relates to a thick hot rolled sheet steel with 450MPa grade yield strength and a manufacturing method thereof, and solves the technical problems of cost increase and hot rolling equipment energy consumption increase due to adding of precious alloy elements in existing 450MPa grade yield strength thick hot rolled sheet steel. The thick hot rolled sheet steel with 450MPa grade yield strength provided by the invention comprises the following chemical components by weight percentage: 0.11%-0.16% of C, 0.15%-0.25% of Si, 1.0%-.3% of Mn, less than or equal to 0.018% of P, less than or equal to 0.008% of S, 0.020%-0.035% of Nb, 0.015%-0.025% of Ti, 0.010%-0.050% of Alt, 0.0015%-0.0040% of Ca, and the balance iron and unavoidable inclusions. The product involved in the invention can be used for construction, ocean engineering, engineering machinery and other industries.

The invention provides a preparation method of a shaped charge liner tantalum 5 tungsten material. The preparation method comprises the following steps: A) performing hot forging on a tantalum 5 tungsten cast ingot for three times, wherein a hot forging way is axial upsetting and radial stretching, the upsetting ratio of the axial upsetting is 1.5-2.0, and the stretching ratio of the radial stretching is 0.8-1.0; performing annealing treatment on a tantalum 5 tungsten blank subjected to the hot forging for three times; B) rolling the tantalum 5 tungsten blank subjected to the annealing treatment, wherein the processing rate of rolling is 70-85 percent; C) performing annealing treatment on the tantalum 5 tungsten blank obtained in the step B) to obtain the shaped charge liner tantalum 5 tungsten material. In the process of preparing the tantalum 5 tungsten material, the grain structure inside the prepared tantalum 5 tungsten material is small by adopting the processing methods of the hot forging for three times and the rolling and through controlling parameters in forging and rolling processes, and all mechanical properties are uniform.

The invention discloses a single-ferrite-precipitated steel plate with high strength and a high pore-expansion property and a preparation method for the same. Steel comprises 0.05%-0.12% of C, 0.1%-0.7% of Si, 0.8%-2.2% of Mn, 0.05%-0.10% of Ti, less than 0.035% of P, less than 0.035% of S, 0.015%-0.060% of Als, 0.0015%-0.0050% of Ca, less than 0.0050% of Mg and less than 0.005% of N, at least oneof ingredients including 0.15%-0.3% of Cr and 0.05%-0.3% of Mo, at least one of ingredients including 0.02%-0.06% of Nb and 0.05%-0.25% of V as well as the balance being Fe and inevitable impurities.The linear speed of Si-Ca feeding is more than or equal to 3.5m/s, and a superheat degree of the molten steel is less than or equal to 30 DEG C; and the heating temperature of a casting blank is 1150-1250 DEG C, the multi-pass rolling total reduction rate is more than or equal to 80%, the final rolling temperature of hot rolling is 850-950 DEG C, the after-rolling cooling rate is 15-45 DEG C/s, and the rolling temperature is 550-650 DEG C. The finished steel plate has the good pore-expansion property.

The invention provides a heat treatment process for optimizing 42CrMo low-temperature impact absorbing energy. According to the heat treatment process, during forging discharging, chemical compositions are controlled, the B element is added, and the hardenability is improved; and after forging, different high normalizing temperatures, different high hardening temperatures and the faster cooling manner are adopted, and the better low temperature impact toughness is obtained. In the discharging process, the chemical compositions are added, the B element is added, then forging is performed, forged materials are subjected to high-temperature normalizing and high-temperature tempering, then rough machining is carried out, materials obtained after rough machining is subjected to modulation treatment, and modulation treatment specifically includes high-temperature quenching and high-temperature tempering, and stress relief annealing is carried out after semifinishing.

The invention belongs to the technical field of superconductor preparation, and specifically relates to a superconducting joint and a preparation method thereof. The superconducting joint comprises boron powder, magnesium powder, superconductors, an outer metal sheath and an inner metal sheath, wherein the superconductors and boron powder are coated by the inner metal sheath, a low-melting-point alloy phase is formed at the junction of the inner metal sheath and the magnesium powder when heat treatment is carried out, a liquid phase can be formed when the temperature is lower than 600 DEG C, and the diffusion rate and reaction rate of magnesium for entering the boron powder are accelerated, so that the reaction of the boron powder and the magnesium powder can be conducted at a temperaturelower than 600 DEG C, the crystal grain size of a product MgB2 is reduced, the crystal boundary area is increased, and thus the pinning ability of MgB2 is improved. In addition, the setting of the inner metal sheath can enable the connection efficiency of the superconducting joint not to be limited by the shape of the superconductors.

The invention provides an ultrathin 65Mn cold-rolled wide steel strip and a manufacturing method of the ultrathin 65Mn cold-rolled wide steel strip. According to optimal cold-rolling technological parameters such as the reduction schedule, the rolling force, the rolling speed and the tension for joint production of the ultrathin 65Mn cold-rolled wide steel strip by adopting a 1450mm single-machine-frame six-roller reversible rolling mill and a Sendzimir twenty-roller reversible rolling mill, front-pass large-reduction rough rolling of the six-roller rolling mill and rear-pass thin-specification finish rolling of the twenty-roller rolling mill are achieved, the complementary advantages of equipment are fully achieved, the technical problems that rolling of the ultrathin 65Mn cold-rolled wide steel strip is unstable, the strip is prone to breakage, the plate shape control is difficult, and the rolling difficulty is high are solved, and the situations that the size precision of products is high, the plate shape is flat, and the quality is stable are guaranteed.

The invention relates to the field of copper alloys for toilet and kitchen industries, and provides a preparation method of an anti-dezincification lead-free bismuth arsenic brass pipe. The preparation method comprises the steps of casting as a copper ingot-extrusion as a copper pipe blank-stretching-annealing-inspection of a finished copper pipe-warehousing of the finished copper pipe after smelting of the following raw materials in percentage by mass: 61-63% of Cu, 0.5-0.9% of Bi, 0.07-0.12% of As, 0.5-0.8% of Al, 0.08-0.24% of Sn, Pb not more than 0.1%, and the balance of Zn and impuritieswith a total amount not more than 0.25%.

The invention provides a method for improving wet process formability and sinterability of ceramic nano-powder and belongs to the field of ceramic preparation. According to the invention, ceramic nano-powder is treated by the combination of pelleting and calcining, on the one hand, the nanoscale and high activity (high crystal boundary area has high sintering promoting power) of the ceramic nano-powder are kept, on the other hand, multiple primary particles are controllably calcined together to form second particles (polycrystals or single grain crystals), and therefore, the particles (grain crystals) of the ceramic nano-powder are enlarged, and forming becomes easy. Meanwhile, the crystalline degree of the particles of the ceramic nano-powder is increased by calcining, defects on the surfaces of the particles are reduced, original microcrystals with multiple surface defects (uneven surface) are transformed into microcrystals with relatively smooth surfaces, the specific surface area is reduced, a sizing agent reaches a relatively high solid content in wet process forming, the density of a formed green body is greatly improved, and further a dense sintering body is obtained at relatively low temperature, and the bottleneck problem of difficulty in forming and sintering of the ceramic nano-powder can be effectively solved.

The invention discloses a method for preparing Fe-Ga-In-Tb alloy bar by filtering and undercooling ceramic. A Fe-Ga-In-Tb novel magnetostriction alloy component system is used for overcoming the defect that the iron gallium binary component system alloy is hard to smelt. The method comprises the following steps: firstly filtering an alloy melt through a nano-porous ceramic filter to improve the purity of the Fe-Ga-In-Tb melt, undercooling the alloy melt, and then heating the alloy, enabling an alloy liquid metal to stimulate directional crystallization growth through an undercooling directional crystallization system. The alloy bar prepared by the method disclosed by the invention is smooth in surface, high in directional degree, precise and uniform in component, and good in comprehensive performance.

The invention relates to the field of copper alloys for the bathroom and kitchen industry and provides a preparing method for an anti-dezincification leadless bismuth arsenic extruded brass rod. The preparing method comprises the step of smelting 61-63% of Cu, 0.5-0.9% of Bi, 0.07-0.12% of As, 0.5-0.8% of Al, 0.08-0.24% of Sn, smaller than 0.1% of Pb, the balance Zn and smaller than or equal to 0.25% of impurities to obtain the solid brass rod by the processes of lead casting and extruding.

The invention discloses a method for reducing cracks in titanium-aluminum alloy printed through selective laser melting. The method comprises the following steps that (1) high-niobium titanium-aluminum alloy spherical powder is prepared from a titanium-aluminum alloy bar containing a high-niobium component under the protection of inert gas, wherein the powder comprises 43-49 at% of aluminum element, 6-9 at% of niobium element, no more than 2 at% of trace elements and the balance titanium element; (2) selective laser melting is conducted under the protection of high-purity inert gas to form the titanium-aluminum alloy, wherein the scanning speed is higher than or equal to 1000 mm/s, and the thickness of a powder layer is 20-40 microns; and (3) after forming is finished, a titanium-aluminum alloy formed part is obtained after natural cooling, wherein the microstructure of the titanium-aluminum alloy formed part is homogenized into an alpha2 phase, and the volume fraction of the alpha2 phase is larger than or equal to 90%. According to the method, the residual stress caused by the difference of thermal expansion coefficients among different phase regions is reduced, the microstructure of the titanium-aluminum alloy shows high strength and toughness, grains are fine, and therefore cracks are inhibited.

The invention relates to the field of copper alloys for kitchenware industries, and provides a production method of an anti-dezincification and unleaded lead-cast brass ingot which is good in anti-dezincification corrosion property, high in strength, and good in machining property. The production method comprises the steps that the following raw materials of, by mass, 61-63% of Cu, 0.5-0.9% of Bi,0.07-0.12% of As, 0.5-0.8% of Al, 0.08-0.24% of Sn, less than 0.1% of Pb and the balance Zn and impurities with the total amount being less than or equal to 0.25% are smelted, and then subjected to lead casting, and the brass ingot is prepared.