2683 results about "Austenite" patented technology

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2500MPa-grade bridge cable and a manufacturing method of the high-strength complex-phase hot-rolled wire rod, after the high-carbon component of Nb-V-Mo is rolled and spun into a wire rod, the wire rod is subjected to online molten salt tail end quenching toughening treatment, so that the wire rod passes through front-section molten salt and is cooled at a cooling speed of greater than or equal to 38 DEG C / s, a part of austenite structure is transformed into quenched martensite, and a part of austenite structure is transformed into quenched martensite; the method comprises the following steps of: heating to a sorbite phase region temperature through a rear-section molten salt, controlling unconverted austenite to be converted into sorbite, performing isothermal tempering, controlling precipitation and growth of carbides, and finally performing slow cooling through a roller way to prepare a hot-rolled wire rod of which a microscopic structure comprises a complex-phase structure consisting of tempered martensite and tempered sorbite, wherein the tensile strength of the hot-rolled wire rod is 1710-1750MPa; the production method has the advantages that the material cost is controlled, the production efficiency is improved, and the production method is suitable for 2500MPa bridge cable production and is beneficial to reducing the risk of wire breakage in downstream cold drawing and subsequent processing processes.

The invention relates to a hot-rolled wire rod for a 2100MPa-grade bridge cable and a manufacturing method of the hot-rolled wire rod, after the hot-rolled wire rod is formed by rolling high Si-Mn chemical components and spinning at the spinning temperature of more than or equal to 955 DEG C, the wire rod is cooled at the cooling speed of more than or equal to 36 DEG C / s through online molten salt sorbite regulation and control treatment, enters a sorbite phase region from an austenite state, promotes sorbite phase transformation and is subjected to isothermal treatment to remove stress; and finally, roller way slow cooling is conducted, the hot-rolled wire rod with the microscopic structure comprising tempered sorbite with the volume percentage larger than or equal to 95% and the balance being a mixed structure composed of ferrite and fused sorbite is prepared, deteriorated structures such as network carbide and martensite can be effectively controlled, wire rod structure regulation and control, strength and plasticity matching and stable production are achieved, and the effects that the tensile strength is 1500-1540 MPa, the tensile strength is high, and the tensile strength is high can be achieved. The composite material is used in the application fields of manufacturing of 2100MPa-grade ultrahigh-strength bridge cables and the like, and is beneficial to reduction of the risk of wire breakage.

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2200MPa-grade bridge cable and a manufacturing method of the high-strength complex-phase hot-rolled wire rod. After C-Si-Mn-Cr chemical components are rolled and spun into a wire rod, the wire rod is subjected to online molten salt critical quenching isothermal treatment, the wire rod is controlled to be subjected to front-section treatment and cooled at a cooling speed of greater than or equal to 38 DEG C / s, and enters a pearlite and martensite mixed phase region from an austenite state; the method comprises the following steps: firstly, carrying out heat treatment on austenite to promote transformation of part of austenite to sorbite and martensite, then carrying out post-treatment, reducing the circulation volume of molten salt, promoting transformation of austenite to pearlite, carrying out isothermal tempering, and finally carrying out roller way slow cooling, so as to prepare a hot-rolled wire rod of which the microstructure comprises a complex phase structure consisting of tempered pearlite, tempered sorbite, ferrite and tempered martensite, the composition system can be simplified, the deteriorated structure can be effectively controlled, complex-phase structure regulation and control and high-strength plastic performance matching are achieved, the tensile strength is 1568-1603 MPa, the percentage reduction of area is 29%-34%, and stable manufacturing of the bridge cable is facilitated.

The invention relates to the technical field of metal forge piece machining, in particular to an irregular metal forge piece heat treatment method and system.The irregular metal forge piece heat treatment method comprises the steps that firstly, temperature compensation partitions are divided according to geometrical characteristics, and stepped preheating is implemented to establish a uniform basic temperature field; then, the heat preservation time of each subarea is independently regulated and controlled in the austenitizing stage, and sufficient transformation of a thick-wall area structure and control over the grain size of a thin-wall area are both considered; in the quenching process, partition strength adjustment is carried out based on a preset cooling map, and cooling parameters are dynamically optimized through real-time feedback; and finally, according to the residual stress distribution, carrying out partition stepped tempering. The heating and cooling uniformity is remarkably improved through partition dynamic temperature management, and the structure difference and thermal stress concentration caused by section sudden change are effectively inhibited; the microstructure is ensured to be uniform and stable through austenitizing control; the hardenability and the deformation resistance are balanced through a differential cooling strategy; and directional reduction of residual stress is achieved through an intelligent tempering mechanism, and the cracking risk is greatly reduced while the comprehensive mechanical property is improved.

The invention relates to a hot-rolled wire rod for a 2200MPa bridge cable and a manufacturing method of the hot-rolled wire rod, a high-carbon V-containing chemical component design rolling production line is adopted, after the wire rod is spun into the wire rod at the spinning temperature of more than or equal to 920 DEG C, online molten salt rapid cooling isothermal treatment is carried out, the molten salt treatment time is controlled to be less than or equal to 300s, the wire rod is cooled at the cooling speed of more than or equal to 35 DEG C / s, and enters a sorbite phase region from an austenite state; according to the hot-rolled wire rod, a structure with sorbite as the main part is formed and subjected to isothermal weak tempering to remove stress, finally, roller way slow cooling is conducted, the hot-rolled wire rod with the microscopic structure comprising a mixed structure composed of weak tempered sorbite as the main part and ferrite and fused pearlite as the balance is prepared, the tensile strength can reach 1550-1590 MPa, the percentage reduction of area is 31%-36%, the mechanical property same-circle difference is smaller than or equal to 30 MPa, and the hot-rolled wire rod can be used for manufacturing the steel wire rod. The method is used in the application field of manufacturing of 2200MPa-grade ultrahigh-strength bridge cables and the like, the risk of wire breakage is reduced, and the strength grade of the bridge cables is improved.

The invention relates to a hot-rolled wire rod for a 2230 MPa grade stranded wire and a manufacturing method of the hot-rolled wire rod, after a Cr-Nb-Al high-carbon component design is rolled and spun into a wire rod, the wire rod is subjected to online molten salt isothermal toughening treatment, so that the wire rod is firstly subjected to front-section molten salt treatment and enters a sorbite phase region from an austenite state to form a structure taking a sorbite structure as a main structure; and then carrying out rear-section molten salt treatment, reducing the circulation volume of molten salt, promoting the unconverted retained austenite to be continuously converted into sorbite, carrying out isothermal tempering, promoting fusing of a part of sorbite lamellar layers, and finally carrying out slow cooling through a roller way, so as to prepare the hot-rolled wire rod of which the microscopic structure comprises a mixed structure consisting of tempered sorbite, ferrite and fused sorbite, the material cost can be controlled, the tensile strength is 1513-1563 MPa, the percentage reduction of area is 31%-36%, and the structure uniformity and the production efficiency are both considered, so that off-line heat treatment is avoided during stranded wire manufacturing, and the drawing pass and the cracking risk are reduced.

The invention relates to a hot-rolled wire rod for a 2500 MPa bridge cable and a manufacturing method of the hot-rolled wire rod, which are characterized in that after Nb-V-Mo high-carbon component is rolled and spun into a wire rod, the wire rod is cooled at a cooling speed of more than or equal to 33 DEG C / s through online molten salt rapid cooling isothermal treatment, and enters a sorbite phase region from an austenite state to form a structure mainly comprising sorbite and control the precipitation and growth of carbides; the hot-rolled wire rod with a microscopic structure comprising a mixed structure composed of tempered sorbite, ferrite and fused sorbite is prepared through roller way slow cooling, the content of strengthening elements can be increased without weakening the toughness of the material, the material cost is considered, the tensile strength is 1692-1735 MPa, the percentage reduction of area is 25%-30%, and the tensile strength of the steel wire rod is 1692-1735 MPa. The method is used for the application field of manufacturing of 2500 MPa-grade ultrahigh-strength bridge cables and the like, and the wire breaking risk in the drawing and twisting process can be reduced easily.

The invention relates to a hot-rolled wire rod for a 2060MPa-grade stranded wire and a manufacturing method of the hot-rolled wire rod. Mn-Cr high-carbon chemical component design and rolling spinning are performed to form a wire rod, then online molten salt isothermal phase change treatment is performed, the wire rod is firstly subjected to front-section molten salt treatment and enters a sorbite phase region from an austenite state to form a structure taking a sorbite structure as a main structure, and then the wire rod is subjected to rear-section molten salt treatment, so that the hot-rolled wire rod is obtained. The method comprises the following steps of: firstly, carrying out heat treatment on the residual austenite, promoting the unconverted residual austenite to be converted into a sorbite structure, simultaneously promoting isothermal tempering of the structure and fusing of a part of sorbite lamellas, and finally, slowly cooling through a roller way to prepare a hot-rolled wire rod of which a microscopic structure comprises a mixed structure consisting of tempered sorbite, tempered ferrite and fused sorbite, so that the material cost can be controlled; the high-strength and high-plasticity performance matching of the wire rod is improved, the tensile strength is 1370-1420 MPa, the percentage reduction of area is 35%-40%, and the mechanical property fluctuation is reduced, so that the wire breaking risk in stranded wire production is reduced, and efficient and stable production is promoted.

The invention discloses super high-strength and high-toughness steel and a preparation method thereof. The super high-strength and high-toughness steel comprises the following components in percentage by mass: 0.18 to 0.35 percent of C, 0.05 to 0.12 percent of Si, 0.30 to 0.50 percent of Mn, less than or equal to 0.008 percent of P, less than or equal to 0.008 percent of S, 0.8 to 1.5 percent of Cr, 0.10 to 0.30 percent of Mo, 2.5 to 3.5 percent of Ni, 0.05 to 0.12 percent of V, 0.01 to 0.05 percent of RE and the balance of Fe. When the content of C is not higher than 0.25%, the alloy contains 0.0005-0.003% of B and the balance of Fe and other inevitable impurities; the preparation process comprises the steps of smelting, homogenization treatment and blank opening, intermediate annealing treatment, large-deformation warm rolling, subzero treatment and low-temperature tempering treatment. The medium-carbon martensite super-high-strength and high-toughness steel with a large enough metastable austenite phase region is obtained through component design, conventional equipment and a production process are utilized for tissue regulation and control, the size of a martensite block is refined to about 1 micron, and the comprehensive mechanical property of the medium-carbon martensite steel is remarkably improved. The material prepared by the invention has ultrahigh strength and high toughness, and is easy for industrial large-scale production and lower in cost.

The invention relates to a hot-rolled wire rod for a 2260MPa-grade stranded wire and a manufacturing method of the hot-rolled wire rod, after the high-carbon component design of C-Si-Mn-Cr-Mo-Nb-Al is adopted for rolling and spinning to form the wire rod, online molten salt isothermal toughening treatment is carried out, so that the wire rod is firstly subjected to front-section molten salt treatment and is rapidly cooled, and enters a sorbite phase region from an austenite state to form a structure taking a sorbite structure as a main structure; and then carrying out rear-section molten salt treatment, reducing the circulation volume of molten salt, promoting the unconverted retained austenite to be continuously converted into sorbite, carrying out isothermal tempering, promoting fusing of a part of sorbite lamellar layers, and finally carrying out slow cooling through a roller way, so as to prepare the hot-rolled wire rod of which the microscopic structure comprises a mixed structure consisting of tempered sorbite, ferrite and fused sorbite, the tensile strength can reach 1534-1584 MPa, the percentage reduction of area can reach 33%-38%, and the alloy can be used in the application fields of manufacturing 2260 MPa grade stranded wires and the like without additional heat treatment procedures.

The invention provides a multi-step aging treatment method for improving the toughness of an ultrahigh-strength steel ingot, and belongs to the technical field of steel heat treatment. The treatment method comprises the following steps: carrying out solution treatment on the ultrahigh-strength steel at the temperature above AC3, carrying out water cooling or oil cooling to the room temperature, then carrying out subzero treatment, taking out and recovering to the room temperature; the multi-step aging treatment comprises the first step of single-time or multi-time low-temperature aging at the temperature of 400-550 DEG C and the second step of high-temperature aging at the temperature of 550-650 DEG C, and the ultrahigh-strength steel ingot is obtained. According to the method, the content of reversed austenite is increased, especially film-shaped austenite with stable mechanics is increased, meanwhile, it is guaranteed that a precipitated phase is not obviously coarsened, and good obdurability matching is achieved.

Alloy elements are reasonably matched, N and nitrides are added to form elements such as tungsten W, vanadium V, niobium Nb, cobalt Co, rare earth RE and the like for microalloying smelting, a forged and rolled material finished product is subjected to proper heat treatment, and the stainless steel subjected to heat treatment has good heat treatment performance through metallographic observation. According to the stainless steel, nanoscale carbides are separated out in a solid solution state, and fine particles mainly containing nitrides are dispersed and separated out in crystals in a thermodynamic state, so that the material is strengthened and does not diffuse to a crystal boundary, and the room-temperature mechanical property and the high-temperature mechanical property of the material are greatly improved; and when the stainless steel material produced by the method is used for manufacturing related products, the thickness of the stainless steel material can be reduced, and the overall input of the stainless steel material is greatly reduced, so that the large-scale application of noble metal strategic resource nickel is saved, and the aims of saving resources, energy and investment are fulfilled.

The invention belongs to the technical field of nondestructive testing, and particularly relates to a full-matrix microscopic ultrasonic leakage defect three-dimensional reconstruction method. According to the leakage defect three-dimensional reconstruction method, precise positioning and three-dimensional shape reconstruction of tiny complex defects in the austenite thin-wall stainless steel material are achieved, and technical support is provided for leakage micropore detection and three-dimensional representation of the austenite thin-wall stainless steel material. The leakage micropore three-dimensional reconstruction method comprises the following steps: recording an A-Scan original signal and position information of each path point to obtain full-matrix microscopic ultrasonic data; taking the minimum envelope entropy as an optimization target, performing variational mode decomposition and reconstruction on the A-Scan original signal of each path point, and calculating to obtain an optimal solution of a variational model; performing two-dimensional mask extraction on the processed full-matrix microscopic ultrasonic data to generate C scanning images with different depths; extracting to obtain two-dimensional defect edge masks under different depths; and carrying out splicing and volume rendering on a two-dimensional defect edge masking result.

The invention relates to a hot-rolled wire rod for a 2100MPa-grade stranded wire and a manufacturing method thereof, after a high-carbon and high-silicon component system is rolled and spun into a wire rod, the wire rod is cooled at a cooling speed of more than or equal to 31 DEG C / s through online molten salt sorbite regulation and control treatment, and enters a sorbite phase region from an austenite state; the method comprises the following steps of: forming a structure mainly comprising a sorbite structure, performing isothermal tempering, promoting fusing of a part of sorbite lamellas, and finally performing roller way cover opening and slow cooling to prepare the hot-rolled wire rod of which the microscopic structure comprises a mixed structure consisting of tempered sorbite, tempered ferrite and fused sorbite, so that alloy components can be simplified, and the strong plasticity matching and the structure uniformity of the wire rod can be improved; the tensile strength is 1420-1470 MPa, the percentage reduction of area is 36%-41%, the composite material is used for the application field of manufacturing 2100 MPa grade stranded wires and the like, off-line heat treatment can be avoided, and the risk of wire breakage during downstream drawing and twisting is reduced.

The invention relates to a hot-rolled wire rod for a 2200MPa-grade stranded wire and a manufacturing method of the hot-rolled wire rod, after Nb-Al high-carbon component is rolled and spun into a wire rod, the wire rod is subjected to online molten salt strong isothermal treatment, so that the wire rod is firstly subjected to front-section molten salt treatment and enters a sorbite phase region from an austenite state to form a structure taking a sorbite structure as a main structure, and then is subjected to rear-section molten salt treatment to form the hot-rolled wire rod for the 2200MPa-grade stranded wire. The molten salt temperature is increased, the molten salt circulation amount is reduced, unconverted retained austenite is promoted to be continuously converted into sorbite, isothermal tempering is carried out, part of sorbite lamellas are promoted to be fused, and finally slow cooling is carried out through a roller way, so that the hot-rolled wire rod with the microscopic structure comprising a mixed structure composed of tempered sorbite, ferrite and fused sorbite is prepared. According to the method, abnormal structures can be inhibited, the strength of a hot-rolled wire rod can be improved, plasticity and production efficiency are both considered, the tensile strength is 1490-1540 MPa, the percentage reduction of area is 34%-39%, downstream users can avoid off-line heat treatment, and stable production of stranded wires is promoted.

An austenitic stainless steel material is provided that has high creep strength even when used at an average operation temperature of more than 600 to 750° C. after welding with higher heat input, and furthermore, has excellent stress relaxation cracking resistance even after use for a long time period at the average operation temperature after welding with higher heat input. The steel material has a chemical composition which consists of, in mass %, C: 0.030% or less, Si: 1.50% or less, Mn: 2.00% or less, P: 0.045% or less, S: 0.0300% or less, Cr: 15.00 to 25.00%, Ni: 8.00 to 20.00%, N: 0.050 to 0.250%, Nb: 0.10 to 1.00%, Mo: 0.05 to 5.00%, and B: 0.0005 to 0.0100%, with the balance being Fe and impurities, and a ratio of the dissolved N amount (mass %) with respect to the content of N (mass %) in the steel material is 0.40 to 0.90.

The invention relates to a hot-rolled wire rod for a 1960MPa-grade stranded wire and a manufacturing method of the hot-rolled wire rod, after high-carbon components of C-Si-Mn-Cr-B are rolled and spun into a wire rod, the wire rod is subjected to rapid online molten salt isothermal treatment, and the wire rod is subjected to front-section molten salt treatment, so that the wire rod is cooled at the cooling speed of more than or equal to 32 DEG C / s and enters a sorbite phase region from an austenite state; the steel wire rod is subjected to rear-section molten salt treatment, the molten salt temperature is reduced, unconverted retained austenite is promoted to be converted into the sorbite structure, meanwhile, isothermal tempering of the structure and fusing of a part of sorbite lamellas are promoted, and finally slow cooling is conducted through a roller way; the microstructure of the hot-rolled wire rod comprises a mixed structure composed of tempered sorbite, ferrite and fused sorbite, the tensile strength is 1305-1355 MPa, the percentage reduction of area is 37%-42%, and the hot-rolled wire rod is used for being used as base metal to manufacture high-strength stranded wires and other application fields and is beneficial to reducing the risk of wire breakage.

The invention relates to the field of additive manufacturing, and discloses a dynamic phase change control additive ultrahigh-strength steel strengthening and toughening process which comprises the following steps: S1, constructing a phase change structure design target which comprises retained austenite distribution, a structure space structure and mechanical property requirements; s2, based on the phase change structure design target, establishing a free energy model taking a phase field variable as a core for representing a phase change driving behavior between austenite and martensite; s3, on the basis of the free energy model, constructing a multi-field partial differential control model coupling phase field evolution, element diffusion and heat conduction; and S4, in combination with the multi-field partial differential control model, determining an interface adsorption parameter, a diffusion coefficient and a thermophysical parameter based on experimental characterization data. According to the method, path parameters are optimized through a multi-field partial differential control model and tissue deviation feedback, and accurate control of the phase change tissue and dynamic closed-loop adjustment of the machining process are achieved.

The invention belongs to the field of metal materials, and provides a hard alloy wear-resistant steel ball suitable for mine ore grinding and a preparation method thereof.The hard alloy wear-resistant steel ball is prepared from waste steel pig iron as a basic raw material and chemical components including 2.1%-2.2% of C, 9.8%-10.0% of Cr, 0.10%-0.20% of V and 0.03%-0.06% of Ti; a core-shell precipitated phase microstructure design with MN / MCN as a hard core and chromium carbonitride as a gradient self-passivation shell layer is formed through medium-frequency induction furnace smelting, controlled nitrogen introduction establishment of a V-Ti-C-N microalloy system, bottom pouring solidification and austenitizing quenching and tempering heat treatment processes, and the performance indexes that the surface hardness is HRC60-63 and the core hardness is HRC54-58 are achieved; the average particle size of a core-shell precipitated phase is in dispersed distribution of 20-200nm, the shell thickness is 5-50nm, and the alloy steel ball has excellent wear resistance and corrosion resistance under the high-impact and high-wear working conditions of wet ore grinding, solves the problem of insufficient wear resistance and corrosion resistance of a traditional alloy steel ball, and has wide mine ore grinding application value.

The invention relates to the technical field of HB450-grade thick-specification wear-resistant steel plates, in particular to a flame cutting delayed crack-free HB450-grade thick-specification wear-resistant steel plate and a production method thereof. The steel is composed of the following chemical components in percentage by weight: 0.18%-0.22% of C, 1.00%-1.10% of Si, 0.8%-1.0% of Mn, 0.015%-0.03% of Nb, 0.6%-0.70% of Cr, 0.06%-0.09% of Al, 0.0005%-0.0020% of B, more than or equal to 1.4% and less than or equal to 1.6% of Mn and Cr, and the balance of Fe and inevitable impurities. The production process flow comprises the steps of smelting, refining, slab continuous casting, casting blank heating and slow cooling, slab heating, controlled rolling, stacking and slow cooling, quenching and tempering heat treatment, flame cutting with temperature and slow cooling with hot water. The surface hardness is larger than or equal to HB450, the thickness ranges from 40 mm to 80 mm, the tensile strength is larger than or equal to 1250 MPa, the retained austenite content is 5%-7%, delayed cracks do not exist after fire cutting, the trimming hardness is larger than or equal to HB410, AKV at the temperature of-40 DEG C is larger than or equal to 40 J, and A is larger than or equal to 12%.

The invention relates to a high-strength outer plate with excellent flanging forming performance and a preparation method, and belongs to the technical field of steel manufacturing. The high-strength outer plate comprises the following chemical components in percentage by mass: 0.05%-0.14% of C, 0.1%-0.4% of Si, 0.8%-1.4% of Mn, less than or equal to 0.01% of P, less than or equal to 0.005% of S, 0.5%-1.0% of Al, 0.01%-0.04% of Ti and a matrix element Fe, the microstructure of the high-strength outer plate comprises, by area ratio, 80%-90% of ferrite, 5%-15% of martensite and 2%-5% of retained austenite. By designing chemical components and microstructures, ferrite provides good elongation and deformability, martensite improves the strength of the material, and the element Ti realizes grain refinement by forming a precipitated phase, so that not only is the requirement on the waviness of the outer plate favorably realized, but also the hole expansion rate of the material can be improved. According to the obtained high-strength outer plate, the balance of various mechanical properties such as strength, ductility and hole expansion rate is achieved while the surface quality is met, and the forming and performance requirements of the outer plate are met.

The present invention relates to a heat treatment method for a high-strength, tough, lightweight, wear-resistant high-manganese steel casting, and the steps are as follows: pretreatment: coating an anti-oxidation protective coating on the surface of the high-manganese steel casting; water toughening treatment: heating the high-manganese steel casting to the water toughening temperature at a preset speed, keeping the temperature and then water quenching; cryogenic treatment: cooling the high-manganese steel casting after water toughening to the cryogenic treatment temperature and keeping the temperature; aging treatment: heating the high-manganese steel casting after cryogenic treatment to the aging temperature and keeping the temperature, keeping the temperature, and then air cooling to room temperature, and the interval between cryogenic treatment and aging treatment is not more than 1h; shot peening treatment: shot peening treatment is performed on the surface of the high-manganese steel casting after aging treatment. The present invention utilizes a combination of water toughening, cryogenic treatment and aging treatment to obtain a single austenite structure, obtain an effective dispersed nano-scale carbide structure, and effectively improve the grain refinement and solid solution strengthening effect of the high-strength, tough, lightweight high-manganese steel.

The invention provides a continuous production method of a high-strength and high-toughness austenitic stainless steel plate with a 3D full-gradient structure, and belongs to the technical field of stainless steel plate production. According to the method, an austenitic stainless steel plate is subjected to cold rolling and cutting, the size specification and the surface quality of the austenitic stainless steel plate are controlled, and then the rolled austenitic stainless steel plate is subjected to austenitizing treatment; or the austenitic stainless steel plate is firstly subjected to hot rolling to control the size specification, then rapid cooling is conducted, and the coarse-grain single-phase austenite structure is obtained. And then, reciprocating torsional deformation is conducted on the coarse-grain single-phase austenitic stainless steel plate, on the basis that the macroscopic size specification of the coarse-grain single-phase austenitic stainless steel plate is not changed, combination of the strength and the toughness of the coarse-grain single-phase austenitic stainless steel plate is greatly improved, and finally the plate is rolled into a The size specification and the surface quality of the plate are accurately controlled by adjusting a rolling process; and meanwhile, controllable construction of a 3D full-gradient structure is achieved by regulating and controlling reciprocating torsion technological parameters, and therefore cooperation of high strength and high toughness is achieved.

A ferrite-austenite duplex stainless steel material having a composition containing, by mass, 0.001 to 0.050% of C, 0.01 to 0.50% of Si, 1.0 to 4.5% of Mn, 0.050% or less of P, 0.030% or less of S, 1.5 to 3.5% of Ni, 19.6 to 24.0% of Cr, 0.01 to 1.00% of Mo, 0.01 to 1.20% of Cu, 0.010 to 0.090% of N, less than 0.130% of C + N, and the balance of Fe and impurities. The ferrite-austenite duplex stainless steel material has a metal structure in which the value of Md represented by formula (1) is 50.0-150.0 DEG C and the austenite phase is 25-49 vol%. In addition, the value of Md, which is represented by formula (1), of the austenite phase is 35.0-100.0 DEG C. Md = 551-462 (C + N)-9.2 Si-8.1 Mn-29 (Ni + Cu)-13.7 Cr-18.5 Mo (1) In the formula, the element symbols represent the content (mass%) of each element.

The invention discloses a hydrogen embrittlement-resistant heterostructure medium manganese steel and a preparation method thereof, and the medium manganese steel comprises the following components in percentage by mass: 0.05-0.3% of C; 3 to 12% of Mn; 0-8% of Al; 0.05% to 0.3% of Nb; 0.05% to 0.1% of V; 0.02-0.4% of Mo, and the balance Fe and inevitable impurities. According to the method, a gradient structure is introduced by adopting high-differential-ratio rolling and passes through Qamp; p, heat treatment to regulate and control the austenite stability and structure. According to the method, rolling parameters and Qamp are adjusted; and P treatment temperature and time are adopted, so that multi-scale and gradient distribution and film-shaped retained austenite are formed, the toughness and crack propagation resistance of the material are enhanced, and the capture and inhibition effects of hydrogen atoms in the material are effectively improved. The mechanical property and the hydrogen embrittlement resistance of the medium manganese steel are synchronously improved.

The invention discloses a heat treatment method for improving the low-temperature impact performance of 12Cr13 martensitic stainless steel in the technical field of heat treatment. The heat treatment method comprises the following steps that S1, water quenching pretreatment is conducted, specifically, a forge piece is heated to 940-960 DEG C, and heat preservation is conducted for 1-2 h; s2, quenching cooling: after heat preservation of the forge piece is finished, discharging and water-cooling; s3, quenching and heating: heating the forge piece to 830-850 DEG C, and keeping the temperature for 1-2 hours; s4, quenching cooling: discharging and water-cooling the forged piece after heat preservation is finished; s5, high-temperature tempering is conducted, specifically, the forge piece is heated to 600-680 DEG C, and heat preservation is conducted for 3.5-4.5 h; and S6, tempering and cooling, wherein after heat preservation is finished, discharging and air cooling are conducted, and cooling is conducted to the room temperature. According to the method, the material fastener forge piece is subjected to water quenching pretreatment and fine grain treatment, then the fastener forge piece is heated at the temperature lower than the conventional austenitizing temperature for subcritical quenching, a small amount of retained austenite structures are obtained, and the 0 DEG C impact toughness of the 12Cr13 material fastener forge piece is improved.

The invention belongs to the technical field of metal composite materials and hydrogen storage and transportation materials, and particularly relates to a high-strength hydrogen-embrittlement-resistant layered metal composite material for hydrogen storage and a preparation method and application of the high-strength hydrogen-embrittlement-resistant layered metal composite material. According to the preparation method, the nickel-saving austenitic stainless steel (NEASS) and the 30CrMo steel are alternately overlapped in a multi-layer mode, and the processes of vacuum electron beam welding, high-temperature hot rolling, accumulative ply rolling, multi-stage heat treatment and the like are combined, so that the composite board with the layer number reaching hundreds of layers, firm interface bonding, excellent mechanical performance and good hydrogen embrittlement resistance is prepared; the technical problem that strength, toughness and hydrogen brittleness resistance of an existing metal material in a high-pressure hydrogen environment are difficult to consider at the same time is solved. The obtained composite material has high strength, high plasticity and excellent hydrogen embrittlement resistance, and is suitable for structural materials of high-pressure hydrogen storage tanks, hydrogen conveying pipelines and other key hydrogen energy equipment.

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2400 MPa bridge cable and a manufacturing method of the high-strength complex-phase hot-rolled wire rod. After high-carbon chemical components of Mo-Al-V are rolled and spun into a wire rod, the wire rod is subjected to online molten salt tail end quenching toughening treatment, so that the wire rod passes through front-section molten salt and is cooled at the cooling speed of more than or equal to 35 DEG C / s, part of austenite structures are transformed into quenched martensite, and the quenched martensite structure is cooled at the cooling speed of more than or equal to 35 DEG C / s; the method comprises the following steps of: heating to the temperature of a sorbite phase region through rear-section molten salt, controlling unconverted austenite to be converted into sorbite, carrying out isothermal tempering, and finally, slowly cooling through a roller way to prepare a hot-rolled wire rod of which the microscopic structure comprises a complex-phase structure consisting of tempered martensite and tempered sorbite, so that the control of network carbide and other hard and brittle phase structures can be realized, and the service life of the hot-rolled wire rod is prolonged. According to the steel wire rod, the strength and the structure uniformity of the steel wire rod are improved, the material cost and good plasticity are both considered, the tensile strength is 1665-1705MPa, the percentage reduction of area is 26%-31%, the production efficiency is high, and stable production of 2400 MPa bridge cables is facilitated.

The invention relates to the technical field of high-hardness thick-specification high-wear-resistance steel plates, in particular to a high-hardness 30-80mm thick-specification flame-cutting-delayed-crack-free high-wear-resistance steel plate and a production method thereof. New flame cutting delayed crack preventing components and process design are adopted, the chemical components of the steel plate are mainly characterized by medium carbon, high silicon and niobium microalloying, and the wear-resistant steel plate with low impurity content, uniform and fine martensite and a certain amount of retained austenite structures is obtained after refining, continuous casting, controlled rolling and heat treatment. And formation and expansion of delayed cracks during flame cutting can be inhibited. And during flame cutting, thermal stress and structural stress formed in the cutting process of the thick steel plate are reduced through the cutting process of cutting with temperature and slow cooling with hot water after cutting, and the effect of no delayed crack after cutting is achieved. The surface hardness is larger than or equal to HB500, the tensile strength is larger than or equal to 1350 MPa, AKV at-40 DEG C is larger than or equal to 30 J, A is larger than or equal to 10%, retained austenite is 4%-6%, delayed cracks do not exist after flame cutting, and the flame cutting edge hardness is larger than or equal to HB460.

The invention discloses an electric arc additive manufacturing conformal temperature regulation and control device and method, belongs to the technical field of metal additive manufacturing, and aims to solve the problems of poor molten pool stability, low dimensional precision, serious heat accumulation and the like caused by temperature difference in the electric arc additive manufacturing process. The regulation and control device comprises a cooling device, a heating device, a temperature sensor, a temperature regulation and feedback device and a sliding rail which are assembled through the sliding rail and can keep synchronous movement. In the printing process, the heating device preheats the pre-walking track to enable the pre-walking track to reach a proper printing temperature; the cooling device is used for cooling the formed welding bead in real time; the temperature sensor collects the printing temperature in real time and feeds the printing temperature back to the temperature regulation feedback device, and precise temperature regulation and control are achieved. The method is suitable for additive manufacturing of multiple metal materials such as austenitic stainless steel, martensitic stainless steel and aluminum magnesium alloy, the forming efficiency, the size precision and the forming quality are remarkably improved, and the rejection rate is reduced.