1157 results about "Slow cooling" patented technology

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 relates to a 1200MPa-grade high-strength tool steel wire rod and a manufacturing method thereof, after V-containing chemical components are designed, rolled and spun into a wire rod, the wire rod is subjected to online molten salt isothermal quenching treatment, and the wire rod is controlled to enter a bainite phase region from a high-temperature austenite state at a cooling speed greater than or equal to 32 DEG C / s; the steel wire rod with a microscopic structure comprising tempered bainite and ferrite is prepared through isothermal tempering, toughening and destressing treatment, carbide precipitation control and roller way cover opening and slow cooling, so that generation of deteriorated structures such as martensite can be avoided, the structure state can be effectively adjusted, strong plasticity matching of the steel wire rod is achieved, and the service life of the steel wire rod is prolonged. And the tensile strength is 1120-110MPa, the percentage reduction of area is 63-67%, and the steel is suitable for the application fields of manufacturing 1200MPa-grade high-strength tool steel and the like, and is favorable for being directly processed into tool parts after being subjected to cold processing molding.

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 high-strength complex-phase hot-rolled wire rod for a 2200MPa-grade stranded wire and a manufacturing method of the high-strength complex-phase hot-rolled wire rod, and the manufacturing method comprises the following steps: rolling and spinning to form a wire rod by adopting a high-hardenability component design, and then carrying out online molten salt mixed phase region quenching isothermal treatment, so that the wire rod is firstly subjected to front-section molten salt treatment and enters a bainite and pearlite phase region from an austenite state; the method comprises the following steps: carrying out high-temperature treatment on austenite to promote part of austenite to be converted into bainite and sorbite, carrying out later-section molten salt treatment, increasing the molten salt temperature, reducing the molten salt circulation amount, promoting unconverted retained austenite to be decomposed and converted into bainite and sorbite, carrying out isothermal tempering, and finally carrying out slow cooling through a roller way, the hot-rolled wire rod with a microscopic structure comprising a complex phase structure composed of tempered bainite and tempered sorbite is prepared, the material cost can be reduced, the complex phase structure and the structure toughness can be regulated and controlled on line, the tensile strength is 1505-1555 MPa, the percentage reduction of area is 32%-37%, efficiency and energy consumption are both considered, off-line heat treatment is avoided, and high-efficiency production of stranded wires is promoted.

The invention discloses an automatic battery box welding device and a working method thereof, and relates to the technical field of battery box welding, the automatic battery box welding device comprises a conveying line, a preheating system, a welding system and a slow cooling system, the preheating system, the welding system and the slow cooling system are sequentially and adjacently arranged in the conveying direction of the conveying line, and the welding system comprises a clamping mechanism; the clamping mechanism can move flexibly and clamp and fix the frame body conveyed by the conveying line. The working method comprises the first step of placing the frame body, the second step of preheating, the third step of fixing, clamping and welding and the fourth step of slow cooling. The frame main body of the battery box body is preheated through the preheating system, and the frame main body of the battery box body is subjected to heat preservation and slow cooling through the slow cooling system; and a hot gas recovery system is arranged between the preheating system and the slow cooling system, so that waste gas in the preheating system is recycled.

The invention relates to a high-strength complex-phase hot-rolled wire rod for a 2360MPa-grade stranded wire and a manufacturing method of the high-strength complex-phase hot-rolled wire rod. After a Mo-V high-carbon component system is rolled and spun into a wire rod, the wire rod is subjected to on-line molten salt weak quenching toughening treatment, so that the wire rod is subjected to front-section molten salt treatment to be quickly cooled, enters a bainite and sorbite mixed phase region from an austenite state, and is subjected to high-temperature heat treatment to form a high-strength complex-phase hot-rolled wire rod; the method comprises the following steps: firstly, carrying out heat treatment on residual austenite to form a structure mainly comprising bainite and sorbite, then carrying out later-section molten salt treatment, increasing the temperature of molten salt, promoting decomposition and conversion of unconverted residual austenite into sorbite, carrying out isothermal tempering, and finally, carrying out roller way slow cooling to prepare a hot-rolled wire rod of which the microscopic structure comprises a complex-phase structure consisting of tempered bainite and tempered sorbite, the method has the advantages that the structure toughness can be regulated and controlled on line, the tensile strength is 1574-1627 MPa, the percentage reduction of area is 28-33%, the mechanical property fluctuation is reduced, the material cost and the production efficiency are both considered, the ultra-high-strength stranded wire can be produced without off-line heat treatment, and the wire breaking risk is reduced.

The invention relates to the technical field of high-performance ceramic preparation, in particular to a partial pressure sintering method of a silicon nitride ceramic chip, which comprises the stages of charging, negative pressure degreasing, partial pressure sintering, pressure sintering and rapid cooling: during charging, charging a green body containing a silicon nitride raw material and Y2O3 and MgO auxiliaries into a furnace, and exhausting air; in the negative-pressure degreasing stage, low-pressure nitrogen and staged heating are used for promoting formation and volatilization of an auxiliary liquid phase; volatile matters are released through stepped nitrogen partial pressure in the partial pressure stage; in the pressurizing stage, gradient increase of pressure from low pressure to 35 bar is achieved through phase change buffering, high-temperature densification, ultra-high-temperature homogenization and slow cooling, and precise pressure control is achieved by combining dynamic pressure-static pressure mode switching; according to the method, the problems of cracking, uneven density and the like of a traditional process are effectively solved, the ceramic chip yield and the dimensional precision are improved, the microstructure and the mechanical property are optimized, the high-temperature applicability and the thermal property are enhanced, meanwhile, the use amount of auxiliaries is reduced, energy consumption is reduced, and practicability and economical efficiency are achieved.

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 preparation method of beryllium-copper alloy. The preparation method comprises the following steps: (S1) accurately weighing the following raw materials by mass: copper, beryllium, copper-yttrium alloy, copper-titanium alloy, copper-manganese alloy and nano ytterbium powder; (S2) the raw materials are added into a vacuum induction furnace, the temperature is increased to 1400-1600 DEG C under the inert atmosphere, after the raw materials are completely molten, a covering agent is spread on the melt, smelting, standing and slagging-off are conducted under the stirring condition, the melt is poured into a mold under the condition of 1100-1200 DEG C, and a beryllium copper alloy ingot is obtained; and (S3) the beryllium-copper alloy ingot is subjected to face milling treatment, solution treatment, cold machining deformation treatment and aging treatment in sequence, and the product beryllium-copper alloy is obtained. A small amount of metal elements are added, aging treatment is carried out under the microwave condition, and then slow cooling is carried out at the constant cooling rate, so that the overaging phenomenon can be remarkably inhibited, the hardness of the alloy is improved, and meanwhile, the mechanical property, especially the stress relaxation resistance, is also improved.

The invention is suitable for the technical field of aluminum alloy welding, and provides an aluminum alloy pipeline welding device and a welding method thereof.The aluminum alloy pipeline welding device comprises a welding unit and a slow cooling unit; the welding unit comprises a supporting frame, a displacement air cylinder, a displacement sliding block, an electric telescopic rod, a rotating disc, a sliding rail, an electric sliding block, an adjusting piece and a welding gun. The slow cooling unit comprises a fixing plate, a fixing block, a telescopic air cylinder, a telescopic plate, an arc-shaped rail, an electric arc block, a heating plate and an electric heating wire. The four to-be-welded areas of the aluminum alloy pipeline and the flange are divided, the four to-be-welded areas do not make contact with spot welding on the formal welding path, welding operation continues after impurities on the surface of the spot welding area are ground through the angle grinder, and therefore the strength and the sealing performance of a welding seam are improved, and the welding efficiency is improved. And the welding quality of the welding position of the aluminum alloy pipeline and the flange is improved.

The utility model relates to the technical field of welding pipe devices, and in particular to a rapid cooling device for a welding pipe machine. Its technical solution includes a side ring, a welding machine, a motor, a second sleeve ring, a welding gun and a screw. The outer wall of the side ring is provided with support rods distributed in an annular array, and the support rod is provided with a first sleeve ring and a second sleeve ring. The first sleeve ring is provided with a screw hole, and a screw is rotatably inserted in the screw hole. A clamping block is provided at the lower end of the screw. A motor is provided between the support rods. The outer side of the second sleeve ring is connected to a ring seat, and the inside of the ring seat is respectively penetrated by a first sleeve ring and a second sleeve ring. A conveying pipe is inserted in the first sleeve ring, and a nozzle is provided at one end of the conveying pipe, and a welding gun is inserted in the second sleeve ring. The utility model uses the self-rotating second sleeve ring to perform annular self-propelled welding on the clamped pipe, and the end face after welding is cooled by the automatically transported cold medium, which solves the problem of slow natural cooling and reduced welding surface quality.

The invention relates to a small-specification low-chromium high-carbon steel wire rod and a preparation method thereof. The diameter of the wire rod is # imgabs0. Chemical components of the wire rod comprise 0.79%-0.84% of C, 0.20%-0.30% of Si, 0.70%-0.90% of Mn, smaller than or equal to 0.020% of P, smaller than or equal to 0.020% of S, 0.18%-0.23% of Cr, smaller than or equal to 0.0040% of O, smaller than or equal to 0.0050% of N and the balance Fe and impurities. The production technology process mainly including KR molten iron pretreatment, converter smelting, LF refining furnace smelting, continuous casting, controlled rolling and controlled cooling and heat preservation channel slow cooling is adopted, the sorbite rate of the product reaches 90% or above through the measures of Cr micro-combination, the stelmor cooling technology and the like, the requirements of the high strength and the drawing technology of the wire rod are met, and the product quality is improved. The problems that in the wire rod production process, due to the fact that abnormal structure martensite appears, the strength is high, and brittle failure is caused in the wire rod drawing process are solved.

The invention relates to the technical field of ceramic intelligent manufacturing, in particular to a ceramic firing process thermal deformation intelligent prediction and self-adaptive temperature precise regulation and control system, which comprises a multi-source sensing module (a thermal infrared camera array, a temperature sensor, a laser displacement meter and a powder characteristic analyzer); a hybrid prediction model (a space-time convolutional neural network constrained by a physical mechanism); and the self-adaptive temperature control actuator comprises a partitioned burner group, a quenching / slow cooling pipeline and a gas-air volume decoupling controller. According to the scheme, through a multi-mode perception-hybrid modeling-dynamic optimization full-process closed-loop architecture, the single-point technical limitation of existing patents is broken through, and the zero-defect precise manufacturing target of ceramic firing is achieved.

The invention relates to a production method of a large-thickness high-toughness ultrahigh-strength F890 maritime work steel plate. The steel plate comprises the following chemical components in percentage by mass: 0.10%-0.16% of C, 0.20%-0.30% of Si, 1.00%-1.40% of Mn, less than or equal to 0.005% of P, less than or equal to 0.0010% of S, more than or equal to 0.060% of Al, less than or equal to 0.005% of Nb, 0.03%-0.05% of V, less than or equal to 0.004% of Ti, less than or equal to 0.60% of Cr, 1.00%-1.50% of Ni, less than or equal to 0.30% of Cu, 0.20%-0.60% of Mo, 0.0010%-0.0020% of B, 0.0005%-0.0030% of Ca, less than or equal to The technological process comprises the steps of KR desulfurization pretreatment, converter treatment, LF refining, RH vacuum degassing, thick plate blank continuous casting, continuous casting blank covering and slow cooling, casting blank heating, rolling, steel plate offline covering and slow cooling, double quenching and tempering. The F890 ultrahigh-strength maritime work steel plate with the thickness smaller than or equal to 100 mm is finally obtained, and the mechanical property of the F890 ultrahigh-strength maritime work steel plate meets the requirements of the nine national classification society

The invention discloses a production method of a 15CrMoR steel plate for rare earth microalloying hydrogen-contacting equipment with excellent high-temperature performance. The production method comprises the steps of KR desulfurization, converter smelting, LF refining, RH refining, continuous casting, slow cooling in a heat preservation pit, heating, rolling, cooling, hot straightening, shearing, flaw detection, normalizing and tempering. The steel comprises the following chemical components in percentage by mass: 0.15-0.17% of C, 0.20-0.30% of S i, 0.50-0.60% of Mn, less than or equal to 0.012% of P, less than or equal to 0.005% of S, 0.019-0.029% of Al s, 0.9-1.1% of Cr, 0.50-0.60% of Mo, less than or equal to 0.0020% of Ce, less than or equal to 1.5 ppm of H, less than or equal to 0.0040% of O, less than or equal to 0.0060% of N and the balance of Fe. And the balance of iron impurities. A normalizing and tempering heat treatment process is adopted, and a low-carbon component design is adopted to ensure that the steel plate obtains excellent high-temperature performance and welding performance.

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 a high-carbon high-alloy grinding ball steel rolling internal damage control method, and belongs to the technical field of metal material rolling machining. Comprising the following steps that high-carbon high-alloy grinding ball steel billets are subjected to high-temperature diffusion homogenization treatment and then subjected to staged temperature control rolling, the initial rolling temperature in the blooming stage is 1020-1080 DEG C, the single-pass reduction rate is 6-10%, the pass interval is larger than or equal to 20 seconds, the total reduction rate is 40-80%, and the core peak temperature is controlled to be smaller than or equal to 1150 DEG C; the finish rolling temperature is 800-850 DEG C; during rolling, atomized water is sprayed for dynamic cooling every 2-3 passes, and two-stage cooling (water cooling to 600-650 DEG C at 15-20 DEG C / s, and slow cooling to room temperature) is carried out after final rolling. According to the method, element diffusion, temperature rise inhibition and structure refinement are synergistically regulated and controlled, so that the core void ratio is reduced, the austenite grain size is larger than or equal to 8 grades, a uniform bainite and dispersed carbide composite structure is obtained, and the anti-fatigue performance of the grinding ball steel is remarkably improved.

The invention relates to a 1300 MPa-grade high-strength tool steel wire rod and a manufacturing method thereof, after a Cr-Nb-V medium carbon component design is adopted for rolling and spinning to form a wire rod, the wire rod is subjected to online molten salt micro-quenching tempering treatment, the wire rod is controlled to enter a lower bainite phase region from a high-temperature austenite state at a cooling speed greater than or equal to 31 DEG C / s, and a quenching structure mainly comprising quenching bainite is formed; the steel wire rod with a microscopic structure comprising tempered bainite and ferrite is prepared by carrying out isothermal tempering and toughening destressing treatment on a quenched structure and finally carrying out roller way slow cooling, so that the material cost can be properly controlled, the strength and plasticity matching of the steel wire rod is improved, the tensile strength is 1255-1305MPa, and the percentage reduction of area is 58-63%, so that the steel wire rod can be directly processed into a part after being subjected to cold processing molding, and the service life of the steel wire rod is prolonged. And tool steel production energy consumption, cost reduction and efficiency improvement are facilitated.

The invention discloses a crystallization process of o-chloro-p-nitroaniline, which comprises the following steps: feeding a material into a crystallization kettle to crystallize the o-chloro-p-nitroaniline, regulating and controlling the temperature in the kettle body in the crystallization process, cooling to a metastable region of the o-chloro-p-nitroaniline, preserving the heat in the metastable region for a first preset time length, and then cooling to a second preset time length; continuously cooling to a first temperature lower than the melting point of the o-chloro-p-nitroaniline, keeping the temperature at the first temperature for a second preset duration, continuously cooling to a second temperature, and outputting the material out of the crystallization kettle for filtration and separation; in the cooling process, the cooling speed in the kettle body is controlled to be 0.1-0.2 DEG C / min. According to the invention, the interior of the kettle body can be slowly cooled, and the cooling speed of each part in the kettle body can be more uniform, so that the crystallization purity and the product quality of o-chloro-p-nitroaniline are finally improved.

The invention discloses an alloy wire rod hot drawing cooling device, and relates to the technical field of wire rod hot drawing cooling devices, the alloy wire rod hot drawing cooling device comprises a hollow outer shell, a cooling clamping cylinder is horizontally arranged in the outer shell in a sliding mode, and the cooling clamping cylinder comprises a driving shell seat which is of a hollow structure and horizontally slides in the outer shell through a driving part; the cooling cavity base is composed of an upper clamping base and a lower clamping base, and when the upper clamping base and the lower clamping base are attached, the alloy wire to be cooled is clamped. The temperature of the wire body is reduced in a continuous three-stage cooling mode, and compared with a rapid cooling mode in the prior art, the continuous three-stage cooling mode is changed into a slow cooling mode, namely, an open cooling mode is adopted in the first stage, and a clamping closed cooling mode is adopted in the second stage and the third stage; wherein in the cooling process of the second stage and the third stage, the cooling clamping cylinder synchronously moves along with the wire body after clamping the wire body, cooling sufficiency and continuity are guaranteed, and the wire body can be prevented from generating cracks in the clamping state.

The invention belongs to the field of dies, and particularly relates to a cam cover die-casting die with a spiral cooling structure, a die table mechanism comprises a lower die table and an upper die table which are combined, and a lower die core and an upper die core which are matched with each other are arranged in the lower die table and the upper die table; the pouring mechanism comprises a pouring end seat arranged on the upper mold table, a pouring channel penetrating through the upper mold core is formed in the pouring end seat, and the other end of the pouring channel penetrates into a closed cavity of the lower mold core and the upper mold core; the track mechanism comprises a track table arranged on the outer side of the cavity; the multi-layer structure of the spiral pipe is in direct contact with the outer wall of the cavity, the spiral flowing path of a cooling medium is combined, the heat exchange area and cooling uniformity are increased, the casting deformation risk is reduced, a temperature sensing end base integrated temperature sensor monitors the temperature of the cavity in real time, and the flow of the cooling medium is dynamically adjusted in cooperation with a deformation piece driven by an air bag piece. And intelligent control of slow-cooling anti-cracking in a high-temperature area and rapid-cooling shaping in a low-temperature area is realized.

The invention discloses a method for manufacturing an injection-molded receiver net plastic part, which comprises the following steps of: heating and melting a polymer melt through a feeding structure, injecting the polymer melt into a mold to obtain the receiver net plastic part, and quickly cooling a sound outlet hole of the receiver net plastic part by adopting preset high-temperature circulating liquid cooling in a first cooling stage through dynamic cooling treatment; the rigidity of the micropore area is effectively improved, the problem of micropore structure deformation caused by non-uniform cooling is reduced, polymer melt in the sound outlet hole area can be cured in time through rapid cooling, excessive shrinkage is avoided, and therefore the total shrinkage rate of the sound outlet hole is remarkably reduced; and in the second cooling stage, cold air is sprayed at the preset low temperature to slowly cool the outer surface of the receiver net plastic part, the toughness of the outer layer structure is enhanced, the differentiated cooling modes are accurately regulated and controlled according to different requirements of the inner and outer structures of the receiver net plastic part, uniform distribution of the shrinkage rate in the whole cooling process is achieved, and the product quality is improved. The problem that the overall shrinkage rate is too large due to a traditional cooling mode is effectively solved.

The invention discloses a wire rod for 2000MPa-level prestressed steel with the large specification of 15mm and a preparation method of the wire rod, and belongs to the technical field of metal material preparation and metal pressure processing. The invention aims to develop a 15mm large-specification high-performance prestressed steel wire rod with a novel component system and a matched production process thereof, the tensile strength of the wire rod is greater than or equal to 1200MPa, and the percentage reduction of area (after aging) is greater than or equal to 30%; the product can be used as a large-specification high-strength high-speed rail plate prestressed steel wire and a 1960-2000MPa-grade high-performance prestressed steel wire and a steel strand. According to the method, the technological process of molten iron pretreatment, converter smelting, LF refining, RH refining, square billet continuous casting, casting billet slow cooling pit slow cooling, casting billet heating, high-pressure water descaling, controlled rolling and controlled cooling and PF line heat preservation channel slow cooling and a complete and controllable production process system are adopted; and the harsh requirements of large-size high-performance prestressed materials of modern important projects on the performance of the wire rod are met.

The invention discloses a heat treatment process of an alloy drill bit, which belongs to the field of alloy and comprises the following steps: S1, after the alloy drill bit is primarily machined and formed, carrying out vacuum pretreatment, heat preservation and heating; s2, the drill bit is rapidly transferred into a sectional temperature control carburizing furnace to be subjected to main carburizing treatment, the temperature is controlled between 930 DEG C and 960 DEG C, the carburizing time ranges from 3 hours to 4 hours, and the carburizing depth is controlled between 0.3 mm and 0.6 mm; s3, after carburizing is completed, subarea multi-speed cooling is carried out, quenching is carried out for 20 seconds at the temperature of 850 DEG C or above, controlled cooling is carried out for 60 seconds within the range of 550 DEG C to 650 DEG C, slow cooling is carried out for 80 seconds at the temperature of 200 DEG C or below, and a refined martensite complex phase structure is obtained; s4, after cooling is completed, double-section tempering treatment is carried out; and S5, performing ultrahigh-pressure static boriding diffusion treatment. The method has the beneficial effects that the processing uniformity, the structure stability, the wear resistance and the corrosion resistance of the alloy drill bit are effectively improved and the service life of the alloy drill bit is effectively prolonged by adopting staged temperature control, different cooling media and a directional quenching technology.

The invention discloses a long glass fiber compression molding method and system, and the method comprises the steps: laying a continuous glass fiber plate and a long glass fiber material ball in a mold cavity in a partitioned manner, and obtaining a positioned composite green body; local prepressing is applied to the interlocking area of the composite blank, a mechanical meshing structure is formed, and a prefabricated body with an interface interlocking structure is obtained; establishing a pressure distribution model according to the geometric characteristics of the product to obtain differentiated pressure parameter combinations; placing the preform in a heating mold, and applying pressure in stages according to the pressure parameter combination to obtain a semi-finished product without glass fiber exposure; and for the semi-finished product, under the state that the second pressure value is kept, rapid cooling is conducted on the flange and the corner area, slow cooling is conducted on the large face area, and a final product with the balanced internal stress is obtained. By utilizing the embodiment of the invention, the efficient synergy of the continuous glass fiber plate and the long glass fiber material block can be realized, and the mechanical property and the structural integrity of the product are improved.

The present application relates to a low-yield ratio 420MPa low-alloy high-strength steel and a preparation method, belonging to the technical field of steel manufacturing. In terms of mass fraction, the chemical composition of the low-alloy high-strength steel includes: C: 0.07% to 0.12%, Si: 0.10% to 0.40%, Mn: 1.60% to 1.80%, P: ≤0.015%, S: ≤0.010%, Alt: 0.020% to 0.060%, Nb: 0.03% to 0.05%, Ti: 0.01% to 0.03%, N≤0.005%, and matrix element Fe. The composition design gives full play to the solid solution strengthening of C and Mn and the fine grain strengthening and precipitation strengthening of Nb and Ti microalloys. At the same time, the continuous full annealing process does not require slow cooling treatment, which improves production efficiency and obtains low-cost, low-yield ratio 420MPa low-alloy high-strength (yield ratio ≤0.8) steel with both strength and excellent plasticity. This type of steel can withstand greater plastic deformation while meeting higher strength requirements without plastic instability, achieving the needs of lightweight automotive industry and excellent stamping integral forming of structural parts, and has broad application prospects.

The invention relates to the technical field of metallurgical materials, in particular to a production method of high-density large-specification high-carbon chromium bearing steel GCr15 round steel. During production of the high-density large-specification high-carbon chromium bearing steel GCr15 round steel, the steps of electric furnace smelting, LF furnace refining and VD vacuum degassing treatment, continuous casting, pit entering for slow cooling, rolling and slow cooling are sequentially carried out; during electric furnace smelting, carbon temperature dual control is conducted at the smelting end point, the C content ranges from 0.2% to 0.3%, and the tapping temperature ranges from 1600 DEG C to 1620 DEG C; during LF furnace refining and VD vacuum degassing treatment, the binary alkalinity in slag is 5-8, FeO + MnO is smaller than or equal to 0.5%, and the bottom blowing argon flow is controlled in a large-small-medium staged mode; during continuous casting, continuous casting operation is conducted at the constant pulling speed, the constant liquid level and the constant pouring temperature; during rolling, the compression ratio is greater than or equal to 15. The GCr15 round steel prepared through the production method is low in residual harmful element content and high in density.

The invention belongs to the technical field of steel forging, and particularly relates to martensite heat-resistant steel and a forging method. A forging process is optimized and improved, and after forging, furnace cooling of a forge piece is changed into the mode that the forge piece is rapidly cooled in air to 30-50 DEG C above the Ms transition point firstly, and then the forge piece is put into a furnace to be cooled along with the furnace. And coarse carbides generated during slow cooling of the material in a high-temperature area are avoided, then the material is put into a furnace to be cooled along with the furnace, and the forge piece is prevented from cracking during rapid cooling at the Ms point and below the Ms point. In the forge piece heat treatment process, the quenching charging mode is changed from furnace heating to temperature charging, the forge piece heating rate is increased, the superheat degree in the material austenitizing process is increased, the nucleation rate is promoted to be increased, and the grain size of the quenched forge piece is effectively increased. And the second tempering cooling mode is changed from air cooling to oil cooling. And the generation of second-class tempering brittleness in the tempering process is effectively avoided. A plurality of batches of forgings are produced according to the optimized process scheme, the impact performance tends to be stable, and the situation that the accidental impact performance is unqualified does not occur any more.