578 results about "Carburizing" patented technology

The invention provides an online detection and compensation method for local decarburization of a high-strength spring steel band, which comprises the following steps: arranging an oxygen content sensor in a continuous annealing furnace to monitor oxygen concentration in real time, and marking a potential decarburization risk section; scanning the risk section steel strip by adopting infrared thermal imaging, and generating a carbon distribution map to position a decarburization area; pulse laser heating is conducted on the decarburization area, and methane-argon mixed gas is introduced to achieve in-situ carburization; and finally, local thermal stress is eliminated through high-frequency induction heating. According to the method, decarburization risk dynamic early warning, defect accurate positioning, local efficient carbon supplementation and stress homogenization control are achieved, and the surface quality and fatigue performance of the steel strip are remarkably improved.

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 heat treatment method for optimizing a gear steel structure and refining grains, and belongs to the technical field of heat treatment process control. The method is particularly suitable for a production scene of cold forging gear parts such as three pin shafts; according to the method, a pre-normalizing or annealing heat treatment process with specific parameters is added after cold forging forming and before carburizing, so that an AlN precipitated phase in the steel forms segregation again at a grain boundary, the grain boundary is effectively pinned, and austenite grain growth is inhibited, and therefore the phenomenon of mixed crystals is avoided, the structure is refined, and the fatigue performance is improved. Experiments prove that after normalizing pretreatment at the temperature of 900 DEG C or above or annealing pretreatment at the temperature of 720 DEG C is adopted, the original cold forging mixed crystal area with the grain size of 0-4 grade can be increased to 7 grade or above, grains are uniform and compact, and the structure property is remarkably improved. The process parameters are clear, the flow is controllable, and the method is suitable for optimization and application of the batch gear steel heat treatment process.

The invention provides a Q890qE and Q420qE bridge steel flat butt joint combined welding method which comprises the following steps: step 1, grinding and derusting grooves of upper and lower asymmetric double-sided V-shaped joints to expose metallic luster; 2, preheating is conducted in an electric heating mode; 3, a solid welding wire CO2 gas shielded welding is adopted for backing welding of one weld joint on the upper V-shaped deep groove side; 4, welding seams are filled in the side of the V-shaped deep groove through submerged arc automatic welding, and the filling thickness is about 1 / 2 of the groove depth; 5, back gouging is conducted on the back face through carbon arc air gouging, and a carburized layer is polished and cleaned till metallic luster is exposed; 6, the V-shaped shallow groove is welded and filled; seventhly, the submerged arc automatic welding continues to weld the remaining weld joints of the V-shaped deep groove till the remaining weld joints are filled; and 8, postweld heat treatment is conducted. According to the method, a combined welding method of solid welding wire CO2 gas shielded welding bottoming, submerged arc automatic welding filling and capping is adopted, the problems of welding cold cracking and early joint breakage of the dissimilar bridge steel are solved by combining joint design, and the mechanical properties of a welding seam and a fusion area meet the standard requirements.

The present application relates to a kind of Nb-Ti microalloying Cr-Mn gear steel and its preparation method, the chemical composition of the Nb-Ti microalloying Cr-Mn gear steel, by mass percentage, including: C:0.15~0.25%, Si≤0.20, Mn:0.8~1.60%, P:≤0.025%, S:0.010~0.035%, Cr:1.00%~1.80%, Ni:≤0.25%, Cu:≤0.20%, Ti:0.01~0.03%, Nb:0.02~0.07%, B≤0.0005%, Al:0.01~0.04%, [O]:≤12×10 ‑4 %, [N]:0.005~0.010%, [H]:≤1.5×10 ‑4 %, the rest is Fe and inevitable impurities.The Nb-Ti microalloying Cr-Mn gear steel prepared by the application has good hardenability, end hardenability J9=40~45HRc, J15=35~40HRc, which is greatly improved compared with 20CrMnTiH;The gear grain is refined, and the grain size reaches more than 7 levels after carburizing at 960~980 ℃ for 8~10 h, and the strength and toughness and fatigue performance of the gear are significantly improved.

To provide a component that enables suppression of strength degradation in an excess carburized portion, including degradation of impact resistance and bending fatigue characteristics.SOLUTION: A vacuum carburizing steel containing, in mass%, C: 0.15-0.30%, Si: 0.70-1.20%, Mn: 0.90-3.00%, Cr: 0.50-1.50%, Mo: 0.10-1.00%, Al: 0.020-0.050%, Nb: 0.020-0.100%, and N: 0.0100-0.0300%, the balance being Fe and unavoidable impurities, wherein P and S among the unavoidable impurities satisfy P: 0.030% or less and S: 0.030% or less, and formulas A, B, C, and D: A: 0.12≤3[Al]+4[Nb]≤0.50, B: 0.20≤[N] / [Al]≤0.80, C: 5.0≤3[Si] / 0.5[Cr], D: 1.95≤-2[Si]+3[Mn]+[Cr]+2[Mo], are all satisfied.SELECTED DRAWING: Figure 1

The invention provides a heat treatment method for a wind power gear forge piece. The heat treatment method comprises the following steps that 1, after-forging waste heat temperature equalization is carried out; 2, segmented forced controlled cooling is carried out till the forge piece reaches a furnace entering window, and forced cooling is carried out on the forge piece; at least three temperature measuring points are arranged on the forge piece; 3, isothermal normalizing for the first time, wherein the forge piece is placed in an isothermal furnace; 4, low-temperature reaustenitizing is conducted, specifically, the forge piece subjected to the first isothermal normalizing is heated to 860-910 DEG C, heat preservation is conducted, and the forge piece is reaustenitized; 5, secondary isothermal normalizing is conducted, specifically, the forged piece obtained after austenitizing is cooled to 645-670 DEG C in a controlled cooling mode, and isothermal heat preservation is conducted; the forge piece is heated to 380-450 DEG C, heat preservation is conducted, then the forge piece is cooled to 200 DEG C or below along with a furnace, and the forge piece is taken out of the furnace for air cooling. According to the method, a uniform and refined ferrite and pearlite structure is obtained in the core of the large-section forge piece, the hardness is stabilized within the range of 165-185 HBW, and the subsequent carburizing and quenching distortion sensitivity is reduced.

The invention relates to a high-speed rail gear steel bar produced through a continuous casting and rolling process and a manufacturing method of the high-speed rail gear steel bar, and belongs to the technical field of metallurgy. The steel comprises the following chemical components in percentage by mass: 0.15 to 0.20 percent of C, less than or equal to 0.40 percent of Si, 0.50 to 0.90 percent of Mn, 1.50 to 1.80 percent of Cr, less than or equal to 0.025 percent of P, less than or equal to 0.025 percent of S, less than or equal to 0.30 percent of Cu, less than or equal to 0.005 percent of Ti, 0.02 to 0.05 percent of Al, 1.40 to 1.70 percent of Ni, 0.25 to 0.35 percent of Mo, 0.015 to 0.035 percent of Nb, less than or equal to 0.0030 percent of Ca, 0.0090 to 0.0150 percent of N, less than or equal to 0.0012 percent of [O], less than or equal to 0.0001 percent of [H] and the balance of Fe and inevitable impurity elements. A narrow hardenability bandwidth control technology is realized by establishing a hardenability prediction model, accurately controlling smelting components and uniformly controlling solidification components, and the hardenability bandwidth of the material is less than or equal to 4 HRC; the gear steel is subjected to high-temperature carburization at 980 DEG C for 4 h, and the grain size reaches the level 5 or above.

The invention relates to the technical field of metal material strengthening treatment, in particular to a micropitting-resistant wind driven generator gear carburizing and quenching composite strengthening process which comprises the following steps: S1, gear blank pretreatment and surface activation; s2, gradient carburizing strengthening treatment; s3, grain refinement annealing treatment; s4, step quenching strengthening treatment; s5, performing deep cooling and thermal cycle treatment; s6, directional tempering regulation and control treatment; s7, composite shot peening strengthening treatment is conducted; and S8, an antifriction composite film layer is deposited on the surface of the gear subjected to shot peening strengthening in the S7. According to the method, through a synergistic strengthening mechanism of gradient carburization, step quenching, structure regulation and control and surface functionalization, the residual stress distribution and tribological performance are optimized while the high surface hardness of the gear is kept, and the technical problems that in a traditional technology, the carburized layer is concentrated in stress, uneven in structure, single in surface performance and the like are solved.

The invention relates to 20MnCrS5 carburizing steel and a method for manufacturing carburizing steel parts. The 20MnCrS5 carburizing steel comprises 0.17%-0.20% of C, less than or equal to 0.25% of Si, 1.10%-1.40% of Mn, 1.00%-1.30% of Cr, 0.02%-0.05% of Al, 0.02%-0.04% of S, 0.1%-0.4% of Ni, 0.015%-0.03% of Nb, less than or equal to 0.08% of Mo, 0.1%-0.25% of Cu, less than or equal to 0.015% of P, less than or equal to 0.008% of N and the balance Fe and inevitable impurities. The method comprises the following steps: forging a part by using 20MnCrS5 carburizing steel; the forged part is subjected to pre-oxidation; the pre-oxidized part is subjected to vacuum carburizing treatment, and the carburizing temperature ranges from 950 DEG C to 1000 DEG C; and the carburized part is subjected to high-pressure gas quenching. The Nb element is added on the basis of traditional 20MnCrS5 steel, meanwhile, the content of Ni and the content of Cu are increased, the high-temperature carburizing technology and the follow-up cooling technology are improved, and therefore the problem that carburizing steel parts are prone to thermal deformation in the high-temperature carburizing technology is solved.

The invention discloses a method and equipment for calculating the carbon concentration in the vacuum low-pressure carburization process, and relates to the field of vacuum low-pressure carburization. The first strong carburizing process serves as a target strong carburizing process, the first strong carburizing concentration analytical formula serves as a target strong carburizing concentration analytical formula, and strong carburizing process calculation operation is executed, specifically, based on the carburizing state parameters, the carbon concentration of the target strong carburizing process is calculated through the target strong carburizing concentration analytical formula; after the strong carburizing process calculation operation is executed, the diffusion process after the target strong carburizing process serves as a target diffusion process, and diffusion process calculation operation is executed: based on the carburizing state parameters, the carbon concentration of the target diffusion process is calculated through a diffusion carbon concentration analytical formula; after the diffusion process calculation operation is executed, whether the target diffusion process is the last diffusion process is detected, and if yes, the calculation process is ended; the carbon concentration calculation accuracy and calculation efficiency can be improved.

The invention relates to the field of structure optimization of M50NiL high-temperature carburizing bearing steel for aero-engines, in particular to a treatment method for eliminating large-size carbides in a carburizing surface layer of rare earth M50NiL steel. The rare earth M50NiL steel comprises the following chemical components in percentage by mass: 0.11 to 0.15 percent by weight of C, 0.10 to 0.25 percent by weight of Si, 4.00 to 4.25 percent by weight of Cr, 4.00 to 4.50 percent by weight of Mo, 1.13 to 1.33 percent by weight of V, 3.20 to 3.60 percent by weight of Ni, 0.15 to 0.35 percent by weight of Mn, less than or equal to 0.02 percent by weight of the total amount of Ce and La, less than or equal to 0.01 percent by weight of P, less than or equal to 0.01 percent by weight of S and the balance of Fe. After carburizing treatment and performance heat treatment are conducted on the sample meeting the component requirements, the sample is treated for a short time only through the surface deformation technology, the number density of large-size carbides on the carburized surface layer can be effectively reduced, the size distribution uniformity of the carbides on the carburized surface layer is improved, and the wear resistance of the material is remarkably improved; and the performance requirements of the bearing for the current aero-engine are met.

The invention discloses a novel carbonitriding process for a bearing part. The novel carbonitriding process comprises the following steps: heating the bearing part in a carburizing furnace in a nitrogen protection state; the atmosphere of the replacement carburizing furnace is carbonitriding atmosphere; and carbonitriding and quenching the bearing part in a carburizing furnace under the atmosphere of methanol, propane and ammonia gas. According to the novel carbonitriding process for the bearing part, the phenomena that the surface of a product is oxidized and the color and luster are poor during treatment of a conventional atmosphere carbonitriding process are solved.

The invention discloses a method and a device for measuring the internal hardness of a carburized and quenched gear. The core of the method is that a segmented measurement strategy is adopted: in a first hardness gradient change area close to the surface, rapid positioning is carried out through a coarse adjustment mode; and in a second gradient change area close to the center, switching to a fine adjustment mode to carry out precise mobile positioning. By measuring hardness values of a series of radial points, a distribution curve is drawn, and the effective hardened layer depth is determined according to a fixed standard value or a calculated value based on the core hardness. The measuring device is provided with a gear shifting mechanism which can drive the duplicate gear to be meshed with the coarse adjustment gear or the fine adjustment gear, switching of different transmission ratios is achieved, and therefore the detection platform is driven to achieve a coarse displacement mode and a fine displacement mode. The problem that efficiency and precision of a traditional measurement method are difficult to consider at the same time is effectively solved, and the reliability of the result is ensured through a systematized anomaly review process.

The invention relates to the field of materials and processes for automobile parts, in particular to a homogenization evaluation method for hardenability of Ti-containing carburizing steel and application. According to different specifications and different looseness and segregation levels of the round steel, sampling regulation is carried out on the center part and the center part of the section of the Ti-containing carburizing steel round steel, and the hardenability and the hardenability bandwidth of the carburizing steel can be more truly reflected. When the hardness of the tail end hardenability sample is detected, two surfaces equidistant from the circle center of the section of the round steel are detected, a telecentric surface far away from the circle center of the section of the round steel and a proximal surface close to the circle center of the section of the round steel are detected, and compared with the current national standard, the detection result is more scientific and accurate. The method can be applied to almost all carburized steel bars with large component fluctuation, the uniformity is truly reflected, technicians can select raw materials with proper hardenability bandwidth to be applied to shaft gear parts with different size characteristics and using performance requirements, and the application prospect is very wide.

The present invention relates to a method for improving the mixed crystal structure of a 17CrNiMo6 material. The method comprises the following steps: S1, placing a forging in a heating furnace, heating it to 930-950°C, and then holding the temperature for 4-5 hours; S2, normalizing and air-cooling the forging after holding the temperature to 600-620°C, placing the forging again in the heating furnace and isothermally tempering and holding the temperature at 530-560°C for 4-5 hours; S3, placing the forging after tempering and holding the temperature in a heating furnace, raising the temperature of the heating furnace to 850-860°C and holding the temperature for 2-3 hours; S4, normalizing and air-cooling the forging after holding the temperature to 600-620°C, placing the forging again in the heating furnace and isothermally holding the temperature at 530-560°C for 4-5 hours; and S5, air-cooling the forging to room temperature, machining the forging, and then carburizing and quenching the forging. The method for improving the mixed crystal structure of 17CrNiMo6 material of the present invention can effectively improve the mixed crystal situation of 17CrNiMo6 material and ensure the stability of the 17CrNiMo6 material after it is made into products.

This invention relates to a wear-resistant shovel blade for engineering machinery and its preparation method, belonging to the field of engineering machinery parts manufacturing technology. The specific preparation method involves: after rolling, quenching, and high-temperature tempering, the shovel blade material undergoes carburizing treatment using ion plating. Then, a W transition layer and a WTiTaB boride gradient coating with varying composition are prepared using magnetron sputtering. This invention combines the WTiTaB boride gradient coating, physical vapor deposition, and carburizing technology, which can mitigate the difference in physical properties between the boride coating and the substrate material of the shovel blade, improve the surface hardness and support of the substrate material, and result in high surface hardness, core toughness, and excellent tribological properties. Compared with traditional carburizing processes, the surface hardness is increased by nearly three times, the surface treatment time is shortened by more than 90%, and the wear rate is reduced by 78-83%.

The invention discloses a heat treatment carburizing furnace waste gas purification device, and belongs to the technical field of waste gas purification, the heat treatment carburizing furnace waste gas purification device comprises a purification tower, the lower end of the purification tower is fixedly connected with a gas inlet pipe, the upper end of the purification tower is fixedly connected with an exhaust pipe, and a vibration mechanism is arranged in the purification tower; the vibration mechanism comprises a rod piece rotationally connected to the interior of the air inlet pipe, and blades are fixedly connected to the lower end of the rod wall of the rod piece. During working, waste gas impacts blades to enable a rod piece to drive a supporting block to rotate, then an inclined plate rotates in a conical block, under the action of a first vibration ball, a second vibration ball and a first spring, the conical block vibrates, molecular movement in a solution can be increased through vibration, and the solution is more uniform. The gas is introduced into the solution, contact and collision between gas molecules and reactant molecules in the solution are promoted, and meanwhile, vibration can enable gas to form smaller bubbles in the solution, so that the gas-liquid contact surface area is increased, the reaction rate is increased, and the waste gas treatment effect is improved.

The invention belongs to the technical field of metal materials, and particularly relates to steel for a long-service-life cutter and a carburizing method of the cutter, and the steel comprises the following chemical components in percentage by weight: 0.18%-0.22% of C, 0.25%-0.30% of Si, 0.50%-0.60% of Mn, less than or equal to 0.010% of P, less than or equal to 0.015% of S, 1.9%-2.0% of Cr, 1.80%-2.20% of Ni, 0.20%-0.50% of Cu and the balance of Fe and inevitable impurities. The manufacturing method has the advantages that the performance requirements of fatigue resistance and high hardness of the steel for the cutter can be effectively met through component design and a heat treatment method, and the comprehensive mechanical performance and the fatigue resistance of the manufacturing method are remarkably improved. And the surface hardness and the fatigue performance are synchronously improved by inhibiting carbide precipitation, optimizing carbon distribution and reducing retained austenite.

To provide a gas carburizing apparatus and a gas carburizing method capable of keeping carburizing nonuniformity and / or sooting of a workpiece within an acceptable range.SOLUTION: A gas carburizing apparatus of the present invention comprises a carburizing chamber configured to heat a workpiece under atmospheric pressure or a pressure higher than atmospheric pressure, and a raw gas supply device configured to supply to the carburizing chamber a mixed gas of a carrier gas and a carburizing gas containing acetylene, wherein an average concentration of acetylene contained in an atmosphere in the carburizing chamber during carburizing treatment of the workpiece is set to 0.25 vol.% or less, and the same average concentration is set to 0.10 vol.% or more.SELECTED DRAWING: Figure 2

The application provides an online detection and compensation method for local decarburization of high-strength spring steel strips, which comprises the following steps: monitoring oxygen concentration in real time by arranging an oxygen content sensor in a continuous annealing furnace and marking potential decarburization risk sections; scanning the steel strips in the risk sections by infrared thermal imaging to generate a carbon distribution map and locate decarburization zones; performing pulse laser heating on the decarburization zones and introducing a methane-argon mixed gas to realize in-situ carburization; and finally eliminating local thermal stress by high-frequency induction heating. The method realizes dynamic early warning of decarburization risk, accurate positioning of defects, local efficient carburization and stress homogenization control, and significantly improves the surface quality and fatigue performance of the steel strips.

The utility model provides a novel lifting appliance disc welding part for heat treatment of a composite drill rod. The novel lifting appliance disc welding part comprises a large lifting disc and a fan-shaped disc, the mounting groove is formed in the surface of the large hanging scaffold, and the fan-shaped disc is arranged in the mounting groove. According to the novel lifting appliance disc welding piece for heat treatment of the composite drill rod, the welding rod penetrates through the mounting hole in the surface of the fan-shaped disc, the external thread end is matched with the T38 clamping sleeve to limit the welding rod on the surface of a large lifting disc, and the composite drill rod lifting appliance disc and the composite drill rod are connected and assembled; after the matched clamping sleeve between the threads and the external thread end are stabilized, the composite drill rod is hoisted, so that the problem that the composite drill rod cannot be subjected to heat treatment in a carburizing furnace is solved, and while the problem is solved, the composite drill rod is convenient to use and good in hoisting stability, and the service life of the composite drill rod is prolonged. And the hoisting problem of the composite drill rod carburizing furnace in production is well solved.

The invention discloses a carburizing and quenching process parameter optimization method based on machine learning, and relates to the technical field of carburizing and quenching process optimizing.The method comprises the steps that a multi-source sensor is arranged, environment and process data are collected in real time, and a high-quality synchronous data set is formed through unified timestamps and process labels; by means of the preprocessed data, an environment interference model is built through deep learning or time sequence regression, and the influence of external disturbance on the depth and hardness of a carburized layer is quantified; according to a model prediction result, a self-adaptive controller adjusts the carburizing agent flow, the heating power and the heat preservation duration in real time, closed-loop regulation and control are achieved, and it is ensured that the technological conditions and the product performance are always close to preset targets; the carburized layer and the hardness of the discharged part are detected, the actual result is fed back to the model for iterative updating, and the control strategy is continuously optimized, so that the problem of unstable quality caused by environmental fluctuation in the traditional process is effectively solved, the production efficiency is remarkably improved, and the energy consumption and the test cost are reduced.

The invention relates to a method for producing liquid steel in an electric arc furnace (2) comprising successively: - defining a targeted nitrogen content wt. %Ntarg of the produced liquid steel, - introducing a metal load in the electric arc furnace (2) and - melting it for generating a steel bath (10) and a slag (12); - carburizing the steel bath (10) by adding a carbon amount equal to or greater than a minimum denitrogenation carbon amount CdeN said amount CdeN being defined as a function of the nitrogen content in excess to wt. %Ntarg at the beginning of the step (E4), - injecting a flow of oxygen to reach a nitrogen content wt. %N such that wt. %N ≤ wt. %Ntarg, - tapping the steel bath (10) to obtain the produced liquid steel.

The application relates to the field of a test method for the uniformity of a carburizing and quenching system, in particular to a method for evaluating the uniformity of a shaft furnace carburizing and quenching system, and discloses a method for evaluating the uniformity of a shaft furnace carburizing and quenching system, which comprises the following steps: selecting different steel materials according to different functional parts of the shaft furnace carburizing and quenching system; arranging detection points in the functional parts, a plurality of detection points are arranged in each layer, and the positions of the detection points in each layer are different; placing the steel materials on the detection points; processing the steel materials through the functional parts, and detecting the steel materials after the processing is completed; comparing the average value obtained by counting the detected values with a standard value, if the average value meets the standard value, the uniformity of the functional part is better, otherwise, the uniformity is poorer. The method solves the problem that the effective hardening layer depth uniformity of the entire production system of the shaft furnace carburizing and quenching system cannot be evaluated when a workpiece passes through the shaft furnace carburizing and quenching system, and achieves the effect of performing uniformity detection on the entire production system of the shaft furnace carburizing and quenching system.

To provide a technique capable of accurately determining execution timing of burnout.SOLUTION: A method for determining the timing to execute burnout in a vacuum carburizing furnace according to the present invention includes: a setting step of setting a reference range for the peak time difference, which is the time difference between the timing of a first pressure peak measured by a first pressure gauge among a plurality of pressure gauges that is equal to or greater than a predetermined threshold pressure, and the timing of a second pressure peak corresponding to the first pressure peak measured by a second pressure gauge different from the first pressure gauge, using the time-varying changes in each measured pressure in the vacuum carburizing furnace measured by the plurality of pressure gauges; an acquisition step of acquiring the time-varying changes in each measured pressure in the vacuum carburizing furnace after the setting step and acquiring the peak time difference; and a determination step of outputting that it is time to execute burnout if the peak time difference acquired in the acquisition step is outside the reference range.SELECTED DRAWING: Figure 2

The invention relates to the technical field of carburizing treatment, and discloses a cylindrical roller bearing outer ring carburizing treatment device which comprises a carburizing furnace, and the carburizing furnace comprises a furnace body; the furnace base is mounted in the furnace body; the shaking unit comprises a base table arranged on the furnace base and a movable groove formed in the furnace base; a rotating shaft is connected in the movable groove through a bearing and fixedly connected with the base table, a first gear is installed on the rotating shaft, rack plates are connected to the two sides of the first gear in a meshed mode, and reset assemblies are arranged between the rack plates and the movable groove. The shaking unit makes the base swing in a reciprocating mode through transmission of the protruding blocks and the rollers, the problems of airflow shielding, low mass transfer efficiency and uneven temperature caused by workpiece fixing in traditional static carburizing are effectively solved, all areas of the surface of the bearing outer ring are periodically exposed to the carburizing atmosphere through swing of the base, a gas flowing dead zone is thoroughly eliminated, and the carburizing effect is improved. And meanwhile, the problem of poor carburizing efficiency of an annular structure inner ring is solved.

The invention discloses a quenching process of a steel structure fastener, and belongs to the technical field of steel structure fasteners. The invention discloses a quenching process of a steel structure fastener, and aims to improve the mechanical property and wear resistance of the fastener. According to the process, steel with a specific component proportion is adopted, and the steel contains elements such as carbon, manganese, silicon, chromium, molybdenum, zirconium and tungsten, and the balance iron and inevitable impurity elements. In the machining process, the steel is subjected to ethanol solution ultrasonic cleaning, annealing and normalizing treatment firstly, then high-temperature quenching and tempering are conducted, and finally the performance is further improved through ECAP machining and carburizing treatment. According to the process, the hardness, strength and wear resistance of the steel structure fastener can be remarkably improved, and meanwhile the corrosion resistance of the steel structure fastener is improved. Especially in high-load and severe environments, the product shows excellent performance, meets the requirements of high strength and durability, and has wide industrial application prospects.

The application provides a corrosion agent and method for displaying G20CrNi4 granular bainite structure, the corrosion agent is prepared by 2%-4% nitric acid alcohol solution, hydrochloric acid and ferric chloride in the proportion of 100ml:0.3-0.7ml:0.4g-0.6g; the method for displaying granular bainite structure comprises sample preparation, corrosion agent preparation, granular bainite structure corrosion and metallographic microscope observation. The corrosion agent provided by the application is simple to prepare, the method for displaying granular bainite structure is stable and reliable, simple to operate, and can realize corrosion and clear display of granular bainite structure of carburizing bearing steel.

The present application relates to the technical field of heat treatment, and especially relates to a core-pulling type electronic wind system suitable for a carburizing furnace. The core-pulling type electronic wind system comprises an electronic wind system, a high-voltage power supply and an electronic wind blowing unit, and further comprises a carburizing furnace loading support for supporting a workpiece to be treated. The electronic wind blowing unit comprises a blowing positive electrode, a blowing negative electrode and a guide cylinder. A mesh plate is fixed to the inner wall of the guide cylinder. The air outlet direction of the guide cylinder is towards the recessed part of the workpiece to be treated. The blowing positive electrode comprises at least three core-pulling electrodes, and the at least three core-pulling electrodes are respectively slidably arranged in the holes of the mesh plate. The electronic wind system is arranged in the furnace body of the carburizing furnace. The electronic wind system forms an ion wind which is directed to flow towards the recessed part of the workpiece to be treated. The high-temperature carburizing gas is forced to enter the recessed part of the workpiece to be treated, and the waste gas is carried out at the same time. The problem of uneven thickness of the carburizing layer of different parts of the complex workpiece in the furnace body of the carburizing furnace is solved.