710 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 provides a partitioned strengthening and toughening treatment method for an additive remanufacturing hot forging die, which comprises the following steps of: firstly, deeply cleaning a cavity of a failed forging die to remove impurities, residues and the like in the cavity, and creating a good basic condition for subsequent remanufacturing treatment; secondly, the repairing area of the forging die is subjected to remanufacturing treatment, so that the basic toughness requirement of the additive remanufacturing hot forging die is met, and cracking is prevented; afterwards, selective surface nitriding or carburizing strengthening treatment is conducted on the strengthening area of the additive remanufacturing hot forging die, so that the strength and hardness of the strengthening area are improved, the abrasion resistance is guaranteed, the strength and toughness partition of the surface of a cavity of the additive remanufacturing hot forging die is achieved, and then the comprehensive performance of the strengthened hot forging die is comprehensively improved; and finally, the service life of the reinforced hot forging die is prolonged.

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

This method for producing a steel member includes: a carburizing step of causing carbon to infiltrate into a steel member in an austenitized state by heating the steel member to a temperature equal to or higher than an austenitic transformation completion temperature, at a carbon concentration at which the steel member and the carbon have a hypoeutectoid composition, and removing cold from the steel member in which the carbon has been caused to infiltrate; and a quenching step of, after the carburizing step, heating the steel member again to a temperature equal to or higher than the austenitic transformation completion temperature, and rapidly cooling the steel member that has been heated.

The invention relates to the field of metal processing, and discloses a processing method of high-strength medium alloy carburizing steel, which comprises the following steps of: assembling parts and welding to form a product: aligning all the parts forming the product through corresponding grooves in a contact manner, and assembling all the parts to be welded to form a product prototype; carrying out integral preheating treatment on the to-be-welded parts which are integrally placed and assembled before welding, wherein the preheating temperature is 200-250 DEG C; after the temperature of all the to-be-welded parts is reached, welding the groove contact edges of the two to-be-welded parts which are placed and contacted one by one, so that a welding seam with a certain width is formed between the base materials of the two parts; all to-be-welded parts of the whole product are continuously heated in the welding process, and it is guaranteed that the temperature of the to-be-welded parts is always kept at 200-250 DEG C in the welding process; dehydrogenating the whole product; performing stress relief annealing on the whole product; and integrally tempering the product. According to the scheme, the overall performance of a welding product is effectively improved, and the performance homogenization of welding seams and part base metal is effectively improved.

The embodiment of the invention relates to a machining method of small-deformation gear steel and a gear piece, and belongs to the technical field of gear steel. The machining method comprises the following steps: S1, carrying out microalloying treatment on the gear steel by adopting Ti and / or Nb; s2, the gear steel subjected to microalloying treatment is rolled, and a gear steel bar is obtained; s3, the gear steel bar is sequentially subjected to blank forging, heat treatment after forging and machining, and a to-be-carburized gear is obtained; s4, the gear to be carburized is subjected to carburizing treatment and diffusion treatment, and a gear piece is obtained; s5, the gear part is subjected to gas quenching treatment, and the gear part is cooled to the room temperature in stages; and S6, the gear piece subjected to gas quenching treatment is subjected to tempering treatment. According to the invention, through the microalloying treatment of the gear steel and the staged gas quenching treatment of the gear piece, the quenching deformation of the gear piece is controlled, and the deformation after quenching is greatly reduced, so that the gear piece with good dimensional precision control is obtained.

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 discloses a method for regulating and controlling carburizing efficiency of gear steel by using high-density grain boundaries, which comprises the following steps of: S1, pretreating the gear steel to change the internal microstructure state of the gear steel, and generating the high-density grain boundaries on the surface layer and the subsurface layer; s2, the pretreated gear steel is subjected to carburizing treatment; and S3, the gear steel subjected to carburizing treatment is subjected to conventional heat treatment. A high-density large-angle grain boundary is introduced to the surface of the gear steel, carbon atoms can be attached more easily, the content of the carbon atoms on the surface layer of the gear steel is increased, and the surface layer hardness of the gear steel is improved; meanwhile, the depth of a carburizing layer of the gear steel can be increased, large-angle grain boundaries are more beneficial to diffusion of carbon atoms, along with carburizing, the surface layer of the pretreated gear steel contains a large number of large-angle grain boundaries, the diffusion efficiency of the carbon atoms in the gear steel is higher than that of unpretreated gear steel, and therefore the depth of the carburizing layer is increased, and the carburizing efficiency is improved; according to the invention, the time cost and the energy consumption are greatly optimized.

The invention relates to the technical field of metal welding, and discloses a welding process of high-strength medium alloy carburizing steel, which comprises the following steps: preheating the whole weldment to 200-250 DEG C before welding; the overall temperature of a weldment is kept at 200-250 DEG C in the welding process; and after welding is completed, a weldment is integrally heated to 250-300 DEG C, and heat preservation is conducted for preset time. According to the scheme, a new preheating technology in the welding technology is provided for the high-strength medium alloy carburizing steel, overall preheating is adopted before welding, during welding and after welding instead of local preheating, the temperature ranges before welding and during welding are kept consistent, the temperature range after welding is slightly higher than the temperature ranges of the first two stages, it is advantageously kept that the temperature of a mother part in the whole welding stage is stable and uniform, and the welding quality is improved. The temperature gradient in the whole welding process is reduced to the minimum, and through appropriate process steps and welding parameters, it is guaranteed that weld joints do not have welding defects, and meanwhile the mechanical property requirements of products are met.

According to the method for controlling the grain size of the low-carbon bearing steel through cooperation of nitrogen circulation and niobium, the smelted raw material ferroniobium is expensive, by means of nitrogen circulation, the grain size is optimized, meanwhile, the adding amount of ferroniobium is reduced, and low-cost smelting is achieved; the niobium element can be combined with carbon and nitrogen to form niobium (carbon and nitrogen) particles, and the undissolved niobium (carbon and nitrogen) particles become second-phase particle pinning grain boundaries to improve the resistance of grain growth, so that the migration of the grain boundaries is inhibited, the grains are refined, the hardness after quenching is improved, and the wear resistance is also improved. The method disclosed by the invention has the beneficial effects that by adopting the method disclosed by the invention, the cost is reduced, an obvious local grain coarse area does not appear on a 20Cr sample along with the prolonging of carburizing time, the grain size is always relatively stable at 7-8 levels, the average quenching hardness is 43HB, and the wear resistance is greatly improved.

The invention provides a method for improving wear resistance of an ejector pin hole through carburizing, nitriding and laser modification composite strengthening. The method comprises the following steps: ultrasonically cleaning the inner surface of the ejector pin hole; the ejector pin hole component is subjected to vacuum carburizing treatment, and a transition layer containing a mixed structure of twin-crystal martensite and a small amount of austenite is obtained; carrying out ion nitriding treatment on the centre hole component; and carrying out laser oblique impact strengthening on the ejector pin hole. According to the method for improving the wear resistance of the ejector pin hole through carburizing, nitriding and laser modification composite strengthening, the wear resistance of the ejector pin hole can be effectively improved.

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 manufacturing method of the integrated rigid centralizer comprises the steps that S1, steel is subjected to hot rolling to obtain a seamless steel pipe; s2, the seamless steel pipe locally protrudes outwards in the radial direction to deform through internal high-pressure forming, a plurality of spiral centralizing edges are formed on the surface of the seamless steel pipe, and the multiple centralizing edges are arranged on the outer surface of the seamless steel pipe in a surrounding mode; s3, carburizing, quenching and tempering the seamless steel tube with the centralizing edges obtained in the step S2; according to the integrated rigid centralizer, centralizing edges are spiral, the multiple centralizing edges are attached to the outer surface of a cylinder in a surrounding mode and are integrally connected with the cylinder, and smooth arc-shaped transition sections are integrally connected between the cylinder and the centralizing edges. According to the manufacturing method, the integral rigid centralizer without a welding seam or other connecting structures can be manufactured in an internal high-pressure forming mode, and the integral rigid centralizer can smoothly pass through a narrowed part and a bent part of an oil well; the centralizer has the advantages of being high in rigidity, uniform in thickness, high in precision, free of excessive stress concentration, excellent in structural performance, not prone to damage, long in service life and the like.

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

The invention 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 belongs to the technical field of heat treatment, and particularly relates to a wind power planet wheel carburizing and quenching process, which comprises the following steps: carrying out temperature equalization treatment twice before carburizing, carrying out strong carburizing once and diffusion treatment twice in a carburizing stage, quickly cooling to a high return temperature, carrying out temperature equalization, entering a slow cooling pit, cooling to a certain temperature, discharging from a furnace, and carrying out air cooling. Preheating in a tempering furnace before quenching, entering the furnace at high temperature and high carbon potential, entering a salt bath for quenching after austenitizing, controlling the water content of the salt bath, and improving the quenching intensity. According to the method, it can be guaranteed that the temperature of a workpiece rises at a slow speed before carburizing, the thermal stress influence caused by too large temperature difference is avoided, carbon deposition is reduced through two-time diffusion, and it is guaranteed that the surface metallographic structure meets the technical requirement; preheating is conducted before quenching, high-temperature and high-carbon-potential furnace feeding is conducted, it is guaranteed that a workpiece is rapidly heated in a nucleation temperature interval, and a good martensite structure is obtained; by controlling the water content of the salt bath, the quenching cooling speed can be increased, the formation of a bainite structure is reduced, and meanwhile, the requirement of the wind power planet wheel for the inner hole hardness is met.

The invention provides a carburized ethylene cracking furnace tube residual life prediction method based on small punched hole outer surface sampling. The method comprises the following steps: sampling the outer surface of an in-service ethylene cracking furnace tube by using a small punched hole sampling machine; performing a small-punching high-temperature creep test on the sample; carrying out equivalent stress conversion based on a creep test result; establishing an outer surface residual life prediction equation; calculating furnace tube stress and substituting the furnace tube stress into the prediction equation to obtain outer surface residual life; performing carburization-creep finite element simulation on the furnace tube of the ethylene cracking furnace; obtaining a furnace tube damage distribution condition of a finite element test result; and the overall residual life prediction is completed through the outer surface residual life and the damage distribution relationship. According to the method, furnace tube interruption or production halt is avoided, time and cost are saved, residual life prediction is carried out based on actual sampling and finite element data analysis, and the method has high reliability and accuracy and is used for early warning and maintenance decision making in advance, prolonging the service life of equipment and avoiding resource waste and accidents.

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 is a bearing track member that comprises a shaft section that comprises a first portion and a second portion. A first steel material is used as a material of the first portion, a second steel material is used as a material of the second portion, and the alloy composition of the first steel material differs from the alloy composition of the second steel material. The first portion has a bearing portion that has a track, and the second portion has a power transmission portion that has teeth. The first portion has a first surface hardened layer, disposed along an outer peripheral surface of the first portion, and a first inner section, and the average hardness of the first surface hardened layer is greater than the average hardness of the first inner section. The second portion has a second surface hardened layer, disposed along an outer peripheral surface of the second portion, and a second inner section, and the average hardness of the second surface hardened layer is greater than the average hardness of the second inner section. The first surface hardened layer and the second surface hardened layer are each a carburized layer or a carbonitrited layer, and the first surface hardened layer and the second surface hardened layer are connected. The combination of the first steel material and the second steel material is at least one of the following first through fourth combinations. The first combination is a combination in which the first steel material and the second steel material each include at least one of manganese, nickel, chromium, and molybdenum, the total manganese, nickel, chromium, and molybdenum content of the first steel material being greater than 1.5 times the total manganese, nickel, chromium, and molybdenum content of the second steel material. The second combination is a combination in which the first steel material and the second steel material each include silicon, the silicon content of the first steel material being less than the silicon content of the second steel material. The third combination is a combination in which the first steel material includes either no chromium or no more than 1.6% by mass of chromium and includes either no niobium or no more than 0.01% by mass of niobium, and the second steel material includes at least 1.0% by mass and no more than 2.5% by mass of chromium and includes at least 0.02% by mass and no more than 0.10% by mass of niobium. The fourth combination is a combination in which the first steel material includes at least 0.001% by mass and no more than 0.050% by mass of nitrogen, includes either no boron or no more than 0.001% by mass of boron, and includes either no titanium or 0.003% by mass of titanium, and the second steel material includes at least 0.001% by mass and no more than 0.050% by mass of nitrogen, includes at least 0.001% by mass and no more than 0.005% by mass of boron, and includes at least 0.01% by mass and no more than 0.08% by mass of titanium.

The invention relates to a bearing detection technology, in particular to a high-temperature carburizing steel bearing ring specific surface carburizing local pickling process which comprises the following steps: S1, preparing a pickling solution according to the following components in percentage by mass: 2-5% of nitric acid, 3-5% of hydrochloric acid, 3-5% of ferric trichloride and 85-90% of water; s2, degreasing and cleaning; s3, protection before pickling; coating a protective layer outside the local surface of the specific surface carburized layer of the bearing ring; s4, the local surface is subjected to acid pickling; the pickling time is 90-150 seconds; s5, cleaning after acid pickling; a protective layer is removed, and then cleaning, brightening, neutralizing and rust prevention are conducted in sequence; and S6, inspection. According to the invention, whether a carburized layer exists in a certain area of the bearing ring can be rapidly and accurately detected, the pickling corrosion is uniform, over-corrosion is avoided, and whether a carburized layer exists in a certain area of the bearing ring and whether the carburized layer is uniform can be rapidly and accurately detected.

The utility model relates to the technical field of machinery manufacturing, in particular to a bulldozer crawler-type carburizing sleeve quenching tool which comprises a bottom plate, a heating mechanism, a cooling box and a spraying mechanism, the heating mechanism is arranged at the upper end of the bottom plate, the cooling box is arranged at the upper end of the bottom plate, the spraying mechanism is arranged at the upper end of the cooling box, and the spraying mechanism is arranged at the lower end of the cooling box. A filter box is mounted on one side of the cooling box in an embedded manner, and an air outlet filter screen is arranged on the other side of the cooling box; the heating mechanism is arranged, in the using process, a first motor and a heater are started, the first motor drives the shell to rotate, the heater heats raw materials, the shell rotates to enable the raw materials to be evenly heated, and the situation that the production qualification rate is reduced due to uneven heating is avoided; and after raw material processing is completed, raw materials are cooled through the spraying mechanism, meanwhile, a second motor is started in the cooling process to drive fan blades to rotate, water vapor generated in the water spraying cooling process is discharged through an air outlet filter screen, and the production efficiency is improved.