39results about How to "Lower brittle transition temperature" patented technology

The invention relates to a high-strength steel plate for a Q500GJE quenched and tempered building structure. The high-strength steel plate comprises the following chemical components: less than or equal to 0.14% of C, 0.20%-0.50% of Si, 1.10%-1.60% of Mn, less than or equal to 0.015% of P, less than or equal to 0.005% of S, less than or equal to 0.20% of Cr, less than or equal to 0.30% of Mo, lessthan or equal to 0.90% of Ni+Mo, less than or equal to 0.30% of Cu, 0.02%-0.04% of Al, less than or equal to 0.20% of V+Nb+Ti, less than or equal to 0.006% of N, and the balance of Fe and inevitableimpurity elements, wherein the carbon equivalent is less than or equal to 0.52%. The yield strength is 545-585 MPa, the tensile strength is 670-715 MPa, and the elongation is larger than or equal to 18.5%. A high-strength steel product for a building, with the yielding-to-tensile ratio less than or equal to 0.84, and the V-type impact energy higher than or equal to 110 J at -40 DEG C, is of a ferrite+pearlite+bainite structure, and the grain size is 8.5 levels or above. The comprehensive performance can completely meet GB/T 19879-2015 and the clients' requirements of steel plates for high-risebuildings.

The invention belongs to the technical field of steel smelting, and relates to a double-phase stainless steel smelting technology. According to the technology, a carbon steel material head, a stainless steel material head, stainless steel cuttings and high carbon ferro-chrome are adopted to serve as raw materials, high-chromium high-carbon molten steel is smelted through an intermediate frequency furnace, and relatively-high-cost low-carbon or micro-carbon chromium iron is not required to be adopted for smelting; after the temperature is proper, the molten steel is transferred into an AOD furnace from a steel ladle; smelting devices like the AOD furnace is adopted for conducting oxygen blowing, decarbonization and molten steel refining, and nitrogen is blown to the steel for increasing nitrogen to the steel; the cost generated by adopting nitralloy for nitrogen adding is reduced, and after the components are qualified, the steel is cast into an electrode blank; when electric slag is remelted, argon or dry air is adopted for protection, and the suction amount of a furnace hearth is further reduced; and the voltage and the current are adjusted to control the melting rate. The double-phase stainless steel smelting technology is also suitable for other applicable fields.

The invention relates to a ferritic stainless steel for tubular heat exchangers and a manufacturing method thereof. The ferritic stainless steel comprises the following chemical components in percentage by weight: at most 0.015% of C, at most 0.020% of N, at most 0.5% of Si, at most 0.5% of Mn, at most 0.035% of P, at most 0.01% of S, 22-24% of Cr, 1.5-3.0% of Mo, 0.0050-0.050% of Al, and the balance of Fe and inevitable impurities, wherein 10(C+N)<=(Nb+Ti)<=0.6%. The manufacturing method comprises the following steps: smelting by an arc furnace+AOD (argon oxygen decarburization)+VOD (vacuum oxygen decarburization) three-step process, carrying out continuous casting to obtain a continuous casting blank, and carrying out hot rolling, acid washing, cold rolling, annealing, acid washing and the like to obtain the high-weldability cold-rolled stainless steel sheet strip. The high-weldability cold-rolled stainless steel sheet strip is suitable for manufacturing welded tubes with higher requirements for corrosion resistance and flaring performance; and the flaring ratio is up to higher than 35%.

A P110 steel level high frequency straight welded pipe manufacturing method comprises (1) taking hot-rolled coil as raw material; (2) shaping the coil into a straight seam pipe by continuous shaping techniques, welding the straight seam on the pipe by a high frequency inductive welding machine to produce a primary pipe, and after the welding, timely removing external and internal burrs of the primary pipe; (3) heating the primary pipe removed of burrs by a medium frequency induction furnace to 920-950 degrees centigrade and conveying it to a hot rolling and diameter reducing machine, rolling the primary pipe into pipe blanks with different apertures by hot mechanical rolling; (4) conducting whole-pipe quenching and tempering to the hot roller pipe blank to produce finished pipe; (5) conducting ultrasonic flaw detection and pipe end magnetic powder inspection to the finished pipe. The invention takes low steel level coil as raw material to produce primary pipe, produces pipe blanks with different diameter specifications by the primary pipe with the same specification, and produces oil casing product with high steel level and high performance by low steel level economical pipe blanks. The working efficiency is high. The production cost is low.

The invention provides a flux-cored wire for 620 MPa-level low-temperature steel. The flux-cored wire for 620 MPa-level low-temperature steel comprises carbon steel skin and a flux core arranged in the carbon steel skin. The flux core comprises the following raw material components, by mass percent, 36%-42% of rutile, 2%-5% of ferromolybdenum, 2%-4% of zircon sand, 15%-20% of electrolytic manganese, 5%-6% of calcium fluoride, 1.5%-3% of an aluminum magnesium alloy, 10%-12% of silicon iron, 3%-5% of ferrotitanium, 1.5%-3% of potassium fluoborate, 9%-10% of nickel powder and the balance ferrous powder and unavoidable impurities. The flux-cored wire for the 620 MPa-level low-temperature steel utilizes CO2 protective gas for welding and has excellent welding process performance and comprehensive performance of deposited metal and a welded joint. The yield strength is larger than or equal to 540 MPa, the extension strength is larger than or equal to 620 MPa, the elongation is larger than or equal to 20%, and under the condition of -60 DEG C, Akv is larger than or equal to 54 J.

The invention relates to hot-rolling H-shaped steel containing and vanadium boride and having excellent low-temperature impacttoughness and a preparation method of the hot-rolling H-shaped steel. The H-shaped steel comprises the following chemical components in percentage by weight(%): 0.10-0.20 percent of C, 0.20-0.35 percent of Si, 1.10-1.45 percent of Mn, not more than 0.020 percent of P, not more than 0.010 percent of S, not more than 0.010 percent of Ca, 0.0005-0.0040 percent of B, 0.02-0.08 percent of V and the balance of Fe and trace amount of impurities. In the smelting process, the mass percentage of gas in a beamblank is that [N] is controlled to be not more than 80ppm and [O] is controlled to be not more than 100ppm. In the rolling process, the heating temperature of the beam blank is 1,190-1,290DEG C, the cogging temperature is 1,120-1,230DEG C and the finish rolling temperature is not more than 850DEG C. In the universal rolling process, the stay time is 15-50s and the accumulative compression ratio is 55 percent or greater. According to the hot-rolling H-shaped steel disclosed by the invention, the low-temperature impacttoughness of Q345 H-shaped steel products can be greatly improved and the low-temperature impacttoughness is better stabilized, so that the quality of the products is ensured and the products are suitable for harsh environments more easily.

The invention relates to a nodular cast iron gear box with high impact toughness at ultralow temperature. The nodular cast iron gear box comprises, by mass, 3.50-3.80% of C, 1.7-1.9% of Si, 0.10-0.15% of Mn, 0.035% or less of P, 0.015% or less of S, 1.0-1.3% of Ni, and the balance of Fe and inevitable impurities. A making method comprises the following steps: melting highly pure Q10 pig iron, Q235 carbon structural iron and returns in an intermediate frequency induction electric furnace, adding nickel plates, and adjusting the percentages of all chemical components; nodulizing by adopting an exposure ladle pour-over technology, and sequentially packing a nodulizing agent, an inoculant and a covering agent in a layered manner; and carrying out primary stream inoculation during tapping, carrying out ladle inoculation, and carrying out secondary stream inoculation during casting. The making method improves the elongation and the low-temperature impact toughness, reinforces the matrix structure, guarantees reasonable graphite sphere number and high nodulizing rate, improves the toughness and plasticity, does not need graphitization annealing heat treatment, and saves the production cost.

The invention discloses a method for producing 380MPa-grade wheel steel and belongs to the technical field of materials. According to the technical scheme, the method for producing the 380MPa-grade wheel steel comprises the following technological steps that plate blank heating, high-pressure water dephosphorization, rough rolling, coiling through a hot coil box, finish rolling, laminar cooling and curling through a curling machine are conducted on a billet, and then the 380MPa-grade wheel steel is obtained. The billet comprises, by mass, 0.06%-0.10% of C, equal to or less than 0.10% of Si, 0.80%-1.10% of Mn, equal to or less than 0.020% of P, equal to or less than 0.010% of S, 0.010%-0.030% of Ti, 0.015%-0.050% of Als and the balance Fe and inevitable impurities. Ti is added into an original C-Mn strengthening system, and thus the strength and the weldability of the wheel steel are improved. Through the design of low-carbon and low-silicon components and reasonable adding of the Als, free N in the steel can be controlled, and the comprehensive performance of the wheel steel is improved.

The invention discloses a 00Cr18Mo2 stainless steel pipe billet and a manufacture method thereof, which belong to the technical field of stainless steel materials. The 00Cr18Mo2 stainless steel pipe billet comprises the following components: 0.01-0.025wt% of C, 0.15-0.35wt% of Si, 0.22-0.45wt% of Mn, 0.023-0.030wt% of P, 0.002-0.015wt% of S, 18.00-19.50wt% of Cr, 1.70-2.50wt% of Mo and the balance of Fe. The 00Cr18Mo2 stainless steel pipe billet has the advantages of excellent corrosion resistance, low brittle transition temperature and good adaptability and can be applied to a generator set cooled by sea water, and resource is saved. Because the provided manufacture method has few technical steps, energy can be saved because the 00Cr18Mo2 stainless steel pipe billet does not need to be heated by electricity energy for multiple times. The manufacture method is favorable for the content of O2, N and C so as to control the content of harmful chemical elements. The non-metal inclusion in the obtained pipe billet can reach B-class 0.5 grade, C-class 0.5 grade, D-class 1 grade and DS class 1 grade. The yield rate is above 89%.

The invention belongs to the technical field of metal material manufacture and particularly relates to a high-strength alloy steel plate for a pressure vessel and a preparation method thereof. The high-strength alloy steel plate for the pressure vessel comprises the following components by weight percentage: 0.20-0.25% of carbon, 0.20-0.40% of silicon, 1.35-1.60% of manganese, less than or equal to 0.018% of phosphorus, less than or equal to 0.008% of sulphur, 0.14-0.18% of vanadium, 0.40-0.70% of nickel and the balance of iron and unavoidable impurities. The high-strength alloy steel plate for the pressure vessel is high in strength and tenacity, low in yield ratio and good in welding performance and can be widely used in the pressure vessel manufacture.

The invention provides a formula of a welding rod coating. The formula consists of marbles, quartz, ferrosilicon, ferromanganese iron, calcium carbonate, potassium carbonate, sodium silicate, starch, aluminum oxide, cryolite and sodium silicate. The formula has the beneficial effects that: the problem that a welding seam is liable to corrode after a welding rod is used for welding is solved, tensile strength and impact toughness of a welding seam are strengthened, a brittle transition temperature of the welding seam is reduced, thermal hardness of the welding seam is improved, and surface hardness of the welding seam is strengthened. Moreover, the formula is low in production cost, simple in manufacturing process, wide in scope of application and easy to popularize.

The invention discloses an air blower and a preparation technique thereof, and belongs to the technical field of metal materials. The air blower comprises 0.5-1.5% of Li, 0.1-0.3% of Pt, 0.1-0.3% of Ir, 2-4% of Ni, 0.5-1.5% of Mg, 1-5% of Cu, and the balance Al and impurities. The chemical activity of Li of the raw materials is high and can react with gas elements such as hydrogen, oxygen, sulfurand nitrogen in alloy to generate a chemical compound with a low density and a low melting point, and bubbles and other defects of metal are eliminated. Pt and Ir are likely to form a Pt-Ir binary alloy phase, the expansion coefficient is small, and thus the capacity to resist thermal expansion and cold contraction of aluminum alloy can be improved. Meanwhile, grains are refined through solid solution treatment and aging treatment, so that the alloy has a good mechanical property. A uniform and compact ceramic-like film is formed on the surface of a product through micro-arc oxidation, and thus the product has extremely high resistance in complex and changeable environments.

The invention discloses medium-chromium molybdenum-free ferritic stainless steel extremely low in brittle transition temperature and a preparation method thereof. The medium-chromium molybdenum-free ferritic stainless steel comprises, by mass percentage, 0.005-0.015% of C, 0.005-0.015% of N, less than or equal to 0.5% of Si, less than or equal to 0.2% of Mn, less than or equal to 0.03% of P, less than or equal to 0.01% of S, less than or equal to 0.005% of O, 18-22% of Cr, 0.08-0.18% of Nb, 0.05-0.1% of Ti, 0.2-0.4% of Ni, 0.1-0.2% of Al, 0.3-0.5% of Cu and the balance iron and inevitable impurities, wherein the brittle transition temperature ranges from minus 120 DEG C to minus 100 DEG C. The preparation method comprises the steps of 1, conducting smelting and pouring in a vacuum induction smelting furnace; 2, heating the materials to 1000-1200 DEG C, preserving the temperature for 60-150 minutes, and then conducting hot rolling, wherein the accumulative reduction amount is 96-98%; and 3, heating the materials to 850-950 DEG C, and preserving the temperature for 6-8 minutes. By means of the method, the service life of the medium-chromium molybdenum-free ferritic stainless steel in a severe service environment such as the low temperature environment is prolonged, and safety of the medium-chromium molybdenum-free ferritic stainless steel is improved; steel production cost is lowered; and the targets that in stainless steel production, resources are saved, energy is saved, emission is reduced, and environmental pollution is prevented are finally achieved.

The invention discloses medium carbon ferromanganese medium-thick steel for 800MPa engineering machinery and a manufacturing method of the medium carbon ferromanganese medium-thick steel, and relatesto the technical field of iron and steel smelting. The medium carbon ferromanganese medium-thick steel comprises the chemical components in percentage by mass of 0.05%-0.08% of C, 4.8%-5.8% of Mn, 0.10%-0.35% of Si, P being smaller than or equal to 0.010%, S being smaller than or equal to 0.003%, 0.01%-0.05% of Ti, 0.7%-1.2% of Ni+Cr+Mo, and balance Fe and inevitable impurities. The medium carbonferromanganese medium-thick steel can have excellent core mechanical properties than common 800MPa high-intensity structural steel, and requirements for extra-high-intensity steel safety performance and low manufacturing cost in the engineering machinery trade under complete adverse environment, can be met.

The invention discloses a low-temperature additive manufacturing wire capable of controlling the grain size as well as preparation and application of the low-temperature additive manufacturing wire. The low-temperature additive manufacturing wire comprises, by mass: 0.03%-0.10% of C, less than or equal to 0.4% of Si, 0.5%-1.5% of Mn, less than or equal to 0.010% of P, less than or equal to 0.005% of S, 0.07%-0.12% of Nb, 1.6%-4.0% of Ni, less than or equal to 0.4% of Mo, 0.01%-0.20% of Cr, less than or equal to 0.02% of V, less than or equal to 0.05% of Al, less than or equal to 0.03% of Cu, 0.006%-0.02% of Ti, less than or equal to 0.005% of B, and the balance Fe. The wire has good impact toughness under different additive manufacturing processes, the change of low-temperature toughness along with temperature is small, and the wire can be used for additive manufacturing of products in the field of oil and gas transportation in a low-temperature environment.

The invention relates to the technical field of low-temperature materials, specifically to a protective rubber sleeve for low-temperature container junction valves. The material of the protective rubber sleeve comprises the following ingredients: butyl rubber, cold-resistant modified natural rubber, fluorinated silicone rubber, a chlorosulfonated polyethylene elastomer, hydroxypropyl methacrylate,carbon black, nano-zinc oxide, stearic acid, a vulcanizing agent, a promoter, a silane coupling agent and an anti-aging agent, wherein the vulcanizing agent used in the ingredients is sulphur; the promoter is one of a promoter TE, a promoter ZIP and a promoter NA-22; and the anti-aging agent is a mixture of an anti-aging agent AW and an anti-aging agent PPD mixed according to the mass ratio of 1:3. The protective rubber sleeve is prepared from a low temperature resistant rubber material. By a new formula for preparation of the low temperature resistant rubber, brittle transition temperature of the material is remarkably reduced.

The invention relates to the technical field of steel pipes, in particular to a high-temperature-resistant seamless steel pipe and a preparation method thereof. The high-temperature-resistant seamless steel pipe comprises the chemical components in percentage by mass: 0.12%-0.22% of C, 0.5%-0.8% of Mn, 0.5%-1.5% of Si, 8%-12% of Cr, 22%-30% of Ni, 0.05%-0.15% of Ti, 0.02%-0.05% of V, 0.05%-0.2% of Cu, 0.18%-0.25% of W, 0.005%-0.02% of Pt, 0.05%-0.1% of Mo, 0.002%-0.01% of Os, 0.005%-0.05% of Nb, 0.005%-0.02% of Re, 0.005%-0.02% of Zr, 0.015%-0.02% of Ta, smaller than or equal to 0.02% of P, smaller than or equal to 0.005% of S and the balance of Fe and inevitable impurities. The seamless steel pipe prepared by the method is excellent in high-temperature resistance and mechanical strength, also has better oxidation resistance and corrosion resistance, the method is simple in production and preparation process and suitable for large-scale production, and the problems of poor high-temperature resistance and mechanical strength and complex preparation process of seamless steel in the prior art are solved.

The invention discloses a robot cover plate and a preparation technology thereof, and belongs to the technical field of metal materials. The raw materials of the cover plate comprise the following components, by weight percentage, 0.1-0.3% of Ba, 0.4-0.6% of Ge, 0.3-0.5% of Zn, 0.04-0.06% of Co, 0.3-0.5% of Fe, 0.6-0.8% of Mn, and the balance Al and impurities. According to the robot cover plate and the preparation technology thereof, the Ge in the raw materials is an important component for improving internal alloy phase flow of an aluminum alloy so that an alloy phase can obtain the best fluidity from hypereutectic to eutectic; in addition, the Ge can also improve the tensile strength, the hardness, the machinability and the high temperature strength of the aluminum alloy; the Mn can eliminate the brittleness-increasing damage of the Fe to the alloy, and the effect of enhancing the mechanical property of the Fe to the aluminum alloy can be maintained; and meanwhile, by means of a mode that a cover plate body and a high polymer layer outside the cover plate body are combined, a product can be endowed with excellent surface corrosion resistance and wear resistance.