422 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 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 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 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.

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 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 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.

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 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.

The invention relates to the technical field of metal material surface chemical heat treatment, in particular to W-containing ultrahigh-strength steel, a preparation method thereof and a surface carbon-nitrogen composite strengthening process. The preparation method comprises the following steps of smelting preparation of steel, forging cogging forming, annealing heat treatment after forging of a bar, carburization, subzero treatment and surface pressurization nitriding. The ultrahigh strength steel comprises the following chemical components: 0.27-0.34 wt.% of C; 0.4 to 1.4 wt.% of Cr; 9 to 10 wt.% of Ni; 6 to 8 wt.% of Co; 1.5 to 2.5 wt.% of Mo; 1.1 to 1.6 wt.% of W; and the balance of Fe and impurity elements. The highest hardness of the carbonitriding layer of the W-containing ultrahigh-strength steel is not lower than 900 HV, the tensile strength of the steel is not lower than 2000 MPa, the yield strength is not lower than 1700 MPa, the impact absorption capacity is not lower than 60 J, and the service condition requirements of gears for aero-engines are met.

The utility model relates to the technical field of dismounting tool, disclose a nut breaker, the utility model includes a breaker main part and screw rod, the through channel is equipped in the breaker main part, the right -hand member of breaker main part is equipped with annular head and is fixed with fixed breaker blade in annular head inner wall, fixed breaker blade is made through high carbon steel, and carburizing quenching treatment, the Rockwell hardness of fixed breaker blade is higher than the Rockwell hardness of nut. The utility model will annular head suit in the outside of nut, make fixed breaker blade resist in nut lateral wall, then through spanner rotation screw rod, and then will movable breaker head forward push, make movable breaker blade and fixed breaker blade form bidirectional shearing, carry out powerful removal to nut, and the heat will not be produced due to the high speed friction with nut in the dismounting process.

This invention discloses a dual-frequency composite induction strengthening process for medium carbon steel, gradient hardened layer parts, and a production system. The process includes: selecting SAE 1045 medium carbon steel and performing quenching and tempering pretreatment; precision machining to form outer circular channels and inner ball channels; performing dual-frequency composite induction hardening on the outer circular channels and inner ball channels respectively, i.e., preheating to 680-750℃ with medium-frequency current, then rapidly heating to 880-920℃ with high-frequency current followed by spray cooling, and using thermal balance control to form a gentle transition zone with a width of 2-5mm between the two hardened zones, where the hardness gradient along the axial line connecting the two hardened zones does not exceed ΔHRC10 / mm; finally, low-temperature tempering. This invention also discloses wear-resistant parts with a dual-layer composite hardened layer structure and a gradient transition zone prepared using this process, as well as an online composite strengthening production system. This invention replaces low-carbon alloy steel with medium-carbon steel and replaces overall carburizing with local dual-frequency induction hardening, which can reduce raw material costs and energy consumption, reduce deformation, and obtain a hardened layer that meets the depth requirements, thus realizing online continuous production of heat treatment and machining.

The invention belongs to the field of ferrous metallurgy, and particularly relates to high-temperature-resistant carburizing aluminum-free 20CrMnTi gear steel and a preparation method thereof, and the gear steel comprises the following chemical components in percentage by weight: 0.18%-0.23% of C, 0.17%-0.23% of Si, 0.95%-1.15% of Mn, 1%-1.35% of Cr, 0.04%-0.06% of Ti, less than or equal to 0.0008% of B, less than or equal to 0.020% of P, less than or equal to 0.015% of S, less than or equal to 0.010% of Alt, less than or equal to 0.005% of N and the balance of Fe and other inevitable impurities. The aluminum-free 20CrMnTi gear steel has the advantages that the three-in-one design thought of component design, precipitated phase regulation and control and process optimization is adopted, the aluminum-free 20CrMnTi gear steel is obtained, and the aluminum-free 20CrMnTi gear steel is refined in grain under high-temperature carburization, high in hardenability, low in cost and suitable for high-end transmission parts.

The application discloses a composite modification process of a high-toughness wear-resistant cutter ring for a shield tunneling machine, and comprises the following steps: step one, a medium-carbon alloy steel material is used as a cutter ring base body, and a blank is prepared by using a hot forging process; step two, the blank obtained in the step one is subjected to carburizing quenching treatment, and then is subjected to oil cooling; step three, the cutter ring after the oil cooling in the step two is subjected to high-temperature tempering treatment, so that unstable martensite after quenching is completely converted into tempered martensite; step four, the cutter ring after the high-temperature tempering in the step three is subjected to surface induction quenching; step five, the cutter ring after the induction quenching in the step four is subjected to low-temperature tempering treatment; and step six, the cutter ring after the low-temperature tempering in the step five is subjected to surface layer ultrasonic impact modification, so as to obtain a composite modified cutter ring. The application uses heat treatment processes such as carburizing and nitriding and ultrasonic impact modification, and constructs a gradient structure cutter ring, so that the cutter ring has high wear resistance, buffer resistance and impact toughness.

The present application belongs to the field of metal materials, and particularly relates to a high-temperature carburizing process method of gear steel quenched by different media. The present application develops the carburizing process of gear alloy carburizing steel by finite element simulation mode, and proposes a double-medium quenching process to improve the phase organization of the core of the sample, reduce the martensite content of the core, increase the bainite content, thereby reduce the hardness of the core, and further improve the toughness of the core of the sample, on the basis of ensuring the control of production cost, without increasing the process flow and improving the use performance. The carburized surface is still martensite organization, and the high hardness of the surface layer is maintained.

The invention discloses a transmission system gear type part and surface quality improving process method, which comprises the following steps: after carburizing, quenching and shot blasting of a part, carrying out a liquid sand blasting process to remove part burrs and redundant substances; cleaning dust and greasy dirt on the surface of the part by using a saturated steam cleaning machine after the part is heated and gear grinding is finished; strengthening shot blasting treatment is conducted on the part; after the reinforced shot blasting is completed, a cleaning procedure is carried out, and shot blasting ash generated after the reinforced shot blasting of the part is removed; after cleaning is completed, the anti-rust oil coating procedure is conducted, and an oil coating machine is used for automatically coating the parts with anti-rust oil; after anti-rust oil is coated, packaging is conducted, and the parts are sealed and packaged one by one through oiled paper and then put in storage; wherein the interval time between the working procedures of gear grinding, cleaning, reinforced shot blasting, cleaning, anti-rust oil coating and packaging does not exceed 7 days. According to the transmission system gear type part and the surface quality improving process, the surface appearance quality of the gear type part can be effectively improved, and the use performance of a product is improved.

The present invention belongs to the field of metal surface treatment and relates to a composite boronizing agent and a solid boronizing method for oil pipes. The composite boronizing agent comprises a boronizing agent and graphite. Calculated on the basis of mass percentage, the graphite is 10-14% of the mass of the boronizing agent. The boronizing agent comprises the following raw materials in mass percentages: boron source: 10-15%, catalyst: 12-20%, activator: 8-10%, dispersant: 4-6%, filler: 50-55%, and flow aid: 8-12%, and the dispersant is triethanolamine borate. In the composite boronizing agent of the present invention, the triethanolamine borate can remove impurities from an inner surface of an oil pipe, improve the boronizing effect and boronized layer quality, and form a protective film to prevent carburization, promote boronizing, and enhance boronized layer bonding strength. In addition, through the combined action of triethanolamine borate and graphite, the boronizing agent can be prevented from agglomerating or adhering to the inner surface of the oil pipe after boronizing treatment, and the uniformity of boronizing can further be improved.

The invention belongs to the technical field of chains, and particularly relates to a precise chain roller with a smooth surface and abrasion resistance and a preparation method thereof. The invention provides a steel roller which is provided with a DLC final working surface on an excircle mirror surface, an excircle has no texture, and only an inner hole is provided with a micron-sized spiral microgroove. The process is implemented according to the sequence of carburizing / quenching / tempering-shot blasting-fine grinding-superfinishing-vacuum PVD, a diamond-like carbon composite coating is formed on an outer circle, and oil storage and capillary pumping are carried out through control of an outer edge fillet, residual compressive stress and DLC adhesive force and an inner hole microgroove, so that work division of antifriction bearing and oil supply functions is realized. A chain provided with the anti-abrasion precision roller with the smooth surface gives consideration to low friction, low noise and stripping resistance under the boundary lubrication and impact-rolling composite working conditions.

The utility model discloses a waste gas treatment device of a carburizing furnace, which belongs to the technical field of heat treatment equipment and comprises a box body, the air inlet assembly is located below the box body, and the air inlet assembly is located on the right side of the air supply assembly; the air supply assembly is located on the lower left portion of the box body and located on the inclined left portion of the air storage assembly; the air storage assembly is located in front of the box body and located on the right side of the air blowing assembly; the air blowing assembly is located on the inclined right side of the box body, and the air blowing assembly is located behind the air supply assembly. When waste gas enters a gas inlet box, the waste gas is fed into a combustion pipe through a gas inlet pipe on the gas inlet box, then oxygen is fed into a gas supply pipe through an oxygen tank in a gas supply box, the oxygen is sprayed into the combustion pipe through a gas supply spray head on the gas supply pipe, and then the waste gas is ignited through ignition of an electronic igniter; the threat of the waste gas to the body health of workers is avoided, and the occurrence of dangers is reduced.