2169 results about "Austenite" patented technology

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 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 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 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.

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.

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 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 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.

The invention relates to the technical field of environment monitoring instruments, and discloses a multi-gas detection mine environment monitoring instrument, which comprises a gas extraction type composite gas monitoring instrument, and further comprises a protection box arranged outside the gas extraction type composite gas monitoring instrument, used for protecting the gas extraction type composite gas monitoring instrument and made of austenitic stainless steel, the probe is arranged at the top of the air exhaust type composite gas monitor, the fixed pipe is communicated with the top of the protection box, the top of the probe is located in the fixed pipe, the guide pipe is connected with the top of the fixed pipe through a flange, and the air exhaust pipe is connected with the other end of the guide pipe through a flange. Through double filtration of the dustproof net and the dust-sticking paper, large-particle dust is intercepted by the dustproof net, fine dust is adsorbed by the dust-sticking paper on the inner wall of the circular truncated cone body, and dust accumulated in a pipeline is discharged through a gap between a baffle and a mounting sleeve through regular blowing of an air blowing pump of the dust removal assembly, so that the dust is prevented from adhering to a probe to block an air path; and the monitoring data accuracy is improved.

The invention relates to the technical field of metal processing, and discloses a production method of an ER2209 austenite ferrite duplex stainless steel welding wire, the ER2209 austenite ferrite duplex stainless steel welding wire comprises an adopted vacuum induction melting furnace and a liquid storage tank, the outer side of the vacuum induction melting furnace is provided with a protective shell, one side of the liquid storage tank is fixedly connected with a conveying pump, and the other side of the liquid storage tank is fixedly connected with a vacuum pump. A cooling assembly is arranged in the protective shell. The preparation method comprises the following steps that S1, raw materials are prepared and smelted; s2, cooling the vacuum induction melting furnace; s3, forging is conducted; s4, hot rolling and solution treatment; s5, acid pickling and surface treatment; s6, cold drawing and intermediate annealing; s7, surface copper plating and finish drawing; and S8, winding and packaging. In the acid pickling process of the wire rod, the oxidation degree of the wire rod is detected, meanwhile, the concentration of the acid pickling solution is adjusted according to the actual situation, and the situation that the surface of the wire rod is excessively corroded or is not thoroughly cleaned due to the fact that the concentration of the acid pickling solution is improper is prevented.

The present application relates to the field of additive manufacturing, and discloses a simulation method for determining a laser powder bed fusion printing process for single-crystal austenitic stainless steel. The simulation method comprises the following steps: S1, establishing a three-dimensional polycrystalline powder bed microstructure model; S2, establishing a three-dimensional temperature field prediction model on the basis of a finite element method; S3, establishing a three-dimensional polycrystalline microstructure evolution model by using a phase-field method; and, S4, coupling the models from steps S1, S2 and S3, and simulating a multi-layer, multi-pass laser powder bed fusion process by using different process parameters, so as to determine appropriate single-crystal process parameters. The present invention replaces conventional trial-and-error experimental methods with numerical simulation methods to determine single-crystal process parameters, thereby greatly reducing the time and economic costs of process exploration, and assisting experiments in revealing the microstructure evolution mechanism of single crystal preparation via laser powder bed fusion additive manufacturing.

The invention belongs to the technical field of metal material preparation, and relates to high-strength and high-plasticity cold-rolled medium manganese steel without a local deformation zone and a preparation method thereof.The preparation method comprises the steps that austenite-ferrite double-phase region annealing is conducted, and a medium manganese steel billet with the microstructure mainly composed of a manganese-rich austenite region and a manganese-poor ferrite region is obtained; carrying out cold rolling treatment on the annealed medium manganese steel billet to obtain a cold-rolled medium manganese steel billet body consisting of martensite and deformed ferrite; the cold-rolled medium manganese steel billet is rapidly heated to the austenite transformation temperature or above, and the medium manganese steel billet with the microstructure mainly composed of austenite with uneven manganese distribution is obtained; and the medium manganese steel billet is quenched to the room temperature, and a medium manganese steel finished product with the microstructure mainly composed of a manganese-rich austenite area and a manganese-poor martensite area is obtained. A martensite matrix and a small amount of metastable austenite in the microstructure ensure good plasticity and strength, a large amount of dislocation inhibits generation of a local deformation zone, and the uniform deformation capacity of the medium manganese steel is ensured.

The invention relates to a stainless steel flux-cored wire for welding 5% Ni steel, the stainless steel flux-cored wire is prepared by coating powder with a stainless steel strip, the mass of the powder accounts for 22%-28% of the total mass of the flux-cored wire, and a flux core comprises the following components in percentage by weight: 15.0%-30.0% of chromium metal powder, 9.0%-20.0% of nickel metal powder, 3.0%-10.0% of molybdenum metal powder, 2.0%-8.0% of electrolytic manganese metal, 30.0%-35.0% of rutile, 0.5%-3.0% of quartz, 2.0%-8.0% of albite, 0.5%-3.0% of potassium feldspar, 0.5%-5.0% of cryolite and 0.2%-0.5% of self-made raw materials. And the balance of reduced iron powder and inevitable impurities. The external steel strip is an austenitic stainless steel strip 304L, and the carbon content of the external steel strip is smaller than or equal to 0.025%. The flux-cored wire is mainly matched with a steel plate with the Ni content being about 5% for welding, the low-temperature impact of a welded joint of the flux-cored wire at the temperature of-140 DEG C can reach 40 J, the tensile strength is larger than 600 MPa, and the flux-cored wire is good in crack resistance and excellent in comprehensive performance.

The invention discloses a low-temperature high-toughness austenitic stainless steel welding wire and a preparation method thereof, and relates to the technical field of welding materials, in particular to a welding wire with high-toughness mechanical properties of formed cladding metal in a low-temperature environment and a preparation method of the welding wire. The Ti element is introduced into the welding wire, the dosage relation of the Al element and the Ti element is controlled, and the mass ratio of Al to Ti is kept to be (5-10): 1; a proper amount of Al element can play a role in purifying a molten pool during welding work, a proper amount of Ti element can effectively stabilize an austenite phase, and therefore it is guaranteed that the welding wire has the basic welding capacity, and meanwhile after the welding wire is converted into cladding metal, the welding wire is not prone to deformation. The material characteristics and the like of the material can meet the use requirements at room temperature and ultralow temperature environment, that is, the material has and keeps good tensile property, impact property and the like, so that pipelines, containers and the like prepared from the material can be used for transmitting or loading special low-temperature materials such as liquid hydrogen, liquid helium and the like.

The invention provides high-strength and high-toughness steel based on laser rapid melting, and the alloy components of the high-strength and high-toughness steel comprise the following elements in percentage by mass: 0.1-0.3% of C, 0.1-2.6% of Mn, 0.1-1.5% of Ni, 0.1-4% of Mo, 1-4.5% of W, 0.1-1.2% of Si and the balance of Fe and inevitable impurity elements, in the impurity elements, P is less than or equal to 0.01%, and S is less than or equal to 0.02%; wherein the ratio of the sum of the mass percentages of Ni and Mn to the mass percentage of Si is not less than 1.572. Meanwhile, the invention further discloses an additive manufacturing method of the high-strength and high-toughness steel based on laser rapid melting. According to the high-strength and high-toughness steel, the influence of alloying elements on an Mf point and an Ac1 point is fully considered during design, it is ensured that all sedimentary structures are lath martensite, and the macrosegregation phenomenon in solidification structures is avoided through laser rapid melting; and then nanoscale film austenite is obtained on the two sides of the lath martensite through in-situ laser ultra-fast heat treatment or off-site infrared ultra-fast heat treatment, and the high yield strength of 1200 MPa and the ultrahigh Charpy V-shaped notch impact energy of 120 J are obtained.

The invention relates to the technical field of medium manganese steel, in particular to high-strength and high-toughness medium manganese steel and a preparation method thereof.The preparation method is characterized by comprising the steps that S1, smelting is conducted through an electric furnace according to the chemical component ratio of the medium manganese steel, then refining is conducted through a ladle refining furnace, then vacuum degassing treatment is conducted through a vacuum circulation degassing method, and then continuous casting is conducted to form a plate blank with the thickness being 200-300 mm; s2, the plate blank is heated to 1150-1250 DEG C in a walking beam furnace, heat preservation is conducted for 2-4 hours, and then a controlled rolling technology is adopted to machine the plate blank into a steel plate within the range of 4-20 mm; s3, after rolling is completed, the steel plate is treated through a composite cooling technology of ultra-fast cooling and laminar cooling; s4, the cooled steel plate is heated to 750-850 DEG C, heat preservation is conducted for 10-60 minutes, and a ferrite and austenite double-phase structure is formed; the comprehensive performance is greatly improved, and excellent strength, plasticity, low-temperature toughness and welding adaptability are shown.

The invention discloses an austenitic stainless steel welding wire for a liquid hydrogen storage tank and a preparation method and application of the austenitic stainless steel welding wire, and belongs to the technical field of welding materials and preparation of the welding materials. The welding wire solves the problem that the low-temperature performance of a welding seam is poor when the current welding wire for the liquid hydrogen storage tank is used for welding. The welding wire comprises the following chemical components in percentage by mass: less than or equal to 0.02% of C, 0.4-1.5% of Si, 5.0-7.5% of Mn, less than or equal to 0.020% of S, less than or equal to 0.030% of P, 16.0-22.0% of Cr, 15.0-18.0% of Ni, 2.0-5.0% of Mo, 0.05-0.2% of N, less than or equal to 0.01% of O and the balance of Fe and inevitable impurities. According to the welding wire, deposited metal is low in low-temperature embrittlement tendency, high in low-temperature strength and excellent in low-temperature impact and fracture toughness. The welding wire is used for welding the austenitic stainless steel liquid hydrogen storage tank and is wide in application range, and the mechanical property of deposited metal is good.

The invention discloses a hydrogen embrittlement-resistant welding wire for tailor welding of ultrahigh-strength aluminum-silicon coating hot-formed steel and a welding method, and belongs to the technical field of metal materials. 5.0%-7.0% of Ni; 0.3%-0.6% of Mo; 0.08% to 0.12% of Nb; mo, Nb and C react to form Mo2C / NbC nanophase fixed free hydrogen; 0.05%-0.1% of V: carrying out a reaction to form VC nanophase fixed free hydrogen; 0.5% to 0.8% of La; 0.3%-0.5% of Ce; 0.1%-0.5% of Ti; according to the invention, hydrogen atoms diffused in the welding process can be captured, the hydrogen content in a welding seam is obviously reduced, and the diffusible hydrogen amount is reduced by more than 40% under the hydrogen capturing effect of retained austenite, so that the hydrogen-induced crack sensitivity is reduced by 70%.

The invention relates to the technical field of alloys, and discloses 2400MPa-grade ultrahigh-strength steel and a preparation method thereof. The 2400 MPa grade ultrahigh-strength steel comprises the following chemical components in percentage by mass: 0.3%-0.5% of C, 1.0%-2.5% of Si, 3.5%-5% of Mn, 0.2%-0.3% of V, 1%-3% of Ni, 0.02%-0.05% of Nb, 0.3%-0.5% of Mo, 0.5%-2% of Cr and the balance of Fe and inevitable impurities. The microstructure of the 2400 MPa grade ultra-high strength steel comprises martensite and austenite, the average grain size of the martensite ranges from 0.4 micrometer to 2.0 micrometers, and the ratio of the grain length axis to the grain length axis of the martensite is smaller than or equal to 1.6. The strength, plasticity and toughness of the 2400MPa-grade ultra-high-strength steel are improved, and the 2400MPa-grade ultra-high-strength steel has high strength, high plasticity and high toughness.

The invention discloses a casting shrinkage-proof device for hot-working casting, and belongs to the technical field of hot-working casting, by arranging a heating mechanism and a knocking mechanism, through vibration and disturbance generated by knocking, the static state of 21800 austenitic stainless steel metal liquid in a casting mold can be broken, and the shrinkage-proof performance of the casting is improved. According to the technical scheme, small bubbles originally attached to the interior or the wall face of liquid are disturbed and start to float upwards, meanwhile, vibration can improve the liquidity of the metal liquid, crank knocking is started in the process that the metal liquid is injected into a casting mold, knocking is still continuously kept after the metal liquid is injected, knocking power is from pushing of steam, and therefore the effect of improving the fluidity of the metal liquid is achieved. No other external force is needed in the process, and the knocking frequency is gradually reduced until the knocking frequency is completely stopped along with cooling of metal, weakening of power generated by steam and reduction of the casting mold temperature, so that the purpose of preventing the stability of metal liquid during condensation from being damaged by excessive knocking is achieved.

An austenitic stainless steel material according to the present disclosure contains, in mass %, C: 0.030% or less, Si: 0.01 to 1.00%, Mn: 0.01 to 2.00%, P: 0.040% or less, S: 0.0100% or less, Ni: 8.00 to 18.00%, Cr: 15.00 to 25.00%, Mo: 0.10 to 5.00%, Nb: 0.20 to 1.00%, N: 0.060 to 0.250%, Cu: more than 2.00 to 4.00%, and B: 0.0010 to 0.0100%, and satisfies Formula (1):Nbs×0.8>Nbb(1)where, in Formula (1), an average Nb concentration in percent by mass in an outer layer from a surface of the austenitic stainless steel material to a depth of 10 μm is substituted for Nbs, and an average Nb concentration in percent by mass in a region excluding the outer layer of the austenitic stainless steel material is substituted for Nbb.

The invention discloses austenite hydrogen-resistant stainless steel and a preparation method thereof, and belongs to the field of metal materials. The austenitic hydrogen-resistant stainless steel comprises the following chemical components in percentage by mass: less than or equal to 0.06% of C, less than or equal to 1.00% of Si, 3.00-5.00% of Mn, 19.50-22.00% of Cr, 11.00-13.00% of Ni, 1.50-2.00% of Mo, 1.50-3.50% of Cu, 0.20-0.30% of V, 0.10-0.23% of Nb, 0.30-0.40% of [N], less than or equal to 0.01% of P, less than or equal to 0.004% of S, less than or equal to 0.003% of [O] and the balance of Fe. The preparation method comprises the steps of vacuum induction melting, high-temperature homogenization, forging, hot rolling and heat treatment. The method solves the problems that traditional austenitic stainless steel is poor in hydrogen embrittlement resistance and an existing process is difficult to consider precise regulation and control of high purity, low impurities and hydrogen trap elements at the same time.

According to the low-strength high-formability austenitic stainless steel and the manufacturing method thereof, C + N is controlled to be smaller than or equal to 0.035%, the manganese content is controlled to be within 1.5%, the tin content is limited to be 0.01%-0.30%, the copper content is limited to be 2.4%-4.5%, and the tin-copper ratio is that (Sn / Cu) * 1000 is larger than or equal to 5 and smaller than or equal to 50, so that it is guaranteed that tin exerts the beneficial effects such as the corrosion resistance is improved, and the harm of tin segregation can be controlled to be at the low level; according to the finally obtained austenitic stainless steel, the yield strength is smaller than or equal to 160 Mpa, the tensile strength is smaller than or equal to 500 Mpa, the ductility is larger than or equal to 55%, the grain size grade is 6-8, edge cracks cannot occur during hot rolling, the martensite content of a cup drawing deformation part is 0.05% or below during large deformation machining, in other words, the austenite phase is still stable under the complex deformation condition, deformation cracks are avoided, and the service life of the austenitic stainless steel is prolonged. The comprehensive effects of high corrosion resistance, low strength and high forming machinability of the material are achieved.