302 results about "Hot work" patented technology

The invention relates to the technical field of process optimization, and discloses a hot work die steel heat treatment process optimization method and system.The method comprises the steps that hot work die steel samples are collected under multiple sets of different process conditions, and a performance basic data set is obtained; constructing a multi-target coordination optimization model based on the performance basic data set; performing phase change detection on the hot work die steel sample to obtain phase change monitoring data; performing prediction in combination with the phase change monitoring data to obtain a performance prediction result; and solving an optimal process parameter combination based on the performance prediction result and the multi-target coordinated optimization model, and realizing simultaneous optimization and coordinated balance of a plurality of performance indexes in the heat treatment process of the hot work die steel by making full use of associated information among different performance indexes.

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 utility model relates to the technical field of early warning devices, and discloses a fire operation leaving early warning device which comprises a base, a supporting frame is vertically and fixedly connected to the top of the base, a lifting plate is vertically and slidably connected to the surface of the supporting frame, a connecting box and a control box are fixedly connected to the surface of the lifting plate, and the control box is arranged at the top of the connecting box. A sliding mechanism for sliding the lifting plate is arranged on the surface of the base, a mounting plate is horizontally and fixedly connected into the supporting frame and arranged at the top of the supporting frame, a human body induction module is mounted on the surface of the mounting plate, and universal wheels are mounted at the four corners of the bottom of the base. According to the device, the lifting plate is arranged in an up-down sliding manner, so that the device can be conveniently used for people with different heights and different use scenes during use, the use effect of the device is improved, meanwhile, the device is matched with real-time monitoring of the human body sensing module, prompting is conveniently carried out when the device leaves people, and the safety of the device 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 discloses a jig frame structure and method for movable deck welding deformation control. The jig frame structure is characterized in that a transverse supporting truss comprises a plurality of transverse T-shaped beams distributed at intervals; the longitudinal supporting truss comprises a plurality of longitudinal T-shaped beams which are distributed at intervals, each longitudinal T-shaped beam is perpendicular to the transverse T-shaped beams, and each longitudinal T-shaped beam is fixedly connected with the transverse T-shaped beams; two adjacent longitudinal T-beams and two adjacent longitudinal T-beams define a rectangular unit, a reinforcing plate is arranged in each rectangular unit, the reinforcing plates are parallel to the longitudinal T-beams or the transverse T-beams, and when the reinforcing plates are parallel to the longitudinal T-beams, the reinforcing plates are fixedly connected with the transverse T-beams; when the reinforcing plates are parallel to the transverse T-beams, the reinforcing plates are fixedly connected with the longitudinal T-beams. According to the jig frame structure, the internal stress of the movable deck can be effectively reduced, the camber of the transverse T-shaped beam and the longitudinal T-shaped beam is pre-increased in advance, a large amount of hot work correction work after completion is reduced, and the jig frame structure belongs to the technical field of ship accessory outfitting equipment manufacturing.

The utility model relates to vertical annealing equipment for a metal ultra-thin strip and an operation method, and belongs to the related technical field of metal ultra-thin strip hot working, the vertical annealing equipment comprises a furnace body device, a tension measuring device, a direction roller, an unwinding device, a winding device, a straightening device and a deviation rectifying device, the furnace body device comprises a muffle tank and a furnace body shell, a plurality of groups of elastic brackets fixedly connected with the furnace body shell are arranged on the outer side of the muffle tank in the length direction of the muffle tank, and the top of the muffle tank is fixedly connected with the top of the inner side of the furnace body shell through the top elastic bracket, so that the service life of the muffle furnace is prolonged; one side of the furnace body shell is respectively connected with a molecular pump and a gas inlet through steel pipes, the other side of the furnace body shell is provided with a gas outlet, and pipelines for connecting the molecular pump, the gas inlet and the gas outlet are respectively provided with a gas valve, so that the conversion between vacuum annealing and atmosphere annealing in the muffle furnace is realized; and the straightening device comprises a plurality of straightening rollers, so that high-precision straightening can be carried out on the annealed metal ultra-thin strip, and the strip shape quality of the strip is effectively improved.

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 discloses a manufacturing method of high-quality electric furnace hot work die steel. The manufacturing method comprises the following steps: primarily smelting a die steel raw material by adopting an EAF furnace; the metal raw materials obtained through primary smelting are refined through an LF furnace; entering a VD furnace for vacuum degassing, and improving carbides by adopting a magnesium core-spun yarn; casting a 13t or 20t steel ingot by using the obtained molten steel, using casting powder and hanging, using a heat generating agent after casting, demolding after mold cooling, and thermally sending the demolded steel ingot to a forging area for heating or thermally charging and annealing; and forging by adopting a temperature programming mode, and finally carrying out heat treatment. The forging rod has the advantages that a die manufactured after the forging rod is processed and subjected to heat treatment is used for producing 6 series of aluminum alloy sections and the like by an extruder of 5000 tons or above, die cracking and early failure are avoided, the service life of the die is equivalent to that of electroslag 4Cr5MoSiV1 (H13), the manufacturing cost is greatly reduced, and the effect is good.

The invention discloses hot work die steel with high toughness and high thermal stability as well as a preparation method and application thereof, and belongs to the technical field of die steel, the hot work die steel comprises the following chemical components in percentage by mass: 0.22%-0.32% of C, 0.10%-0.30% of Si, 0.30%-0.50% of Mn, less than or equal to 0.015% of P, less than or equal to 0.003% of S, 2.80%-3.50% of Mo, 4.70%-5.20% of Cr, 0.30%-0.60% of V, 0.03%-0.05% of N and the balance of Fe and inevitable impurity elements. By means of the method, high-density forming of large-size die steel can be achieved, 3D printing additive manufacturing forming can be achieved, the die steel material which is small in grain size, excellent in toughness and high in heat stability is obtained, and premature initiation and expansion of cracks are avoided. The problem that common hot work die steel is prone to cracking due to thermal fatigue cracks in the service process is solved.

The invention relates to the technical field of metal heat treatment, in particular to a production process of high-strength and high-toughness hot work die steel. According to the hot work die steel prepared through the method, the problems that die steel is insufficient in toughness and low in hardness are solved. Through the process steps of smelting and casting, hot forging, annealing, circulating hot forging and annealing, solid solution-quenching-partitioning treatment, tempering treatment, finishing and surface treatment, process parameters of all treatment stages are adjusted, and the steps of nitriding treatment and carburizing treatment are added in the surface treatment stage. The high-strength and high-toughness hot work die steel is high in toughness, high in hardness and good in thermal fatigue resistance.

The invention belongs to the technical field of stainless steel hot working, and discloses a martensitic stainless steel hot rolled steel coil manufacturing method capable of solving the edge crack problem in the wide rolling process so as to improve the yield. Comprising the steps that firstly, a continuous casting slab is heated for the first time in a heating furnace, the temperature of a heating section is 1100-1150 DEG C, the temperature of a soaking section is 1150-1200 DEG C, the heat preservation time of the soaking section is (1.00-1.25) t min, and t is the actually measured thickness mm of the slab before the slab enters the furnace; secondly, the heated continuous casting sheet billet is rolled into an intermediate billet through a roughing rolling unit, and the outlet temperature of the roughing rolling unit is 1000-1010 DEG C; 3, returning the intermediate billet to the heating furnace for secondary heating, wherein the heat preservation time of a soaking section of the secondary heating is shorter than that of the primary heating; fourthly, the intermediate billet heated for the second time is fed into a roughing rolling unit to be rolled, and the outlet temperature of the roughing rolling unit is 1000-1010 DEG C; 5, putting into a hot coil box after rolling; sixthly, the steel plate is fed into a finishing mill group to be rolled to the target thickness, and the finish rolling temperature is 1000-1050 DEG C; and 7, after finish rolling, laminar cooling is conducted to 300-400 DEG C, and then coiling is conducted.

The invention discloses a fire operation management system based on artificial intelligence and a use method thereof, and relates to the field of safety management of building engineering construction. The front end of the system is composed of an AI fire monitoring robot and a WeChat management applet, and the rear end of the system comprises an enterprise end management large screen and a project management platform. After information is input by creating a database, an operator initiates a fire application through an applet, and a license and a disclosure book are generated according to process approval. The AI fire monitoring robot carries out human face recognition before operation, carries out real-time monitoring and early warning by using technologies such as images, organisms and sensors in the process, and carries out continuous monitoring after operation until hidden dangers are eliminated and generates a report. The system effectively solves the problems of tedious flow, difficulty in tracing, lacking in supervision and the like in the traditional fire operation management, achieves the precise management and control of the whole process of the fire operation, remarkably improves the operation safety and management efficiency, and provides an intelligent and efficient safety management guarantee for the fire operation in the fields of building construction and the like.

The invention belongs to the technical field of ferrous metallurgy and material modification, and particularly relates to a preparation method of green short-process hot work die steel, which comprises the following steps: obtaining scrap steel, adding alloy, and smelting to obtain molten steel; the molten steel is refined through fluoride-free rare earth refining slag, and refined molten steel is obtained; adding a nanoparticle modifier into the refined molten steel to obtain modified molten steel; and the modified molten steel is subjected to continuous casting or die casting, and the hot work die steel is obtained. According to the method, the fluorine-free rare earth slag refining and nano particle modification combined technology is adopted, fluorine-containing refining slag and traditional electroslag remelting are effectively replaced, power consumption and carbon emission in the smelting process are reduced, the technical development requirements of current green manufacturing and dual-carbon targets are met, and green short-process manufacturing of the hot work die steel is achieved; and the prepared hot work die steel has higher cleanliness, a more uniform organization structure and more excellent thermal fatigue performance.

To provide a ferritic stainless steel and a steel sheet thereof, having excellent oxidation resistance and hot workability.SOLUTION: A ferritic stainless steel contains 0<C≤0.03 mass%, Si≤0.05 mass%, 0.30≤Mn≤1.00 mass%, P≤0.05 mass%, S≤0.05 mass%, Cu≤0.10 mass%, Ni≤0.20 mass%, 20.0≤Cr≤25.0 mass%, Co≤0.10 mass%, Al≤0.10 mass%, 0.01≤Ti≤0.30 mass%, 0<N≤0.03 mass%, and 0.05≤La≤0.30 mass%. The balance is Fe and unavoidable impurities. The ferritic stainless steel further contains at least one selected from the group consisting of 0.05≤V≤2.00 mass%, 0.05≤Nb≤2.00 mass%, 0.05≤Ta≤0.30 mass%, and 0.0010≤B≤0.0100 mass%. A steel sheet is made of the ferritic stainless steel.SELECTED DRAWING: Figure 1

To provide a ferritic stainless steel and a steel sheet thereof, having excellent oxidation resistance and hot workability.SOLUTION: A ferritic stainless steel contains C≤0.03 mass%, Si≤0.05 mass%, 0.30≤Mn≤1.00 mass%, P≤0.05 mass%, S≤0.05 mass%, Cu≤0.10 mass%, 20.0≤Cr≤25.0 mass%, V≤0.10 mass%, Co≤0.10 mass%, Al≤0.10 mass%, 0.01≤Ti≤0.30 mass%, N≤0.03 mass%, and 0.05≤La≤0.30 mass%. The balance is Fe and unavoidable impurities. The ferritic stainless steel further contains 0.10≤W≤2.00 mass% and / or 0.10≤Mo≤2.00 mass%. The ferritic stainless steel may further contain 0≤Ni≤2.00 mass%. A steel sheet is made of the ferritic stainless steel.SELECTED DRAWING: None

The invention provides a fire operation safety management system, which belongs to the technical field of operation safety supervision and comprises an operation application unit, a measure confirmation unit, an operation examination and approval unit, a start confirmation unit, an operation implementation unit and an operation completion unit. The measure confirmation unit matches and confirms operation safety measures; the job approval unit matches an approval process including multi-stage approval and face recognition verification; the work starting confirmation unit verifies the tools, senses the environment and secondarily confirms gas monitoring; the operation implementation unit is linked with data to supervise the operation state; and the work completion unit guides acceptance, returns tools and the like and archives work tickets. The system has the beneficial effects that operation approval management is strengthened, an intelligent safety protection system of'full-chain control, whole-process trace reserving and full-risk pre-judgment 'is constructed by means of hardware auxiliary means such as field monitoring and personnel positioning, closed-loop management of an operation process is realized, and intrinsic safety transformation from an enterprise to active prevention is promoted.

The invention discloses a method for identifying and judging violation of fire operation based on machine vision, which belongs to the technical field of fire operation identification, and specifically comprises the following steps: acquiring infrared thermal imaging data and optical image data of a fire operation area, and obtaining surface temperature distribution and outline of a fire tool; for the infrared thermal imaging data, extracting temperature gradient change characteristics of a heating area of the fire tool, and generating a dynamic deformation track model according to the temperature gradient change characteristics; for the optical image data, through contour difference analysis between continuous frames, extracting the contour offset of the hot tool after thermal deformation, and establishing a corresponding relation on a time sequence with the dynamic deformation track model; when the corresponding relation between the outline offset of the fire operation tool and the temperature gradient change characteristics of the fire operation tool deviates from a preset correlation threshold range, judging that the operation is illegal operation; according to the invention, the capability of judging complex violation behaviors is enhanced.

The application relates to the technical field of die steel, and particularly discloses a high-performance strong and tough hot work die steel and a preparation method thereof. The high-performance strong and tough hot work die steel comprises the following raw materials: C 0.3-0.5%, Si 0.3-0.8%, Co 0.2-0.3%, Mg 0.1-0.14%, Ti 0.23-0.35%, V 0.38-0.56%, Al 0.08-0.14%, Mn 0.1-0.18%, NiCrMo alloy powder 7-10%, P<=0.05%, S<=0.02%, and the balance of Fe and inevitable impurities. The raw materials are sequentially put into a vacuum induction furnace for smelting and poured into a steel ingot; the steel ingot is annealed and hot-rolled and then air-cooled to room temperature, and then heat treatment is carried out; the preparation method is simple and the preparation conditions are mild; the obtained hot work die steel is excellent in hot strength, toughness and wear resistance, and can meet the market application requirements.

The embodiments of the present application relate to the technical field of hot work special operations, and disclose a real-time alarm method, alarm device, and computer-readable storage medium for hot work special operations. The method includes: acquiring an operation image of a target hot work special operation site in real time, and determining the hot work fire source in the operation image; determining a target detection area in the operation image with the hot work fire source as the center; determining the fire occurrence value of the target hot work special operation site based on the target detection area; if the fire occurrence value is greater than a preset safety threshold, issuing an alarm prompt for the target hot work special operation site. The real-time alarm method for hot work special operations provided by the embodiments of the present application can monitor the safety of the hot work special operation site in real time, comprehensively, and automatically, and greatly improve the safety of hot work special operations.

The invention belongs to the technical field of die steel, and relates to AOD nitrogen-reduced hot work die steel H13 and a smelting method thereof. The main chemical components of the hot work die steel meet the requirements of German standard 1.2344 steel, and the N content is not higher than 0.015. Compared with the hot work die steel (H13) produced by the original smelting method, the finally obtained product has lower nitrogen element content and better impact toughness through innovative adjustment of the smelting process and flow, so that the hot work die steel has a wider high-end market application prospect, and the selection range of the die steel of the steel type in the market is expanded. Meanwhile, the metallurgical process method provided by the invention is simple and convenient to operate and suitable for industrial large-scale production.

The utility model discloses an aluminum bus welding rapid preheating device which comprises a baking gun gas conveying pipe, the tail end of the baking gun gas conveying pipe is connected with a gas inlet pipe joint, the gas inlet pipe joint comprises a combustible gas pipe joint and a combustion-supporting gas pipe joint, and the combustible gas pipe joint and the combustion-supporting gas pipe joint are connected to form a Y-shaped gas inlet pipe joint. A holding soft sleeve is connected to the outer surface of the baking gun gas conveying pipe in a sleeving mode, an L-shaped pipe connector is connected to the front end of the baking gun gas conveying pipe, a semi-annular bent pipe frame is installed at the top end of the L-shaped pipe connector, and a plurality of welding gun nozzles are installed on the inner side of the semi-annular bent pipe frame. According to the scheme, the front end opening of the gas conveying pipe of the baking gun is connected with the semi-annular bent pipe frame through the L-shaped pipe connector, and the welding gun nozzles which are symmetrically distributed are arranged on the inner side of the semi-annular bent pipe frame. The aluminum bus located at the circle center of the semi-annular bent pipe frame can be welded and preheated at the same time from multiple angles, the welding preheating efficiency is higher, and operation is easy.

The application discloses a manufacturing method of a welded multilayer gas distribution plate of a CVD (Chemical Vapor Deposition) device, and the method comprises the following steps: single-piece machining; single-piece inspection; ultrasonic cleaning; vacuum drying; welding I; post-welding machining; welding II; heat treatment; shielding; grinding; unshielding; shape correction; turning; surface polishing; ultrasonic degreasing cleaning; surface blow-drying; and vacuum drying. The method can satisfy the requirements that the flatness of the welded multilayer gas distribution plate is less than or equal to 0.02 mm, the parallelism is less than or equal to 0.02 mm, and the position degree is less than or equal to 0.1 mm. The welding and the heat treatment belong to hot processing, the parts will be deformed, the deformation amount is large, the requirements that the flatness is less than or equal to 0.02 mm, the parallelism is less than or equal to 0.02 mm, and the position degree is less than or equal to 0.1 mm cannot be satisfied, and the material is soft after the heat treatment, the aluminum chips generated by the turning and milling processing will block the holes of the gas distribution plate, so that the gas distribution plate loses the function. The process is suitable for the welding type double-layer, multilayer, first-order hole, second-order hole, third-order hole and multi-order hole gas distribution plate.

The invention relates to the technical field of hot working equipment, and provides a local temperature-controllable brazing furnace system and a method for welding a water cooling plate and a side cooling plate thereof.A furnace body with the front portion, the rear portion and the top portion capable of being opened and closed is arranged for welding, in this way, closed welding is conducted, the external environment is blocked, and the furnace body is heated through twelve linear silicon carbide rods; nitrogen is introduced outside the furnace body by arranging a copper pipe, the nitrogen is preheated by the copper pipe and enters the furnace, the temperature is uniform, and it is guaranteed that the oxygen content of the furnace body is smaller than or equal to 18 ppm; when the brazing furnace is used for welding a water cooling plate and a cold measuring plate, a welding tool is installed on the support in the furnace body, then a welding piece is installed on the tool, then the furnace body is closed, gradient heating is conducted, nitrogen is introduced for welding, and air cooling is conducted after welding is completed. Aiming at industrial pain points such as non-uniform high-frequency welding temperature and performance degradation of a non-welding area caused by integral heating of a tunnel furnace, a physical isolation and dynamic temperature control fusion technology is developed, and accurate temperature control of the welding area is realized.

The embodiment of the invention provides a thermotechnical automatic production feeding device. The thermotechnical automatic production feeding device comprises an elevator and a feeding hopper fixedly connected to the surface of a conveying belt of the elevator. The covering part comprises a plurality of covering plates which are connected to the two sides of the elevator in a sliding mode and can synchronously move along with the feeding hopper, and the covering plates are used for covering the top of the feeding hopper in the lifting process of the feeding hopper. According to the feeding hopper, the covering component is arranged, and the covering plate of the covering component is located on the upper side of the feeding hopper in the lifting process of the feeding hopper and synchronously moves along with the feeding hopper, so that the effect of covering a coal mine in the feeding hopper is achieved, meanwhile, falling of coal briquettes and outward scattering of coal ash are prevented, and the working environment is optimized.

This invention relates to the field of hook tail frame processing technology, and discloses a hot-working fixture for hook tail frames, including a fixed arm, a fixed rod, and a support rod. The top end of the fixed rod is connected to the fixed arm. The fixed rod includes a left fixed rod and a right fixed rod vertically arranged on the left and right sides of the fixed arm. The interval between the left and right fixed rods is less than the inner length of the hook tail frame to be lifted. The left and right fixed rods can simultaneously pass through the inner cavity of one hook tail frame to be lifted, and the bottom of both the left and right fixed rods is provided with a protrusion to prevent the support rod from falling. The support rod is detachably mounted on the protrusion and can contact the bottom surface of the hook tail frame to be lifted to bear weight and support the hook tail frame. This invention has a simple overall structure, is easy to use, and can stably lift a large batch of hook tail frames at a time, which helps to improve the efficiency of hot working.

This invention belongs to the field of hot processing technology of rare earth iron-chromium-aluminum steel coils, specifically relating to a production method for preventing edge cracking of hot-rolled steel coils containing rare earth iron-chromium-aluminum, including: (1) transferring the rare earth iron-chromium-aluminum slab to a heating furnace for heating by using a hot-loading method; (2) rough rolling the rare earth iron-chromium-aluminum slab, with 7 passes and a deformation rate of 12%-16%, 18%-22%, 18%-22%, 24%-28%, 26%-30%, 28%-32%, and 30%-34% for each pass; (3) after rough rolling, heating compensation is applied to the edge of the intermediate slab; (4) after finishing rolling and coiling, a hot-rolled steel coil containing rare earth iron-chromium-aluminum is obtained. The production method of the present invention for preventing edge cracking of hot-rolled steel coils containing rare earth elements (iron, chromium, and aluminum) significantly reduces the problem of edge cracking in hot-rolled steel coils containing rare earth elements (iron, chromium, and aluminum). It can produce hot-rolled steel coils with a rare earth content of 0.02%-0.12%, a thickness of 3.0-3.5 mm, and a width of 1000-1300 mm, preventing edge cracking of hot-rolled steel coils, reducing the risk of breakage after uncoiling, and ensuring the smooth progress of subsequent production.

The present disclosure relates to a jaw of a drill chuck, a drill chuck, and a method for assembling the jaw. The jaw includes a jaw body and a jaw cutting edge band. One side of the jaw body has a clamping inclined surface that extends obliquely with respect to the axis of the jaw body. A jaw groove is formed in the clamping inclined surface. The jaw cutting edge band can contract during cooling to enter the jaw groove and, after the cooling contraction state is restored, is in interference fit with the jaw groove, so that the jaw cutting edge band can be reliably installed in the jaw groove on the jaw body without hot working and without additional connecting parts such as welding agents, and thermal deformation of the jaw can be avoided.

The present invention relates to a maraging steel suitable for hot working tools, the steel consisting of the following in weight % (wt. %): C<0.08, Si 0.1-0.9, Mn<2, Cr 4.0-6.5, Ni 2.0-5.0, Mo 3.5-6.5, Co 2.0-5.5, Cu<4.0, Nb<0.1, V<0.1, Ti<0.1, Fe and impurities as the balance.

Provided is a hot work tool steel powder for laminate molding, which is capable of molding a hot work tool steel laminate molded article having excellent crack resistance during molding. A hot work tool steel powder for laminate molding and a hot work tool steel laminate molded article containing, in mass%, 0.10%-0.25% of C, 0.01%-0.5% of Si, 1.5% or less of Mn, 3.0%-6.0% of Cr, 2.0%-3.5% of Mo and / or W based on the relational expression of (Mo + 1 / 2 W), 0.3%-0.7% of V, 0%-0.5% of Ni, 0%-0.25% of Cu, and the remainder being Fe and unavoidable impurities, and satisfying formula (1): C + Si / 30 + (Mn + Cr + Cu) / 20 + Ni / 60 + (Mo + 1 / 2 W) / 15 + V / 10 < = 0.75.

The invention relates to the field of steel processing, and discloses a method for reducing transverse and longitudinal performance difference of an ultrahigh-strength steel material. The method comprises the steps that a cast ingot with set components is smelted through vacuum induction, and then a vacuum consumable ingot is manufactured; the steel ingot is heated and subjected to heat preservation till primary carbide is fully redissolved; extruding the steel ingot until the ratio of the perimeter to the height of the cross section of the steel billet reaches a preset ratio, and reshaping; the blank is subjected to primary hot rolling alternately with the length direction and the width direction as the rolling direction; and the blank is subjected to secondary hot rolling alternately with the length direction and the width direction as the rolling direction till the thickness of the blank meets the requirement. According to the method, the alloy components and the hot working technology of the ultrahigh-strength steel are comprehensively regulated and controlled, the transverse and longitudinal performance difference of the ultrahigh-strength steel is effectively reduced, the average value ratio of the transverse and longitudinal tensile strength of the ultrahigh-strength steel is 99% or above, the average value ratio of the transverse and longitudinal yield strength of the ultrahigh-strength steel is 98% or above, and the average value ratio of the transverse and longitudinal U-opening impact toughness of the ultrahigh-strength steel is 100% or above.