1242 results about "Impact toughness" patented technology

The invention relates to the technical field of traffic infrastructure maintenance, and particularly discloses a method for evaluating the anti-collision toughness of a rusted steel bar bridge structure after ship collision, and the method comprises the following steps: firstly, building a rusted bridge pier finite element model based on a rusted steel bar concrete theoretical degradation model; simulating ship collision by adopting an equivalent static method, and determining dynamic damage factors of the ship; structural nonlinear static analysis and nonlinear dynamic analysis are conducted by considering sudden external force to obtain a bridge function loss function, and then a bridge function is calculated; constructing a response surface agent model to perform dynamic response prediction; determining a bridge structure damage state judgment criterion; the vulnerability of the rusted bridge is calculated through Monte Carlo simulation; and according to the bridge function loss function, combining the repair time and the recovery function to calculate a structure anti-collision toughness index. The method provided by the invention fills up the blank of ship collision resistance toughness evaluation of the coastal rusted bridge pier, provides a scientific basis for bridge safety evaluation and maintenance decision, and is of great significance for guaranteeing safe operation of the bridge.

The invention provides a low-temperature-impact-resistant food packaging material and a preparation method and application thereof.The low-temperature-impact-resistant food packaging material is prepared from, by mass, 100 parts of polylactic acid, 1-10 parts of modified layered double hydroxide and 5-40 parts of hyperbranched polyester; wherein the modified layered double hydroxide is obtained by treating layered double hydroxide with a composite anionic surfactant and then treating the treated layered double hydroxide with an organic cationic compound with a long alkyl chain; the composite anionic surfactant comprises a first anionic surfactant and a second anionic surfactant; wherein the first anionic surfactant comprises sodium dodecyl sulfate; the second anionic surfactant comprises a sulfonate anionic surfactant containing an amido bond and a catechol structure. Through the formula design, the impact toughness of the material at low temperature can be improved while the mechanical property of polylactic acid is maintained, and the material can be suitable for the field of food packaging.

The application discloses a kind of thick gauge 430 ferritic stainless steel laser weld low-temperature rollability processing method, comprising: using-1~‑2mm negative defocusing+8~10kW low-power laser welding, the grain of heat-affected zone is refined;NiCr-3 welding wire is preheated to 300~400℃ and carried out hot wire laser welding, reduces cooling rate;Weld is implemented 700 DEG C / 10-12 seconds short time induction annealing, decomposes martensite and releases residual stress;Weld is inducted to ≥50 DEG C before rolling and restores plasticity;Optimize five rack continuous rolling parameter, and the reduction of first rack is reduced to 15%-20%.The application is by welding-heat treatment-rolling whole process synergic control, makes weld low-temperature cracking rate from 2.6 times / month reduce to 1 times below, and-10 DEG C impact toughness is promoted to 22J, cup convexity qualification rate reaches 95%, and annual economic benefit is greatly improved, applicable to the thickness 3.0~8.0mm 430 stainless steel cold rolling production, solves the technical problem that thick gauge 430 stainless steel weld is easy to crack under low-temperature environment.

The invention relates to precipitation-hardening stainless steel and a preparation method and application thereof. The stainless steel comprises the following chemical components: 0.05%-0.25% of C, 0-0.15% of Si, 0.2%-0.5% of Mn, 9%-18% of Cr, 0.2%-5% of Ni, 0.5%-5% of Mo, 0-0.5% of V, 5%-13% of Co and the balance of Fe and inevitable impurities. During preparation, alloy raw materials are forged or rolled after being smelted and cast, or prepared into spherical alloy powder through an atomization method / rotating electrode method and then subjected to 3D printing, a formed component is prepared, and then the product is obtained through aftertreatment. By controlling the proportion of alloy elements and cooperating with an optimized post-treatment process, the dispersion degree and strengthening effect of second-phase precipitation are improved, impact toughness is improved, 3D printing cracking is avoided, excellent comprehensive mechanical properties, especially high-temperature strength, are obtained, the fatigue cracking risk is reduced, the service life is prolonged, and the production cost is reduced. And the corrosion resistance of polishing, machining and complex environments is improved, and the mold can be used in the field of molds.

The invention discloses 15Ni steel for an ultralow-temperature liquid hydrogen storage tank and a preparation method of the 15Ni steel, and belongs to the technical field of metallurgy. The 15Ni steel comprises the following chemical components in percentage by mass: 0.02%-0.07% of C, 0.10%-0.30% of Si, 0.20%-0.80% of Mn, 0.15%-0.30% of Mo, 0.020%-0.050% of Al, 12.5%-15.5% of Ni, 0.0015%-0.0060% of N, less than or equal to 0.008% of P, less than or equal to 0.002% of S, less than or equal to 0.020% of Nb, less than or equal to 0.080% of V, less than or equal to 0.020% of Ti and the balance of Fe and inevitable impurities. The preparation method comprises the procedures of smelting, continuous casting, heating, rolling and heat treatment. The steel plate produced by the invention has excellent ultralow temperature (-269 DEG C) impact toughness, effectively solves the problems of brittle phase martensite precipitation and low strength of stainless steel at a low temperature of-196 DEG C, can replace stainless steel to be widely used for manufacturing large ultralow temperature liquid hydrogen storage tanks, and has wide application prospects.

The invention relates to the technical field of powder metallurgy materials, and discloses rare earth microalloyed ultrahigh-strength high-toughness hot work die steel and a preparation method thereof.The die steel is prepared from 4Cr5MoSiV1 pre-alloyed powder, rare earth hydride, boron carbide and porous amorphous carbon powder loaded with a nickel catalyst. The preparation method comprises the steps of material mixing, sheath packaging, graded dynamic reaction thermal devolatilization, hot isostatic pressing densification and heat treatment, in the graded dynamic reaction thermal devolatilization, active hydrogen generated by decomposition of rare earth hydride is used for reducing oxide on the surface of powder, and nickel catalyzed carbon powder is used for capturing water vapor at low temperature to generate CO to be discharged. An oxide film on the surface of the powder is thoroughly removed through in-situ chemical reaction, original particle boundaries are eliminated, meanwhile, a nano strengthening phase with high thermal stability is generated in situ, and the high-temperature strength, impact toughness and tissue compactness of the die steel are remarkably improved.

The invention discloses a sintered neodymium-iron-boron magnet and a preparation method and application thereof. The magnet comprises main phase crystal particles with RE2Fe14B structures and a grain boundary phase. The grain boundary phase comprises a two-particle grain boundary phase between two main phase crystal particles and a grain boundary triple-phase point composed of more than three main phase crystal particle gaps; the ratio of the number of the main phase crystal particles to the number of grain boundary triphase points is smaller than or equal to 3. According to the sintered neodymium-iron-boron magnet, through proper component design, reasonable control over the (Cu + Ga) / X ratio and control over the thickness of an alloy sheet and the ratio relation between the average width of columnar crystals in the alloy sheet and the granularity of magnetic powder, concentrated distribution of grain boundary three-phase points can be effectively restrained, the grain boundary phase proportion can be increased, grain boundary phase distribution can be optimized, and the performance of the sintered neodymium-iron-boron magnet can be improved. Therefore, both high magnetic performance and high impact toughness are achieved. The sum of the magnetic energy product and the coercive force of the sintered neodymium-iron-boron magnet is larger than or equal to 75, the impact toughness of the sintered neodymium-iron-boron magnet is larger than or equal to 20 kJ / m < 2 >, and the sintered neodymium-iron-boron magnet can be applied to new energy automobile motors, energy-saving

The invention relates to the technical field of metal materials, and discloses steel for a battery shell and a preparation method of the steel. The steel for the battery case comprises the following chemical components in percentage by weight: 0.001%-0.004% of C, 0.01%-0.02% of Si, 0.12%-0.22% of Mn, 0.004%-0.01% of P, less than or equal to 0.004% of S, 0.2%-0.4% of Cr, 0.02%-0.05% of Al, 0.015%-0.035% of Ti, 0.001%-0.003% of B, 0.01%-0.03% of Nb and the balance of Fe and inevitable impurities. By accurately controlling the components in the steel, particularly controlling the C content, the niobium content and the chromium content in a proper range, the yield strength, the tensile strength and the ductility of the steel can be improved, and particularly the low-temperature impact toughness of the steel can be improved.

The invention relates to the field of ferrous metallurgy and forge piece manufacturing, in particular to high-toughness, ultra-pure and large-quenching-depth 40CrNiMoRE rare earth special steel for a large ring piece and a preparation method of the high-toughness, ultra-pure and large-quenching-depth 40CrNiMoRE rare earth special steel. The invention relates to a high-temperature-resistant steel material, which comprises the following chemical components in percentage by weight: 0.3 to 0.5 percent of C, 0.1 to 0.5 percent of Si, 0.4 to 0.8 percent of Mn, 0.5 to 1.5 percent of Cr, 0.5 to 1.5 percent of Ni, 0.1 to 0.5 percent of Mo, 0.05 to 0.30 percent of V, 0.0005 to 0.0030 percent of B, 0.005 to 0.030 percent of RE and the balance of Fe and inevitable impurities. Through V, B and RE comprehensive microalloying, molten steel purification, inclusion modification and grain refinement, the hardenability is improved, and the surface quenching layer depth, hardness uniformity and impact toughness are ensured. And moreover, the high-toughness, ultra-pure and large-quenching-depth large ring piece is obtained through preparation technologies such as pure smelting, airtight protection pouring and uniform deformation, and the technical problems that an existing large ring piece is low in purity, poor in toughness, insufficient in hardenability, cracked in surface quenching and the like can be effectively solved.

The invention discloses a preparation method of a high-impact-toughness super-large-specification Ti80 titanium alloy ring forging, and belongs to the technical field of high-quality titanium alloy materials. The method comprises the following steps: preparing a cast ingot; the prepared cast ingot is subjected to multi-heating-number forging, and a cake blank is obtained; the prepared cake blank is subjected to ring rolling forging, and an annular blank is obtained; and the prepared annular blank is subjected to heat treatment, and the titanium alloy ring forging is obtained. According to the titanium alloy ring forging process adopted by the invention, on the premise of eliminating the longitudinal welding seam, the overall structure uniformity of the pressure-resistant shell can be ensured, and the mechanical property is stable. By designing a reasonable processing route and formulating optimal processing parameters, the uniformity of the material structure is improved, and the manufacturing safety and reliability of the pressure-resistant shell are improved. The method is suitable for preparing the Ti80 titanium alloy ring forge piece with the outer diameter of 4000-10000 mm, the wall thickness of 100-500 mm and the piece weight larger than or equal to 8 t.

The invention relates to the technical field of pipeline steel for oil and gas transmission, in particular to a novel low-C low-Cr corrosion-resistant pipeline steel plate, a preparation method and a pipeline steel pipe, and the novel low-C low-Cr corrosion-resistant pipeline steel plate comprises the following chemical elements: less than or equal to 0.03 wt% of C, less than or equal to 0.025 wt% of Sb, 0.50-1.20 wt% of Al, 0.0005-0.0012 wt% of Mg, 0.0012-0.0042 wt% of Ca, less than or equal to 0.50 wt% of Cr, 0.10-0.30 wt% of Ni, 0.10-0.30 wt% of Si, 1.20-1.80 wt% of Mn, 0.10-0.30 wt% of Mo, 0.02-0.06 wt% of Nb, 0.03-0.08 wt% of V, 0.01-0.03 wt% of Ti, less than or equal The manufactured steel plate is low in manufacturing cost, excellent in yield strength, tensile strength, ductility, impact toughness, corrosion resistance, hydrogen induced cracking resistance and other mechanical properties and suitable for seabed and land oil and gas conveying pipeline engineering in the high Cl <-> and CO2 / H2S corrosion environment.

The invention belongs to the field of novel polyamide composite fiber materials, and particularly discloses a high-toughness polyamide fiber composite material and a preparation method thereof. The composite material is prepared from the following raw materials in parts by weight: 55-75 parts of long-chain polyamide PA610 resin, 10-25 parts of ultra-high molecular weight polyethylene fiber, 8-18 parts of polyether block amide elastomer, 1.5-4 parts of a compound nucleating agent, 0.8-2 parts of a titanate coupling agent and 0.3-1 part of a composite antioxidant. The preparation method is characterized by comprising the following steps: firstly, carrying out surface pretreatment on the ultra-high molecular weight polyethylene fiber by adopting a low-temperature plasma technology so as to improve the interfacial compatibility of the ultra-high molecular weight polyethylene fiber and a resin matrix; and then carrying out melt blending granulation on the pretreated fiber and other raw materials through a twin-screw extruder, wherein the fiber is added from a side feeding port to avoid excessive shearing and breaking. The obtained product has ultrahigh impact toughness, excellent rigidity, excellent low-temperature toughness and heat resistance, and is especially suitable for the fields of manufacturing automobile parts, sports protection equipment and the like with extremely high requirements on toughness and durability.

The invention relates to the field of building materials, and discloses high-toughness and high-energy-absorption polymer emulsion modified mortar and a preparation method thereof, and the mortar is composed of ordinary Portland cement, river sand, a polymer emulsion, water, an active admixture and chopped fibers. Wherein the polymer emulsion is selected from styrene-acrylic emulsion (SBR), ethylene-vinyl acetate (EVA), polyurethane emulsion or a combination thereof; the mixing amount is 5-20wt% of the mass of the cementing material. According to the invention, a viscoelastic network is formed in a cement matrix through the polymer emulsion, and the synergistic effect of the active admixture and the chopped fibers is combined, so that the bonding strength, the crack resistance, the impact resistance and the stress wave dissipation capability of the mortar are remarkably improved. Test results show that the mortar provided by the invention is obviously superior to ordinary mortar in the aspects of 28d breaking strength, impact toughness and stress wave attenuation performance, and is suitable for high-performance constructional engineering and protective engineering.

The invention provides low-carbon steel for a seamless gas cylinder as well as a preparation method and application of the low-carbon steel. The preparation method comprises the steps that S1, raw materials are prepared according to components of the low-carbon steel for the seamless gas cylinder; s2, the raw materials are smelted, and a first steel billet is obtained; heating the first steel billet to obtain a second steel billet; s3, under the conditions that the initial rolling temperature ranges from 1120 DEG C to 1180 DEG C, and the final rolling temperature ranges from 880 DEG C to 980 DEG C, at least eight passes of hot rolling are conducted on the second steel billet, and a hot-rolled steel billet is obtained; s4, cooling the hot-rolled steel billet to obtain a third steel billet; and S5, the third steel billet is subjected to heat treatment, and the low-carbon steel for the seamless gas cylinder is obtained. Alloy element components of the low-carbon steel for the seamless gas cylinder are meticulously designed, meanwhile, a preparation technology is cooperatively matched, the comprehensive mechanical property of the obtained low-carbon steel is optimized, and more importantly, the low-carbon steel shows excellent impact toughness under the low-temperature condition.

The invention provides high-strength wear-resistant backing bearing steel and a heat treatment process thereof, and belongs to the technical field of bearings. According to the process, under the vacuum condition, high-density aluminum oxide is converted into low-density stable dodecacalcium heptaaluminate by utilizing interface diffusion and a phase change mechanism of calcium, and meanwhile, CaF2-CaO-based slag is adopted to optimize the sulfur adsorption capacity and promote floating of inclusions. And by controlling the deoxidation temperature and the reaction time, calcium ions are guaranteed to be fully diffused, and the high-stability inclusion conversion rate is achieved. Harmful inclusions and sulfur and oxygen impurities are effectively reduced, the impact toughness of the material is improved, the fatigue life of the material is prolonged, the anisotropy of the material is improved, and finally the high-quality bearing steel with high strength, high toughness and excellent isotropy is obtained.

The invention discloses a method for improving impact toughness of aluminum-containing ultrahigh-strength steel. The method comprises the following steps: forging an aluminum-containing ultrahigh-strength steel cast ingot; carrying out two-stage hot rolling on the forged ultrahigh-strength steel, and carrying out water cooling treatment after hot rolling; the hot-rolled ultrahigh-strength steel is annealed at the annealing temperature of 800 + / -50 DEG C, heat preservation is conducted for a period of time, furnace cooling is conducted to 600 + / -50 DEG C, and discharging and air cooling are conducted; the ultrahigh-strength steel is subjected to solid solution and aging treatment, the solid solution process comprises the steps that a heat treatment furnace is heated to 950-1000 DEG C for charging, heat preservation is conducted for 30-40 min, then oil cooling is conducted, the aging process comprises the steps that heat preservation is conducted for 55-65 min at the temperature of 500-550 DEG C, and then air cooling is conducted. The technology is scientific and reasonable, the toughness of the aluminum-containing ultrahigh-strength steel is greatly improved while the strength of the ultrahigh-strength steel is guaranteed through the combination of two-stage rolling and the reasonable heat treatment technology, and therefore the service safety of the aluminum-containing ultrahigh-strength steel is improved.

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 relates to a preparation method of bainite steel with high toughness and strength at low temperature, and the strength and toughness of the bainite steel at low temperature are improved by designing process parameters and steel ingot components. The bainite steel with high toughness and strength at low temperature is finally obtained by designing the components of the steel ingot, avoiding the addition of elements such as nickel, molybdenum and vanadium, reducing the material cost and the processing difficulty and accurately controlling the cooling rate of heat treatment. The prepared bainite steel is composed of strip-shaped bainite and thin strip-shaped retained austenite, and the volume fraction of the retained austenite is 5-10%. The tensile strength is not lower than 1240 MPa, the normal-temperature impact is not lower than 120 J, and the impact toughness at-40 DEG C is not lower than 80 J.

The invention discloses a resin binding agent for a resin diamond wire, the resin diamond wire and a preparation method of the resin binding agent, and belongs to the technical field of binding agents for resin diamond wires. Two brand-new modified compounds are designed and synthesized, boron-containing and nitrogen-containing compounds are introduced to form a covalent bond enhanced polyurethane derivative; and the other one is a double-functional-group siloxane oligomer containing an epoxy group and a carboxyl group, which is prepared by carrying out hydrolytic condensation on raw materials such as methyltrimethoxysilane and the like, neutralizing and purifying. The resin binder takes epoxy-phenolic hybrid resin as a main body and is compounded with the two modified compounds, a curing agent, a coupling agent and other components. The resin diamond wire is prepared through wire core pretreatment, glue solution preparation, coating, multi-stage curing and post-treatment. The heat resistance, the bonding strength with diamond and the impact toughness of the bonding agent are remarkably improved, and the bonding agent is suitable for high-precision cutting of hard and brittle materials such as photovoltaic silicon wafers and the like.

The invention relates to the technical field of fiber reinforced composite materials, in particular to a basalt fiber reinforced composite board in a dynamic heavy load environment and a preparation method. The basalt fiber reinforced composite board comprises an upper surface layer, an upper reinforcing layer, a core layer, a lower reinforcing layer and a lower surface layer. According to the invention, rigid nanoparticles and carboxyl-terminated nitrile rubber are introduced to construct a rigid-flexible composite toughening system, and nano aluminum oxide and silicon dioxide are taken as rigid particles and are uniformly dispersed in an epoxy cross-linked network, so that slippage and crack propagation of molecular chains can be effectively hindered, and the rigidity and damage resistance of a matrix are improved; meanwhile, the carboxyl-terminated nitrile rubber is used as reactive liquid rubber, after carboxyl of the carboxyl-terminated nitrile rubber reacts with epoxy groups, the carboxyl-terminated nitrile rubber is distributed in a matrix in a sea-island structure and can serve as stress concentration points, a large amount of crazing and shear bands can be induced, and a large amount of impact energy can be consumed; and the impact toughness is greatly improved while the high strength of the material is maintained.

The preparation method of the A1-grade nondestructive inspection high-impact-toughness TC4 titanium alloy large-size bar comprises the steps that a secondary finished product cast ingot is subjected to a multi-heating-number high-temperature single-phase beta-region large-deformation forging process in the cogging stage, and as-cast grains are fully crushed and refined in the modes of axial upsetting, lateral upsetting, diagonal upsetting and the like; then, high-low-high-low repeated forging is conducted at the temperature above and below the phase transformation point, grain homogenization is achieved through high-temperature dynamic recrystallization, an original grain boundary is eliminated, and deformation dead zones of a corner angle area are effectively reduced in combination with multi-heating-number diagonal drawing-out forging; and finally, multi-heating-number forging is conducted in the two-phase region, a heat treatment process is combined, the microstructure form is further optimized, and a lamellar alpha structure is controlled to guarantee the low-temperature impact performance. According to the method, the structure uniformity of the TC4 alloy bar can be remarkably improved, the A1-level nondestructive testing requirement is met, and the method has excellent axial and chordwise mechanical properties and is suitable for ocean equipment and other high-end application fields with strict requirements for the comprehensive performance of materials.

The invention relates to the technical field of welding materials, in particular to a low-temperature-resistant 5183 aluminum alloy welding wire and a preparation method thereof. The low-temperature-resistant 5183 aluminum alloy welding wire is prepared from the following components in percentage by mass: 0.08 to 0.14 percent of Si, 0.23 to 0.32 percent of Fe, 0.08 to 0.12 percent of Cu, 1.1 to 1.5 percent of Mn, 5.28 to 5.84 percent of Mg, 0.11 to 0.15 percent of Cr, 0.01 percent of Zn, 0.03 to 0.04 percent of Ti, 0.0007 to 0.0009 percent of Be, 0.35 to 0.41 percent of Sc, 0.1 to 0.13 percent of Zr, 0.6 to 0.8 percent of Li and the balance of Al. The proportion of Al to Mg in the aluminum alloy welding wire is precisely regulated and controlled, multi-element microalloying design is adopted, the impact toughness of the welding wire in the ultralow-temperature environment of-196 DEG C is improved, and the strict requirements of low-temperature application scenes are met.

The invention discloses wear-corrosion-resistant high-strength steel for a power transmission tower and a preparation method thereof, and belongs to the technical field of metal materials. The wear-corrosion-resistant high-strength steel for the power transmission tower provided by the invention has good corrosion resistance and wear resistance, has excellent wear resistance in a soil environment of sulfate ions with the concentration of 300 mg / kg-50000 mg / kg and chloride ions with the concentration of 500 mg / kg-10000 mg / kg, and meets various environmental performance requirements of an acid soil environment, an atmospheric corrosion environment and the like. In an acid soil environment, the corrosion resistance is more than 8 times that of plain carbon steel, and the relative corrosion rate is lower than 10%; compared with Q355B, the corrosion rate of atmospheric corrosion resistance is lower than 40%, and the abrasive wear rate is 26.5%-28.0%; and through reasonable matching of corrosion-resistant elements, the requirements of corrosion resistance in various environments are met. The yield strength is 775 MPa-805 MPa, the tensile strength is 952 MPa-985 MPa, the percentage elongation after fracture A50 is larger than or equal to 28%, the low-temperature impact toughness at the temperature of-60 DEG C is larger than or equal to 260 J, meanwhile, the forming performance is excellent, and the 180-degree cold bending requirements that d is equal to 1.0 a are met.

The invention discloses a microalloyed medium-carbon high-speed wheel with good comprehensive mechanical performance and a heat treatment method and a preparation method of the microalloyed medium-carbon high-speed wheel. The microalloyed medium-carbon high-speed wheel comprises, by mass, 0.50%-0.55% of C, 0.30%-0.40% of Si, 0.70%-0.80% of Mn, 0.25%-0.35% of Cr, 0.03%-0.04% of Mo, 0.04%-0.12% of V, smaller than or equal to 0.002% of Ti, smaller than or equal to 0.020% of Al, 0.004%-0.010% of N and the balance Fe and inevitable impurity elements. On the basis that the content of C is not increased, the wheel obtains good toughness matching performance by regulating and controlling the content of Cr, Mo and V elements, and the wheel has high strength, high hardness, high impact toughness and high fracture toughness and has good use safety performance.

The invention discloses a post-forging heat treatment method for improving the structure uniformity of hot-work die steel, which comprises the following steps: (1) returning the forged hot-work die steel to a furnace, supplementing the temperature to 980-1020 DEG C, preserving the heat for 4-6 hours, discharging the hot-work die steel, alternately cooling the hot-work die steel to 150-300 DEG C by water and air, and loading the hot-work die steel into a heating furnace; (2) the temperature is increased to 650-750 DEG C along with the furnace, heat preservation is conducted for 2-4 h, and the mixture is discharged out of the furnace, air-cooled to 150-300 DEG C and loaded into a (3) the temperature is increased to 800-850 DEG C along with the furnace for preheating and heat preservation, and the heat preservation time is 2-4 Raising the temperature to 1020-1050 DEG C, and keeping the temperature for 4-6 hours; and discharging from the furnace, alternately cooling to 150-300 DEG C by water and air, loading into a heating furnace, and carrying out isothermal spheroidizing annealing. According to the method, the forging structure can be refined, the forging coarse grain and mixed crystal defects are eliminated, chain carbide precipitation of the annealing structure is inhibited, and the uniformity of the annealing structure and the transverse core impact toughness of the material can be remarkably improved.

The invention relates to the technical field of high-strength steel plate production, in particular to a high-strength storage tank steel plate with high and low temperature impact toughness and a manufacturing method, and the steel plate comprises the following chemical components: 0.16%-0.18% of C, 0.15%-0.32% of Si, 0.93%-1.14% of Mn, less than or equal to 0.015% of P, less than or equal to 0.01% of S, 0.051%-0.12% of Cr, 0.06%-0.08% of Mo, 0.011%-0.023% of Nb, 0.0049%-0.011% of Ta, 0.020%-0.045% of Alt and the balance of Fe and impurities. By matching with a production process of molten iron spheroidizing inoculation treatment, optimized two-stage rolling and efficient short-time heat treatment, the finished steel plate has high strength, good low-temperature toughness and formability and excellent plate shape; and meanwhile, good structure uniformity and good corrosion resistance are achieved.

Provided is a steel sheet for a CO2 transport line pipe that is suitably provided to a pipeline for transporting a liquid and / or supercritical state CO2. A steel sheet according to the present invention has: a component composition that contains, in mass%, 0.03-0.08% of C, 1.50-2.50% of Mn, 0.030% or less of P, 0.0100% or less of S, 0.0100% or less of N, 0.010-0.200% of Al, 0.10-1.00% of Si, and 0.0005-0.0050% of O, that further contains a prescribed amount of one or more selected from Cu, Ni, Cr, Mo, and W, that exhibits a [Si] / [O] value of 20-900, and in which the remaining portion comprises Fe and unavoidable impurities; a micro structure in which the area ratio of bainite is not less than 90% and the area ratio of island martensite is less than 3%; a strength where the tensile strength is not less than 625 MPa; and a toughness in which the Charpy impact absorption energy at -40°C is not less than 320 J.

This invention discloses a high-strength and high-toughness high-manganese steel plate for ultra-low temperatures and its preparation method. Its chemical composition and mass percentages are: C 0.04–0.10%, Mn 21.0–25.5%, Si 0.25–0.35%, P≤0.008%, S≤0.003%, O≤0.003%, Ti 0.02–0.05%, W 0.01–0.05%, with the balance being Fe and unavoidable impurities. The high-manganese steel plate has a stacking fault energy of 40–45 mJ / m at -196℃. 2 This steel plate achieves its design by controlling the stacking fault energy to 40–45 mJ / m. 2 This ensures that the steel undergoes a strong TWIP effect in the subsequent heavy impact pre-hardening step, forming a gradient nanocrystalline layer on the steel surface, which significantly improves the yield and tensile strength of the steel; it can improve the uniformity of the internal structure of the steel plate and significantly improve the low-temperature impact toughness of high manganese steel, with an impact toughness AKV≥200J at -196℃.

The application discloses a process method for improving toughness of X70 anti-large-deformation pipeline steel, and ideal mechanical properties and organizational morphology are obtained through control of components, continuous casting, heating, rolling, cooling and other processes, finally, the organizational morphology of 70-80% ferrite and hard phase components such as bainite and martensite is obtained, the uniform elongation and toughness of the pipeline steel are improved, the yield strength ratio is low, and the deformation resistance and anti-large-deformation capacity are improved. The X70 anti-large-deformation pipeline steel plate has a Charpy impact toughness of 350 J or more at-20 DEG C, a drop hammer shearing area of 95% or more, a yield strength of 480-550 MPa, a tensile strength of 600-680 MPa, a yield strength ratio of 0.78 or less, a UEL of 12% or more, and a R t1.5 / R t0.5 of 1.15 or more. The product is widely applied to pipeline engineering prone to large plastic deformation such as ground slip deformation in earthquake-prone areas, ground liquefaction settlement caused by permafrost and submarine pipeline laying.

The invention discloses a preparation method of a rare earth microalloyed high manganese steel wear-resistant part, and belongs to the technical field of wear-resistant materials. The preparation method of the rare earth microalloyed high manganese steel wear-resistant part comprises the following steps that C, Mn, Si, Cr, Mo, Y-based heavy rare earth alloy, silicon-aluminum-barium-calcium alloy and Fe are weighed according to the mass percent, and after electric arc furnace smelting and silicon-aluminum-barium-calcium alloy deoxidation pretreatment, secondary rare earth feeding and alloying are adopted, feeding the residual alloy wires into the pouring cup during pouring; and the molten steel is cast after standing, and a casting blank is subjected to water toughening treatment. Through two-stage rare earth feeding, rare earth burning loss is reduced, a uniform strengthening phase is formed, precise process parameters are matched, the problem of obdurability imbalance of traditional high manganese steel is solved, the hardness, impact toughness and wear resistance of a wear-resistant part are improved, the wear-resistant part is suitable for mine crusher hammerheads and excavator bucket teeth, the service life is prolonged, the process is controllable, and the wear-resistant part is suitable for industrial production.