315 results about "Machinability" patented technology

The invention relates to the technical field of lathe numerical control, in particular to a lathe digital intelligent management method and system based on industrial visual analysis. The method comprises the following steps that multidirectional lathe workpiece monitoring is carried out based on a heterogeneous visual sensing array, and a theoretical lathe machining finished product is obtained; real-time lathe tool and workpiece interactive monitoring is carried out, and time sequence tool cutting state data are constructed; according to the time sequence cutter cutting state data, carrying out finished product comprehensive form deviation evaluation on the theoretical lathe machining finished product so as to obtain a machining form deviation evaluation result; and performing cutter cutting performance attenuation analysis according to the machining form deviation evaluation result to generate a dynamic machining parameter set of the lathe. The lathe management efficiency and the machining precision are improved through dynamic and real-time lathe machining parameter adjustment.

The invention relates to a high-quality non-quenched and tempered steel rectangular bloom for a crankshaft and a preparation method of the high-quality non-quenched and tempered steel rectangular bloom, and belongs to the technical field of non-quenched and tempered steel preparation. In order to improve the purity of molten steel for continuous casting and solve the problems of surface crack, composition segregation and uneven structure of the rectangular bloom of the steel for the non-quenched and tempered crankshaft, the invention provides a preparation method of the rectangular bloom of the steel for the high-quality non-quenched and tempered crankshaft, and the preparation method comprises the process steps of converter / electric furnace smelting, LF refining, VD / RH vacuum treatment and continuous casting. According to the method, the size and shape of the inclusions are controlled by taking strong deoxidation, uniform stirring, slag system refining and soft blowing time as the core, the fusiform MnS-shaped inclusions are obtained, and the cutting performance and the overall mechanical performance of the steel are remarkably improved. According to the method, continuous casting is carried out in a weak cooling and slow drawing mode, the surface of a casting blank is controlled to crack smoothly, the homogenization and the internal quality of the casting blank are improved, the quality of the non-quenched and tempered steel for the crankshaft is obviously improved, and a good base material is provided for rolling the crankshaft.

The present invention relates to the technical field of other processing of metals. Disclosed are a free-machining titanium material and a preparation process therefor. The free-machining titanium material comprises: a matrix component group and free-machining component groups, wherein at least one of the free-machining component groups is added to the matrix component group; the matrix component group comprises the following components in percentage by mass: 0-1.0% of Fe, 0-0.08% of N, 0-0.02% of H, 0-0.50% of O, 0-8.0% of Al, 0-15.0% of V, and the balance being titanium and inevitable impurities; and the free-machining component groups are an RE element and S element group, a Cu element and S element group, a Zr element group, a C element group, a B element group, and an Mg element group, respectively. The preparation process involves producing the described free-machining titanium material by using any one of the following three methods: vacuum arc remelting, vacuum floating melting, and powder metallurgy. The present invention solves the technical problem of how to further improve the machinability of titanium materials.

The invention relates to the technical field of state monitoring of numerical control machine tools, in particular to an embedded monitoring method for cutter wear of a numerical control machine tool. The method comprises the following steps: performing embedded monitoring and synchronous multi-modal data acquisition and preprocessing on a tool in a machining process to form a real-time working condition data frame queue; cutting effective interval data interception is carried out on the real-time working condition data frame queue to obtain an effective cutting data sequence; performing current and cutter feeding rate discretization processing on the effective cutting data sequence to form an energy-effect reference fingerprint; extracting an expected healthy feed rate from the energy-effect reference fingerprint; and performing performance deviation absolute amount calculation according to the expected healthy feed rate, and performing cutting performance attenuation analysis to obtain the cutting performance attenuation degree. According to the method, a complete process from detection to parameter adaptive closed-loop control is realized on a resource-limited embedded system, so that the service life of a cutter is prolonged, the machining quality is guaranteed, and the production efficiency is improved.

This invention provides a copper alloy and its preparation method. The copper alloy has the following mass percentage composition: Ni: 0.5–2.0 wt%, S: 0.3–0.8 wt%, P: 0.1–0.3 wt%, Sn: 0.1–0.2 wt%, Si: 0.05–0.2 wt%, with the balance being Cu and unavoidable impurities. The microstructure of the copper alloy contains Cu₂S particles. This invention designs the composition and microstructure of the copper alloy, particularly controlling the content range of Ni, P, and Si elements to give the material high strength and high conductivity. Furthermore, the addition of S element forms Cu₂S particles, thereby improving the material's machinability and facilitating its fabrication into connector components.

The thin-gauge ultrahigh-strength non-oriented silicon steel comprises the following chemical components in percentage by mass: less than or equal to 0.002% of C, 3.1%-4.0% of Si, 0.3%-0.7% of Mn, less than or equal to 0.01% of P, less than or equal to 0.001% of S, 0.5%-1.2% of Als, 0.01%-0.08% of Sn, less than or equal to 0.002% of N, less than or equal to 0.001% of Ti, less than or equal to 0.002% of Nb, less than or equal to 0.002% of V and the balance of Fe and inevitable impurities, and Sieq is equal to [wSi] + 2 [wAl]-0.5 [wMn]. According to the technical scheme, trace alloy elements do not need to be added, the alloy smelting difficulty can be reduced, the smelting production cost is saved, meanwhile, the means of increasing deformation structures and improving the content of silicon, aluminum and manganese elements are adopted, and the material has the advantages of being high in strength, high in electromagnetic performance and excellent in machinability at the same time.

The invention discloses a material cutting performance evaluation method, device and equipment and a medium, and the method comprises the steps: controlling a milling cutter of a milling machine to mill a to-be-tested material according to preset milling parameters in a feeding direction perpendicular to the to-be-tested material under the condition that a test state is satisfied between fixed equipment and the to-be-tested material, so that a milling surface is formed on the to-be-tested material; controlling the force measuring equipment to monitor the actual milling force applied to the to-be-measured material by the milling cutter in the milling process; roughness detection equipment is controlled to detect the milling face, and the actual roughness is obtained; and evaluating the cutting performance of the to-be-tested material according to the actual milling force, the actual roughness and a preset index. Therefore, by integrating milling, real-time force measurement and surface roughness detection, a set of multi-index collaborative comprehensive evaluation system is constructed, and the cutting force and the machined surface quality can be quantitatively acquired and analyzed at the same time, so that the cutting machining performance of the material is simply, quickly, comprehensively and objectively reflected.

Provided are a lithium disilicate glass-ceramic green body, a preparation method therefor, and a use thereof. The lithium disilicate glass-ceramic green body comprises a lithium disilicate main crystal phase, crystal size in the lithium disilicate glass-ceramic blank being between 50 and 400 nm, and the proportion of the area of crystal grains having a length greater than 350 nm to the total area being less than 30%. The present disclosure, by means of controlling the internal crystal size of the lithium disilicate glass-ceramic green body to be below 400 nm, enables same to be directly machined without damaging the machining equipment, and combines the advantages of high strength, machinability and direct coloration. This can reduce the waiting time for patients to receive dental restorations, solve the problem of patients being unable to know the color of all-ceramic dentures before fabrication, and overcome a bottleneck for all-ceramic denture restoration materials for same-day delivery. It has great significance for achieving preoperative color matching and rapid restoration in clinical practice.

The present invention relates to a graphite steel having excellent machinability, and a manufacturing method therefor, and more specifically, to a calcium-containing graphite steel having machinability superior to that of normal free-cutting steel and a manufacturing method therefor.

The invention discloses a method for evaluating the machinability of sulfur-containing free-cutting steel. The method comprises the following steps: (1) testing the hardness of a section; (2) assigning hardness test data; (3) grade evaluation of sulfide inclusions; and (4) comprehensive assignment calculation is conducted, specifically, the product of the hardness absolute value grade assignment, the hardness standard deviation grade assignment and the sulfide inclusion grade assignment serves as the comprehensive assignment, the turning performance of the materials is sequenced according to the comprehensive assignment, and the smaller the comprehensive assignment is, the easier machining is. According to the evaluation method disclosed by the invention, before the sulfur-containing free-cutting cold-drawing bar is cut, the machinability of the bar is visually evaluated by detecting the hardness, the uniformity of the hardness and the distribution pattern of non-metallic inclusions and through assignment calculation, so that bar processing enterprises can be helped to estimate the processing efficiency and calculate the cost, and the processing efficiency of the bars is improved. And a guiding effect is achieved on enterprise production and operation.

A cutting tap is provided which suppresses breakage and wear of a blade during tapping and has high durability. In a nitriding treatment step (P2), a nitrogen diffusion layer in which nitrogen atoms contained in an atmosphere gas diffuse from the surface of a tool base material of the cutting tap under heating is formed, and then, in a honing treatment step (P3), an abrasive particle is made to collide with a cutting blade portion of the tool base material of the cutting tap to round the cutting blade portion and remove a blade tip. The cutting blade portion is made to have a thick nitrogen diffusion layer in advance by diffusion from a rear clearance face and diffusion from a front rake face, and the nitrogen concentration and hardness of the blade tip of the cutting blade portion are relatively high and mechanically brittle. Therefore, by removing the mechanically brittle blade tip, wear and breakage of the cutting blade portion of the cutting tap are reduced, and a tool performance capable of maintaining good cutting performance for a long period of time can be obtained.

The present application provides a kind of big coil easy cutting steel and its production process, component: C≤0.09%, Si≤0.005%, Mn:0.90~1.65%, P:0.04~0.09%, S:0.30~0.50%, Al≤0.030%, N≤0.0060%, O≤0.0140%, the balance is Fe and inevitable impurities.Compared with prior art, the present application controls LF furnace refining process activity oxygen range, cooperates with suitable big coil production process parameters, including soaking temperature, soaking time, opening rolling temperature, coiling temperature, controls coiling temperature range=J±15℃, J=(4×Mn / S+LF activity oxygen)+800℃.In this temperature interval, the final product sulfide spindle is properly controlled when coiling.The final surface quality is excellent, the product rod sulfide spindle rate is high, C-shaped scrap accounts for more than 90%, and the cutting performance is excellent.

This invention relates to the field of alloy technology, specifically disclosing a microalloyed copper alloy tube and its preparation process. The copper alloy tube is composed of the following components by mass percentage: Ni 0.05%-0.15%, Sn 0.05%-0.15%, Fe 0.01%-0.1%, P 0.02%-0.04%, with the balance being Cu and unavoidable impurities. The mass ratio of Sn to Ni is controlled between 0.5 and 3. It possesses a single face-centered cubic α-phase crystal structure, with an isometric grain ratio ≥85% in the microstructure and an average grain size of 10-20 μm. The preparation process achieves a three-dimensional strengthening effect of solution treatment, precipitation, and grain refinement. The product exhibits a tensile strength of 250-270 MPa, an elongation after fracture ≥45%, and a yield strength ratio of 0.32-0.36, combining high strength, low yield strength ratio, excellent machinability, and corrosion resistance. It is energy-efficient and easily mass-produced.

The invention discloses a weather-proof heat-insulation light-weight luggage and a lightening process thereof. The weather-proof heat-insulation light-weight luggage comprises a luggage body, the luggage is provided with a luggage body and a luggage cover, and the luggage body and the luggage cover are opened / locked through a zipper structure; a lantern ring is arranged at the opening of the box body, the lantern ring is fixed on the box body through a rivet, the lantern ring is of an aluminum alloy-carbon fiber composite structure, the lantern ring is formed by wrapping a carbon fiber woven three-dimensional structure with aluminum alloy, the carbon fiber woven three-dimensional structure is provided with hollow holes, and a supporting part extends outwards from the intersection of carbon fibers; and a weather-proof coating is arranged on the surface of the lantern ring. The lantern ring is made into a composite structure, the light and high-strength carbon fibers are combined with the aluminum alloy with toughness and machinability, the performance of the lantern ring is improved, the weather resistance of the lantern ring is improved through the coating on the surface of the lantern ring, and the attractiveness of the lantern ring is improved.

The utility model relates to the technical field of grinding, in particular to an agglomerated abrasive wire product and a grinding tool, the agglomerated abrasive wire product comprises an installation base body layer and a grinding layer, and the grinding layer and the installation base body layer are of an integrated structure; the grinding layer is provided with a plurality of grinding material base bodies, each grinding material base body comprises grinding material aggregates and a brittle medium base body, and the brittle medium base bodies and the grinding material aggregates are of an integrated structure. The utility model mainly aims to provide an agglomerated abrasive wire product which aims to prevent grinding scraps from being adsorbed on the outer surface of agglomerated abrasives and among the agglomerated abrasives, maintain the cutting performance of the abrasives and improve the grinding quality and efficiency.

This invention discloses a method for preparing a large round billet for continuous casting of forged cold-rolled roll sleeves, comprising: controlling the composition system, wherein the chemical composition of the raw material steel is: C: 0.65-0.75%, Si: 0.25-0.40%, Mn: 0.35-0.50%, P≤0.020%, S≤0.020%, Cr: 1.90-2.10%, Ni: 0.30-0.45%, Mo: 0.20-0.40%, V: 0.05-0.10%; and controlling the continuous casting process parameters, wherein the superheat is controlled within a certain range. The casting temperature is maintained between 15 and 35°C, the casting speed is kept stable at 0.24 ± 0.01 m / min, the crystallizer water flow is controlled at 3700 L / min, and the secondary cooling water flow in the crystallizer is controlled at 0.12 L / Kg. During continuous casting, a 200 A / 2.5 HZ electromagnetic stirring of the casting flow and a 500 A / 1.2 HZ strong end electromagnetic stirring are used. The heat treatment process parameters for the continuously cast round billets are controlled as follows: red-charging annealing of the continuously cast round billets, furnace charging temperature ≥ 400°C, heating rate ≤ 100°C / h, holding at 730°C for ≥ 15 h, furnace cooling to 400°C, and air cooling upon exiting the furnace. This invention ensures the hardness and wear resistance of the cold-rolled roll sleeves while improving toughness and machinability, avoiding surface cracking and internal cracking of the roll sleeves during the casting and forging processes, ultimately achieving high-efficiency production and long service life of the roll sleeves.

The invention relates to the technical field of steel production, in particular to a steel plate for an intermittent drive motor, which comprises the following chemical components in percentage by mass: less than or equal to 0.003% of C, 0.50-1.50% of Si, 0.5-1.5% of Mn, 0.02-0.06% of P, less than or equal to 0.001% of S, less than or equal to 0.002% of N, 0.05-0.15% of Mo and 0.20-1.00% of Als. And the balance of Fe and inevitable residual elements. The electromagnetic performance requirement can be met, the mechanical strength machining performance can be considered, the operation efficiency and reliability of the intermittent drive motor are improved, and the production cost is reduced.

A crescent-edge hard alloy milling cutter and a parameter design method thereof relate to the technical field of milling cutter design. The crescent-edge hard alloy milling cutter includes a front cutter head, a peripheral blade portion, and a shank portion, where a plurality of crescent peripheral blades extending helically toward the front cutter head are provided on the peripheral blade portion; a plurality of crescent cutting blades are provided on the front cutter head; and the crescent cutting blade and the crescent peripheral blade are in arc transition in pairs. With the design of the crescent cutting blade and the crescent peripheral blade, the crescent-edge hard alloy milling cutter has excellent cutting performance. Moreover, the crescent cutting blade and the crescent peripheral blade are in the arc transition, ensuring smoothness of the milling cutter to cut a metal workpiece.

The invention provides a silver-nickel-titanium electric contact material and a preparation method thereof. By adopting a nickel-titanium alloy material as a main additive, the welding resistance of the electric contact material is improved while the good machinability of the material is maintained. NiTi is introduced as a main additive to be added into an Ag matrix to improve the fusion welding resistance of the material, meanwhile, a small amount of trace copper is also added to mainly improve the wettability of the material, and the C powder and the titanium carbide powder improve the fusion welding resistance of the material. In addition, a powder metallurgy process is adopted, material proportion is easy to control, process flow is short, and cost is low. The rapid plasma electric spark sintering speed is high, the time is short, and the material density is high.

The application provides a thick-gauge cutting blade steel 75Cr1 open flat and a production method thereof, compared with the prior art, the application optimizes a conventional transverse cutting plate production process, especially for thick-gauge 12-20mm, high-strength 75Cr1, by means of a hot coil direct sheath annealing intermediate process, plasticity is improved, and cutting property is improved; in the transverse cutting process, by means of ''small deformation straightening'' and a non-edge cutting process, excellent thick-gauge cutting blade steel 75Cr1 open flat is generated. The application judges whether the hot-rolled strip steel is subjected to sheath annealing before transverse cutting according to the size of the critical value Agt of the hot-rolled strip steel and the size of the critical value A 临 of fracture occurring in the straightening process, selects the sheath annealing process according to the need, and saves the cost. In addition, the annealing process designed in the application can improve the microstructure and performance of the product, so that the product performance of the thick steel plate meets the requirements.

A machining system includes: a machining device configured to machine a workpiece; an acquisition device configured to acquire composition information representing the chemical composition of the material of the workpiece; and a determination device configured to determine the machinability of the workpiece based on a determination model created by inputting the composition information, processing condition information including processing conditions preset according to the material and thickness, and a machining quality evaluation result obtained by actually machining based on the processing conditions, as teaching data and performing machine learning. The determination device is configured to input composition information acquired before the machining of a workpiece to be newly machined and processing condition information including processing conditions set in the machining device according to the material and thickness, as data for estimation, to the determination model, and output a determination result regarding machinability based on the processing conditions of the machining to be performed.

The invention discloses a process production method of a tin-phosphor bronze alloy, which is characterized in that the tin-phosphor bronze alloy comprises the following components in percentage by mass: 0.6-0.7% of Sn; the copper alloy comprises the following components in percentage by weight: 0.10-0.25% of P, 0.05-0.10% of Te, less than or equal to 0.10% of other impurity elements and the balance of According to the method, the rod material with the diameter phi of 12.5 mm is produced through 2000 kg horizontal continuous casting. The process route comprises the steps of rod material continuous casting, cold rolling, softening annealing, reverse drawing and peeling, reverse drawing and peeling, softening annealing, reverse drawing and peeling, reverse drawing, softening annealing and reverse drawing of a finished product. According to the process route, the organization structure of the material is converted into a compact cold drawing organization from a coarse as-cast organization. And due to the increase of the tellurium element, the machinability of the material is improved by 15%, and the tin-phosphor bronze material obtained through the process route is compact in structure, fine in grain, high in strength and excellent in comprehensive performance. The tensile strength Rm of the tin-phosphor bronze material is larger than or equal to 800 MPa, the ductility A is larger than or equal to 3%, the machinability is 80% or above, and the electric conductivity is larger than or equal to 14% IACS.

The invention provides a production process of a photovoltaic module and the photovoltaic module. The production process of the photovoltaic module comprises the following steps: drawing protofilaments; calendering and flattening the protofilament to form a first part, a second part and a third part; carrying out annealing on the flattened protofilament; plating a first material layer on the annealed protofilament to form a solder strip; the welding strip is rolled; a welding strip is unwound, and the welding strip is straightened and cut to form a welding strip unit; welding the welding strip unit and the battery piece; and packaging the adhesive layer, and laminating the first cover plate, the second cover plate, the adhesive layer and the battery piece. Therefore, in the production process of the photovoltaic module, the flattening treatment is added during precursor calendering, the characteristics that the precursor is good in ductility and good in machinability when not annealed can be utilized, the flattening treatment generally does not enable the precursor to be broken, and the welding strip manufacturing process risk and the product reliability risk can be greatly reduced. And the protofilament is directly tinned after forming the first part, the second part and the third part, the surface appearance of the solder strip is better than that of a conventional process, surface burrs are reduced, and the welding strength of the solder strip can be improved.

The invention discloses a free-cutting and highly conductive copper alloy. The mass percentages of the components of the copper alloy are as follows: Ni: 0.5-1.5%, P: 0.05-0.2%, Pb: 0.1-0.3%, Te: 0.05-0.5%, Co: 0.01-0.3%, Zn: 0.01-0.5%, and the balance is Cu. The number of Pb particles in the copper alloy is 4000-11000 per mm 2 The copper alloy has good cutting performance, high electrical conductivity and strong mechanical properties. The present invention also discloses a method for preparing the easy-to-cut and highly conductive copper alloy.

The application relates to a rapid air-cooling aluminum alloy cylinder cover heat treatment method and an aluminum alloy cylinder cover, which comprises sequentially performing solid solution treatment, rapid air-cooling quenching treatment and artificial aging treatment on an aluminum alloy cylinder cover casting to obtain the aluminum alloy cylinder cover; the rapid air-cooling quenching treatment comprises: cooling the aluminum alloy cylinder cover casting through air cooling, and the cooling speed between 430 DEG C and 260 DEG C is 7+ / -2 DEG C / min. The application utilizes air-cooling quenching, designs corresponding cooling speed, has little influence on strength and elongation, and better cutting performance. T6 uses water cooling, has no speed requirement, and the actually obtained strength and elongation are much higher, leading to poor cutting performance, great influence on mass production cost and efficiency. After the technology is adopted, the heat treatment process parameters are solidified, the performance detection result of the cylinder cover verified through multiple rounds of debugging is good, the stable and reliable method effectively avoids broken chip defects, abnormal tool wear or breakage, the tool has good broken chip effect, and waste loss and machining cost are reduced.

The application belongs to a kind of shell processing method, aiming at the technical problems of low machining precision and easy deformation during the processing of hemispherical shell, provides a kind of hemispherical shell and its processing method, by optimizing the structure shape of raw material blank, the material blank consumption is reduced by about 10%, in the processing process, the clamping position is close to the processing position by optimizing the process clamping step, so that the machining process can increase the rough machining cutting amount, and the clamping positioning can be repeated, the positioning accuracy is improved, the production process is easy to operate, according to the material and cutting performance of the hemispherical part, by using the processing technology and tooling, the machining deformation of the hemispherical part is greatly reduced, and the qualified rate of batch production is effectively improved.

The invention provides a high-conductivity free-cutting copper alloy material and a preparation method thereof, and belongs to the technical field of alloy smelting. The preparation method of the high-conductivity free-cutting copper alloy material comprises the following steps: (1) smelting: heating and melting cathode copper, and covering with crystalline flake graphite in the melting process; and boron-copper alloy deoxidation, high-purity tellurium and high-purity iron powder are added. A graphite bell jar is used for adding. The temperature is increased to 1200-1250 DEG C, and heat preservation is conducted for 15-30 min so that alloy elements can be homogenized; adjusting the furnace temperature to 1170-1190 DEG C, and casting into an ingot through a high-purity graphite mold; (2) hot extrusion forming; (3) pickling and hydraulic drawing; and (4) straightening and sizing to obtain the required copper alloy material. According to the copper alloy material, at the room temperature (25 DEG C), the conductivity is larger than or equal to 90% IACS, the machinability is 80% or above higher than that of an HPb63-3 material in the same state, and the tensile strength is larger than or equal to 350 MPa when the cold machining deformation is 50%.

Sawteeth are provided with sharp head portions and round head portions, the sharp head portions are higher than the round head portions, and tool bits are welded to the sharp head portions. The damping grooves are formed between any two sawteeth; first grooves are formed in the upper end faces of the tool bits, and second grooves are formed in the front side faces of the tool bits. A plurality of damping grooves are formed in the saw blade body, so that the toughness of the saw blade body is improved, and vibration is reduced; the first groove and the second groove are formed in the upper end face and the front side face of the tool bit, the section of the first groove and the section of the second groove are both in an arc shape, the angle of the front angle of the tool bit is increased through the second groove, the cutting edge of the tool bit is sharper, the cutting edge of the tool bit is in an arc shape through the first groove, cutting is facilitated, and therefore the cutting performance of the saw blade is improved.

The application discloses a manufacturing method of a hard surface lining plate which needs screw holes and deep hole machining. The method selects 42CrMo steel to forge the hard surface lining plate, and the hard surface lining plate is obtained through forging, normalizing, rough machining, flaw detection, quenching, semi-finishing, flaw detection, stabilization heat treatment, finishing and inspection in sequence. The hard surface layer is manufactured by using the hardenability and hardness gradient distribution of the steel. The finishing allowance is left on the deep hole side of the lining plate, and the high-hardness decarburized layer of the quenching and tempering heat treatment is machined away on the hard surface working side of the lining plate, so that the surface hardness of the lining plate is high and the hardness of the deep hole side is low, the service performance is ensured, and the machinability is ensured. The method overcomes the defects of the traditional hard surface lining plate screw hole and deep hole machining, reasonably arranges the machining allowance by using the hardenability and hardness gradient distribution change of the steel to avoid the hard surface layer, realizes the hard surface lining plate screw hole and deep hole machining, and ensures that the hard surface lining plate machining meets the process requirements.

The invention relates to the technical field of metal material preparation, in particular to a heat treatment process of a mining vertical chain connecting ring. The mining vertical chain connecting ring is made of 23MnNiMoCr54 steel, and the heat treatment process is controlled in a double-gradient tempering and charging mode. By means of the innovative double-gradient tempering technology, precise regulation and control over the microstructure of the material are achieved, the spheroidization rate of carbide is increased to 70% or above from 65% or below, and the machinability and the mechanical property basis of the material are effectively improved; and meanwhile, the depth of a surface decarburized layer is strictly controlled within 200 microns, the fatigue strength of the surface layer is greatly reserved, the hardness distribution of a final finished product is highly uniform and is stabilized within the range of HRC39-42, the range does not exceed + / -1, and a solid foundation is laid for performance consistency.