455 results about "Borium" patented technology

A steel sheet has a chemical composition including in wt % C: 0.2-0.4%, Mn: 0.8-2.0%, Si: 0.1-0.5%, Al: 0.01-0.1%, Ti: 0.01-0.1%, B: 0.0005-0.005%, P≤0.040%, Ca≤0.01%, S≤0.006%, N≤0.01%. The steel sheet includes from the bulk to the surface of the coated steel sheet a bulk and a skin layer occupying the outermost 10% of the thickness on either side of the bulk. The bulk includes an inclusion population in which the sum of clustering indexes of MnS and TiN / Ti(C,N) inclusions is less than or equal to 300 μm / mm2. This allows to manufacture hot pressed parts having a tensile strength equal to or greater than 1300 MPa and a bending anisotropy equal to or lower than 7°.

The utility model relates to a filter assembly, a tail gas treatment device and boron diffusion production equipment, the filter assembly comprises a filter element and a filter cartridge, the filter element is provided with a first end and a second end along a first direction, and the filter element is provided with a plurality of filter through holes along the first direction; the filter element is positioned in the filter cartridge; the filter cartridge is provided with an air inlet and an air outlet; the air inlet is communicated with an exhaust pipe of a vacuum furnace of the boron diffusion production equipment, and the air outlet is communicated with a tail exhaust pipe of the boron diffusion production equipment; tail gas exhausted by the exhaust pipe can enter the filtering through hole through the gas inlet and the first end in sequence, and can be exhausted to the tail exhaust pipe through the second end and the gas outlet in sequence after being filtered; a plurality of water injection blind holes extending in the first direction are formed in the filter element, and openings of the water injection blind holes are formed in the second end; a first water injection port is formed in the filter cartridge and is communicated with the opening through a water pipe; and the filter element is made of a porous material. According to the technical scheme, harmful substances such as B2O3 in the tail gas can be fully and effectively removed, and the filtering efficiency is high.

The invention relates to the technical field of flux-cored wires. The preparation method comprises the following steps: weighing the following raw materials in parts by weight: 4-6 parts of chromium carbide powder, 7-9 parts of molybdenum powder, 6-8 parts of nickel powder, 10-15 parts of niobium powder, 15-18 parts of tungsten carbide powder, 7-11 parts of a modified titanium carbide agent, 5-8 parts of a blending agent added based on boron and 2-4 parts of 30-mesh natural graphite; 1-2 parts of sodium fluosilicate; 1-2 parts of aluminum powder; and 70-75 parts of iron powder. The flux-cored wire can adapt to complex service environments of parts such as rollers and continuous casting crystallizers in the metallurgical industry, the service life of the parts subjected to surfacing repair is prolonged, the production efficiency of the parts subjected to surfacing repair is improved, the obtained flux-cored wire achieves balance of high-temperature performance, mechanical performance and low-temperature stability, and the comprehensive applicability of products is improved.

The invention discloses a composite heavy metal adsorbent synthesized through mineral conversion and a preparation method of the composite heavy metal adsorbent, and belongs to the technical field of deep processing of natural nonmetallic minerals and preparation of heavy metal adsorption functional materials, and the main preparation method comprises the following steps: S1, crushing and crushing natural clay minerals, and sieving with a 80-mesh sieve to obtain mineral powder; s2, mixing the obtained mineral powder with a calcium compound, and carrying out ball milling; s3, adding a boron compound, and continuing ball milling; s4, adding water into a solid material obtained by ball milling according to a solid-to-liquid ratio of (1: 5)-(1: 20), putting into a microwave hydrothermal reaction kettle, adding an organic auxiliary agent, carrying out gradient heating to 100-200 DEG C, reacting for 30-120 minutes, then naturally cooling to room temperature, separating, drying and crushing; according to the invention, natural clay raw ore is taken as a raw material, and the borate-silicate composite adsorption material is prepared in a preparation mode of combining solid-phase reaction and microwave hydrothermal treatment, so that high-concentration and low-concentration heavy metal ions are efficiently removed.

The invention discloses high magnetic induction oriented silicon steel and a production method. The high magnetic induction oriented silicon steel comprises the following components in percentage by weight: 0.032 to 0.065 percent of C, 2.58 to 4.02 percent of Si, 0.014 to 0.036 percent of Als, 0.021 to 0.043 percent of Mn, 0.0015 to 0.014 percent of Nb, 0.0015 to 0.0084 percent of B, 0.0037 to 0.0081 percent of N and 0.004 to 0.015 percent of S. A large amount of B element is added, a proper amount of BN and other congenital inhibitors can be provided, the situation that primary grains are too large is effectively avoided, meanwhile, boron oxide, boric acid and borate are added into the magnesium oxide additive, an acquired inhibitor can be generated with N, an AlN + BN double-inhibitor system is formed, and the stability of magnetic performance is guaranteed; and the temperature is kept at 910-1005 DEG C for 18-25 hours, so that B is fully diffused and forms a new BN inhibitor with N, and the stability of the magnetic performance is effectively improved.

The ultra-high strength cold-rolled steel sheet of the present invention comprises, in wt%: 0.23 to 0.40 wt% of carbon (C); from 0.05 wt% to 1.0 wt% of silicon (Si); 0.5 wt% to 3.0 wt% of manganese (Mn); 0.01% to 0.12% by weight of vanadium (V); 0.01 wt% to 0.3 wt% of aluminum (Al); 0 wt% (exclusive) to 0.5 wt% (inclusive) chromium (Cr); 0 wt% (exclusive) to 0.1 wt% (inclusive) of titanium (Ti); 0 wt% (exclusive) to 0.02 wt% (inclusive) phosphorus (P); 0 wt% (exclusive) to 0.01 wt% (inclusive) of sulfur (S); from 0.001% by weight to 0.005% by weight of boron (B); the remainder being iron (Fe) and other unavoidable impurities, wherein the final microstructure of the steel sheet includes tempered martensite at a volume fraction of 90% or more; the average pitch between precipitates in the tempered martensite is 300 nm or more, the average size of the precipitates is 200 nm or less, and the number of precipitates having an average size of 40 nm or less is 25 or more based on the area of 20 [mu] m2 in the final microstructure.

In one aspect, evaporator boats are provided which, in some embodiments, exhibit resistance to corrosion and associated performance degradation imparted by exposure to molten metals, including aluminum. An evaporator boat described herein comprises a body and an evaporator surface, the body comprising a boron nitride (BN) component and a TiB2 component including a solid solution of TiB2 and one or more elements selected from the group consisting of silicon and metallic elements of Groups IVB-VIIIB of the Periodic Table.

A high-manganese hot-rolled steel having a composition containing the following elements: 0.8% < = carbon < = 1.3%, 9.5% < = manganese < = 22%, 0.01% < = silicon < = 3%, 0.01% < = aluminum < = 3%, 0.03% < = phosphorus < = 0.1%, 0.03% < = sulfur < = 0.1%, 0% < = nitrogen < = 0.01%, 0% < = niobium < = 0.03%, 0% < = titanium < = 0.2%, 0% < = chromium < = 1.5%, 0% < = molybdenum < = 0.5%, 0% < = calcium < = 0.005%, 0.01% < = copper < = 2%, 0.01% < = nickel < = 3%, 0% < = boron < = 0.01%, 0% < = magnesium < = 0.005%, the remainder is composed of iron and inevitable impurities due to processing, the microstructure of the steel contains, in area fraction, 95% or more of austenite and 0% to 5% of carbide, and the grain size of grains of the austenite is 15 [mu] m or more.

The invention provides a method for preparing austenite aging steel based on injection molding, and belongs to the technical field of steel materials. The modified raw materials such as the sulfur-carbon-molybdenum composite powder, the nitrogen-nickel composite powder and the boron-phosphorus-chromium composite powder are matched with the components such as the silicon powder, the manganese powder and the iron powder, the austenite aging steel is obtained through injection molding, the density of the austenite aging steel material is improved, and meanwhile the mechanical property and hardness of the austenite aging steel material are improved.

The invention discloses an efficient refining method for red impure copper. The efficient refining method comprises the following steps: (1) preparing calcium-cerium composite oxide powder; (2) preparing boron-phosphorus doped powder; (3) preparing a refining auxiliary agent; (4) red impure copper is put into a crucible, a medium-frequency induction furnace is adopted for heating and melting the red impure copper into a melt, the melt is covered with charcoal after being completely melted, the temperature of the melt is kept at 1110-1120 DEG C, then the refining auxiliary is added, and the mass ratio of the refining auxiliary to the melt is (3-4) kg: 1 t; and after charging, stirring the melt at a constant temperature of 1110-1120 DEG C for 10 minutes, then standing for 15 minutes, deslagging, casting and molding to obtain the refined impure red copper. After refining through the method, the tensile strength and the electric conductivity of the impure red copper can be remarkably improved, and the use performance of the impure red copper is improved.

The present invention belongs to the technical field of ceramic preparation, and relates to a preparation method and device for a high-purity porous boron carbide nuclear control rod. The present invention uses boron trichloride gas as the boron source, methane as the carbon source, argon as the carrier gas and protective gas, and hydrogen as the catalytic gas and reducing gas to prepare a high-purity porous boron carbide nuclear control rod. The method of increasing the deposition temperature of boron carbide step by step and region by region from the back to the front is adopted, which can not only improve the deposition rate of boron carbide, but also ensure that the physical and mechanical properties of each part of the prepared high-purity porous boron carbide nuclear control rod are consistent. By changing the particle size of the boron carbide powder for preparing the boron carbide blank and coordinating the adjustment of temperature, flow rate, pressure and deposition time, the porosity and pore size of the prepared high-purity porous boron carbide can be regulated and a high total boron and carbon content can be obtained, so as to meet various actual requirements.

The invention discloses special hot work die steel for large-scale integrated die casting and a preparation method of the special hot work die steel, and belongs to the technical field of hot work die steel. The steel comprises the following chemical components in percentage by mass: 0.28%-0.35% of C, 0.01%-0.025% of La, 0.01%-0.02% of Ce, 0.4%-0.45% of Mn, 0.1%-0.2% of Si, 4.5%-5.5% of Cr, 1.50%-2.00% of W, 2.2%-2.8% of Mo, 0.8%-1.2% of V, 1.0%-1.5% of Co, 0.1%-0.3% of Nb and the balance of Fe and impurities (S and P are less than or equal to 0.015%). The preparation method comprises the composite processes of vacuum induction melting and electroslag remelting purification, hydrogen firing high-temperature homogenization and three-upsetting and three-drawing multi-directional forging, spheroidizing annealing and subzero treatment, step quenching and double tempering, multi-element co-permeation, supersonic particle bombardment surface nanocrystallization and plasma boriding. The rare earth element La / Ce refined grain boundary is combined with multi-element alloy strengthening and surface nanocrystallization-boronizing synergistic treatment, so that the hardness, impact toughness and thermal fatigue life of the die steel are remarkably improved, and the die steel is suitable for high-temperature, high-pressure and high-wear working conditions of a large integrated die-casting die.

The invention discloses a heat treatment process for improving the obdurability of die steel, and belongs to the technical field of metal heat treatment. The invention relates to a heat treatment process for improving the toughness of die steel, which adopts a die steel material with a specific component proportion, and the die steel material comprises carbon, chromium, molybdenum, vanadium, tungsten, nickel, niobium, niobium carbide and trace boron element. By sequentially implementing austenitizing, quenching, deformation heat treatment, multi-stage subzero treatment, pulsed magnetic field assisted tempering, gradient surface hardening and nano-precipitation regulation treatment, the hardness and toughness of the die steel are remarkably improved. Particularly, through the synergistic effect of multiple advanced heat treatment means, the martensite structure is effectively refined, carbide precipitation is strengthened, the surface hardness and the core toughness are improved, the comprehensive performance of toughness and toughness is achieved, and the method is suitable for the field of high-performance injection molds and hot-working molds.

Low density hot rolled steel has the following properties: 0.12%≦carbon≦0.25%, 3%≦manganese≦10%, 3.5%≦aluminum≦6.5%, 0%≦phosphorus≦0.1%, 0%≦sulfur≦0.03%, 0%≦nitrogen≦0.1%, 0%≦silicon≦2%, 0.01%≦niobium≦0.03%, 0.01%≦titanium≦0.2%, 0%≦molybdenum≦0.5%, 0%≦chromium≦0.6%, 0.01 %≦Copper≦2.0%, 0.01%≦Nickel≦3.0%, 0%≦Calcium≦0.005%, 0%≦Boron≦0.01%, 0%≦Magnesium≦0.005%, 0%≦Zirconium≦0.005%, 0%≦Cerium≦0.1%, and the remainder is iron and unavoidable impurities. The steel plate is 60%~80% ferrite, 10%~35% kappa carbide (Fe,Mn) 3 AlC x (wherein x is 1 or less) and a microstructure containing 0% to 10% austenite, more than 45% of the grains of the microstructure should have a nanohardness of less than 4 GPa and less than 10% of the grains of the microstructure should have a nanohardness of more than 5 GPa.

The present invention provides an ultrahigh-strength cold rolled steel sheet having a tensile strength of 1,100 MPa or more and excellent hydrogen embrittlement resistance, and a manufacturing method therefor. According to one embodiment of the present invention, the ultrahigh-strength cold rolled steel sheet having excellent hydrogen embrittlement resistance comprises, by wt%, 0.1-0.5% of carbon (C), 0.01-2.0% of silicon (Si), 0.1-5.0% of manganese (Mn), 0.01-2.0% of aluminum (Al), more than 0% and less than or equal to 3.0% of chromium (Cr), more than 0% and less than or equal to 1.0% of molybdenum (Mo), more than 0% and less than or equal to 0.4% of nickel (Ni), 0.05-0.4% of copper (Cu), 0.01-0.2% of titanium (Ti), 0.01-0.1% of niobium (Nb), 0.01-1.0% of vanadium (V), 0.001-0.005% of boron (B), more than 0% and less than or equal to 0.02% of phosphorus (P), more than 0% and less than or equal to 0.01% of sulfur (S), and the balance of iron (Fe) and other inevitable impurities, and satisfies a tensile strength (TS) of at least 1,100 MPa, an elongation (EL) of at least 3% and a hydrogen embrittlement test non-fracture time of at least 100 hours.

The invention relates to the technical field of brake disc production, in particular to a high-toughness alloy brake disc and a preparation method thereof. The high-toughness alloy brake disc comprises the following chemical components in percentage by mass: 0.3 to 1.0 percent of niobium; 0.05 to 0.25 percent of antimony; 0.5 to 1.5 percent of molybdenum; 0.5 to 1.5 percent of copper; 0.1 to 0.4 percent of tin; 0.05 to 0.2 percent of titanium; boron: 0.002 to 0.008%; 0.05 to 0.1 percent of lanthanum; 0.03 to 0.08% of neodymium; 0.03 to 0.15% of cerium; and the balance is a gray iron matrix. Through niobium-antimony-molybdenum-boron composite microalloying, triple inoculation and graded annealing processes and in combination with PEO coating and laser microstructure surface treatment, high impact resistance, salt spray corrosion resistance and excellent thermal conductivity in the environment of-40 DEG C to 600 DEG C are achieved.

A hot rolled steel sheet having a composition comprising of the following elements,0.02 % ≤ Carbon ≤ 0.06 %, 1.1 % ≤ Manganese ≤ 1.60%,0.01% ≤ Aluminum ≤ 0.08 %, 0.01% ≤ Niobium ≤ 0.07%, 0.05 % ≤ Titanium ≤ 0.15%, 0.0005% ≤ Calcium ≤ 0.005%, 0% ≤ Phosphorus ≤ 0.03 %, 0 % ≤ Sulfur ≤ 0.015 %, 0 % ≤ Nitrogen ≤ 0.02%,and can contain one or more of the following optional elements 0.001% ≤ Silicon ≤ 0.09%, 0% ≤ Chromium ≤ 0.2%, 0 ≤ Copper ≤ 0.25%, 0% ≤ Nickel ≤ 0.2%,0% ≤ Vanadium ≤ 0.1%, 0 % ≤ Boron ≤ 0.003%, 0 % ≤ Magnesium ≤ 0.010%, 0% ≤ Cerium≤ 0.1%, 0% ≤ Zirconium ≤ 0.010%,the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel sheet comprising in area fraction, 35% to 75% Bainite, 25% to 65% ferrite, from 0% to 2% Pearlite and Martensite­Residual Islands from 0% to 2% wherein said hot rolled steel sheet has an inclusion density of 200 inclusions per square micro­meter, the inclusions having size of 2 microns or more being 25% or less of the total number of inclusions.

The purpose of the present invention is to provide: a high-strength steel sheet and a high-strength plated steel sheet of 1180 MPa or more, both having excellent elongation flange properties, bendability, and resistance to interplate cracking of the heat affected zones of spot weld sections, and allowing the production of components with high dimensional accuracy; methods for manufacturing the same; and a member.　This high-strength steel plate has a prescribed component composition, has a steel structure in which: the effective Ti molar fraction (xTi, eff), as determined from XTi, eff = XTi - XN - XS (where, XTi, XN, and XS are the molar fractions of respective elements in steel) is 0.001 or more; at a position 1 / 4 the plate thickness, the area ratio of martensite is 60% to 99% inclusive; and the area ratio of ferrite and / or the volume ratio of retained austenite in total is more than 0% but no more than 40%. At the grain boundaries of former austenite with a directional difference of 15 degrees or more, the concentration of boron atoms is 0.3 at% to 6.0 at% inclusive, and the number density of precipitates with a size of 2 μm or more is 150 or less per mm2.

The utility model provides a quantitative borax supplementing device for a boron coating tank, which is characterized in that a borax box is arranged above the boron coating tank and is filled with borax, a feeding valve is arranged at the bottom of the borax box, the feeding valve is connected with a feeding pipe, one end of the feeding pipe is provided with a driving device, and the other end of the feeding pipe is connected with the boron coating tank; a material pushing plate is mounted at one end, extending into the feeding pipe, of the driving device, and the material pushing plate is controlled by the driving device to reciprocate in the feeding pipe; the borax supplementing device can replace manual work to supplement borax to the boron coating groove in a timed and quantitative mode, the concentration of the borax in the boron coating groove is guaranteed, the labor intensity of manual supplementing is reduced, and meanwhile compared with manual supplementing, the amount of the supplemented borax can be accurately controlled.

The invention discloses low-boron refining slag which comprises the following raw materials in parts by weight: 45-65 parts of calcium oxide, 11-16 parts of fluorite powder, 2-10 parts of a fluxing agent, 1-3 parts of silicon dioxide and 4-12 parts of an accelerant. The refining slag comprises the following chemical components: 45 to 60 percent of CaO, 10 to 15 percent of CaF2, 5 to 15 percent of Al2O3, 2 to 5 percent of SiO2, 5 to 9 percent of MgO, 3 to 12 percent of Ce2O3 and the balance of unavoidable impurities. Due to the adoption of the technical scheme, compared with the prior art, the refining slag has the advantages of low melting point, good fluidity, capability of well adsorbing inclusions, reduction of the boron content of steel, reduction of smelting energy consumption, low cost and the like.

The invention discloses a preparation method of high-silicon high-hematite limonite pellets, and belongs to the field of blast furnace burden, and the preparation method specifically comprises the following steps: step A, carrying out primary batching, drying and wet grinding on concentrate powder, Kara concentrate powder, Brazil concentrate powder, laterite-nickel ore, red mud iron powder and boron-magnesium concentrate powder in proportion; step B, proportionally adding bentonite into the wet-ground material in the step A, and carrying out secondary batching; step C, conveying the materials in the step B into a vertical mixer for strong mixing; step D, conveying the mixed material to a pelletizing chamber for pelletizing; and E, the green pellets are conveyed to a roasting cooling system to be prepared into finished pellets. According to the pellet prepared through the method, the adding amount of bentonite is reduced, the cost is reduced, the compressive strength of the finished pellet can reach 2500N / P or above, the green pellet drop strength, the compressive strength and the dry pellet compressive strength are far higher than those of on-site pellets, and the production requirement can be met.

The invention provides an improved high-toughness M2 high-speed steel flux-cored wire and a preparation method thereof.The flux-cored wire comprises an outer skin and a flux core, and deposited metal of the flux-cored wire comprises, by weight, 0.5%-1.6% of boron, 0.5%-1.6% of molybdenum, 0.5%-1.6% of molybdenum, 0.5%-1.6% of molybdenum, 0.5%-1.6% of molybdenum, and the balance iron and inevitable impurities. 0.6 to 1.3 percent of carbon; 1 to 1.6% of silicon; 0.3%-0.9% of manganese; 1-2.2% of vanadium; 0.3 to 0.7 percent of nickel; 0.3 to 0.7 percent of cobalt; 3-8% of chromium; 1.5%-2.2% of niobium; 5% of molybdenum; 6% of tungsten; and the balance of iron. The preparation method comprises the steps that all the components of the flux core are sequentially added into a drying machine and then put into a three-dimensional motion mixing machine to be fully and evenly mixed, then the mixture is put into a heat preservation box to be subjected to heat preservation, and obtained flux core powder is reserved for use; rolling the outer skin into a U-shaped groove; flux core powder is added into the U-shaped groove, a forming machine rolls and closes the U-shaped groove and draws the U-shaped groove, and the flux-cored wire is obtained; the flux-cored wire has the characteristics of high toughness and high wear resistance, and compared with plasma and laser cladding powder materials with the same performance, the flux-cored wire is lower in production cost and more beneficial to industrial production.

The invention relates to a control method for increasing the boron content in a forge piece through double-vacuum smelting of 2.25 Cr1Mo0.25 V steel, belongs to the technical field of smelting, and solves at least one of the problems that in an existing 2.25 Cr1Mo0.25 V steel smelting process, the boron content cannot reach the effective effect content, the boron content fluctuation between heat times is large, and an existing boron control process is incompatible with a 2.25 Cr1Mo0.25 V steel double-vacuum process. A control method for improving the boron content in a forge piece through double vacuum smelting of 2.25 Cr1Mo0.25 V steel comprises the steps that vacuum carbon deoxidation refining is conducted, specifically, slagging, diffusion deoxidation, alloying, vacuum treatment, component fine adjustment and soft blowing are conducted on molten steel, and key element adding is conducted; and the vacuum casting comprises preparation before casting and vacuum casting protection. According to the method, the effective boron content is increased, the boron content fluctuation among the heats is reduced, and the process compatibility is good.

A hot rolled steel sheet having a composition comprising of the following elements 0.03% ≤ Carbon ≤ 0.070 %, 0.4 % ≤ Manganese ≤ 0.9%, 0.01% ≤ Aluminum ≤ 0.08 %, 0.01% ≤ Niobium ≤ 0.08%, 0.05 % ≤ Titanium ≤ 0.15%, 0.0005% ≤ Calcium ≤ 0.005%, 0% ≤ Phosphorus ≤ 0.03 %, 0 % ≤ Sulfur ≤ 0.015 %, 0 % ≤ Nitrogen ≤ 0.02%, 0.001% ≤ Silicon ≤ 0.09%,0% ≤ Chromium ≤ 0.2%, 0.% ≤ Copper ≤ 0.25%, 0% ≤ Nickel ≤ 0.2%, 0% ≤ Molybdenum ≤ 0.2%, 0% ≤ Vanadium ≤ 0.1%, 0 % ≤ Boron ≤ 0.003%, 0 % ≤ Magnesium ≤ 0.010%, 0% ≤ Cerium≤ 0.1%,0% ≤ Zirconium ≤ 0.010%, the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of said steel sheet comprising in area fraction, 35% to 70% Bainite, 30% to 60% Ferrite, Pearlite from 1% to 5% wherein the said hot rolled steel sheet has an inclusion density of 110 inclusions per square micro-meter and the inclusions having a size of 2 microns or more being 22% or less of the total number of inclusions.

The invention discloses an ultrahigh-strength metal powder core type flux-cored wire and a preparation method thereof, the ultrahigh-strength metal powder core type flux-cored wire comprises a steel strip and a flux core, the steel strip is filled with the flux core, and the flux core comprises 0.03%-0.10% of carbon, 0.3%-1.0% of silicon, 1.0%-3.0% of manganese, 2.6%-3.0% of nickel, 0.5%-1.0% of molybdenum, 0.3%-1.0% of chromium, 0.1%-0.4% of copper, 0.001%-0.020% of boron, 0.03%-0.07% of titanium, 0.05%-1.0% of magnesium, 0.3%-0.6% of aluminum, 1.2%-3.0% of calcium silicate, 0.3%-0.8% of strontium carbonate, 0.3%-0.8% of lanthanum carbonate, and the balance iron. 0.5 to 1.5 percent of sodium fluoride, 0.08 to 1.0 percent of modified titanium dioxide and the balance of Fe and other impurities. The invention belongs to the technical field of welding materials, and the welding wire has the characteristics that all components of the welding wire are fully matched, the melt fluidity is good in the welding process, filling is good, air holes are few, the high welding flux reaction rate is high, and the wire feeding rate is high.

The invention provides a preparation method of a large-size fine-grain bar, which comprises the following steps: S1, weighing metal Cr, Ni, Mo, Al, W, Co, Ti, Zr, graphite C and nickel-boron raw materials, adding the raw materials into a smelting furnace, smelting, vacuumizing, refining and pouring after the raw materials are molten to obtain an electrode bar, then the electrode bar is sequentially subjected to electroslag remelting and vacuum consumable remelting, and a consumable ingot is obtained; s2, the alloy ingot is subjected to high-temperature homogenization diffusion annealing, and a low-segregation cast ingot is obtained; s3, the cast ingot is heated before forging, and then a bar billet is obtained through forging; and S4, the bar blank is turned to obtain the fine-grain bar with the final specification. According to the method, the fine grain forging process of upsetting and drawing cogging and drawing is adopted, metallurgical defects such as black spots and white spots are not found on the obtained bar in a low magnification mode, abnormal inclusion aggregation is avoided, obvious harmful TCP phase precipitation is not found through microscopic structure analysis of the obtained bar, the structure is uniform, and the grain size is larger than 8 grades.

The invention is suitable for the technical field of mineral powder crushing, and provides a wear-resistant long-life high-pressure roller sleeve for crushing sintered pellet mineral powder, the outer surface of the roller sleeve is surrounded by hard alloy column nails, and wear-resistant nails are inlaid; the hard alloy column nails in the middle area of the non-roller face of the roller sleeve are formed by sintering WC cobalt-based alloy containing nanoscale WC or / and Ti C with the volume ratio being 5-10% and a proper amount of rare earth yttrium or / and cerium. The wear resistance of the hard alloy column nails on the two side areas of the roller surface of the roller sleeve is lower than that of the middle part, or the extension height is 1-3mm lower than that of the middle part; nickel-chromium-boron-silicon-based alloy containing more than 60% of WC is overlaid on the two end surfaces of the roller sleeve; the roller sleeve and the roller shaft are assembled in an interference fit mode through multi-stage stepped shaft holes. The abrasion loss of the hard alloy in the length direction under the unit crushing amount can be greatly reduced, the flatness of the column nails on the roller surface is kept for a long time, the stability of the extending length of the column nails is kept, the roller surface deep pits formed due to foreign matter entering are resisted, the edge of the roller sleeve is prevented from collapsing, and the roller sleeve is convenient to replace and install.

The invention belongs to the technical field of metallurgical manufacturing, and particularly relates to boron microalloyed high-strength free-cutting steel and a production method thereof. The steel comprises the following chemical components in percentage by weight: 0.35%-0.45% of C, 0.10%-0.25% of Si, 1.0%-1.50% of Mn, 0.050%-0.060% of P, 0.20%-0.35% of S, 0.0005%-0.0030% of B, 0.05%-0.20% of Bi, 0.02%-0.06% of Ti, less than or equal to 0.20% of Cr, less than or equal to 0.20% of Cu, less than or equal to 0.005% of N and the balance of Fe and inevitable impurities, wherein Ti / N is greater than or equal to 3.5. The whole-flow process control of converter-LF refining-continuous casting-controlled rolling and controlled cooling is adopted. The free-cutting round steel with the tensile strength reaching 800-1000 MPa is successfully produced, the cutting force is reduced by 20%-30%, and the service life of a cutter is prolonged by 40% or above.

The application relates to the technical field of bearing steel, in particular to a boronized bearing steel and a preparation method thereof. The boronized bearing steel comprises a base body and a boronized layer; the base body is 20CrNiMo steel and comprises the following components in percentage by weight: C 0.18-0.22wt%, Si 0.25-0.32wt%, Mn 0.75-0.83wt%, Cr 0.48-0.55wt%, Ni 0.50-0.70wt%, Mo 0.40-0.50wt%, V 0.18-0.21wt%, and the balance is Fe and inevitable impurities; the boronized layer is obtained through salt bath boronizing, the boronizing agent for the salt bath boronizing is mainly composed of Na2B4O7, Al and KCl, and the thickness of the boronized layer is 20-80 mu m. The application forms a boronized layer with a certain thickness on the surface of the base body through specific base body components and boronizing agents, and the surface hardness, wear resistance, strength and toughness of the bearing steel are significantly improved.

The invention relates to the technical field of hard alloys, and particularly discloses a ruthenium boride reinforced ultra-ultra coarse grain WC-Co hard alloy and a preparation method thereof in order to solve the problems of low strength and hardness and poor toughness of an ultra-ultra coarse grain alloy product caused by difficult control of grain size in an existing ultra-ultra coarse grain alloy preparation process. The ultra-coarse grain WC-Co hard alloy comprises the following raw materials: 0.5-5% of ruthenium-boron mixed powder, 5-10% of cobalt powder and the balance of tungsten carbide particles. Wherein the number ratio of ruthenium atoms to boron atoms in the ruthenium-boron mixed powder is 1: (0.5-1.5), and the carbon adjusting range of the total mass of tungsten and carbon in the tungsten carbide particles is 6.08-6.20 wt%. The problems that WC particles are excessively crushed and Co phases are non-uniformly distributed are solved by utilizing high-energy stirring dry mixing without adding a grinding body and combining a flexible wet grinding process with extremely short time and extremely low ball-to-material ratio, and Ru powder and B powder are introduced and combined with a special sintering process, so that the effects of high toughness, high hardness, high heat conductivity and the like of the ultra-coarse grain alloy are achieved.