| Home>Bearing knowledge> Foreign mechanical occupation bearing heat disposal method (below) |
Foreign mechanical occupation bearing heat disposal measures (below)
Source: China Bearing Network Time: 2014-06-02
| /*250*250 was created on 2017/12/25*/ var cpro_id = 'u3171089'; |
7 bearing heat treatment equipment 7.1 annealing equipment industry developed countries in the 1960s and 1970s fully implemented push-rod and roller-type isothermal spheroidizing annealing furnace; shorten the annealing cycle; save power; improve annealing quality. Follow the bearing parts The development of processing skills; the selection of fine casting and fine expansion (cold cooling) process; the processing precision of parts blanks is getting higher and higher; gradually introducing less turning technology; thus bringing the need for atmosphere annealing. The state has used annealing atmospheres to reduce the amount of machining after annealing; improve processing power; save energy and reduce costs.
7.2 Conventional martensite quenching tooling equipment The traditional heating equipment is a box furnace, salt bath furnace or pit furnace without a guarantee atmosphere; in recent decades, the martensitic quenching tooling equipment is mainly gathered in The following aspects:
(1) Active production line; the active production line selected abroad can be divided into: according to its layout (or the movement method of the workpiece in the furnace): there are muffle belt furnace and no muffle belt furnace, casting chain furnace, Production line of roller bottom furnace and drum furnace series; heating, quenching, post-cleaning (sometimes secondary deep cooling) and tempering are completed from loading, pre-cleaning, atmosphere protection (or controlled atmosphere). The degree and control precision are high; the quality of the workpiece after treatment is uniform; some production lines are equipped with on-line testing equipment for deformation or quality inspection and handling of the processed workpiece; the entire heat treatment production line can be used as a bearing production line. The use of different heat treatment production lines is suitable for the heat treatment of different types and scales of bearing parts according to its layout characteristics; for example, the mesh belt furnace is suitable for small and medium-sized bearing rings, and the roller hearth furnace is equipped with active lifting and quenching equipment; Larger bearing parts, drum furnace for rolling and small ferrules.
(2) Multi-purpose furnace multi-purpose furnace connects the controllable atmosphere heating and the quenching under the atmosphere; the process of non-oxidation quenching of the finished workpiece; the first application is suitable for the thermal treatment of small batches of various types of bearing parts.
(3) Induction heating quenching and tempering equipment Induction heating has the advantages of fast heating speed and energy saving; the workpiece after disposal has some functions that are not commonly used in heating. The volume of the equipment. Zixiao Street, 岢 咧 咧 咧 咧 咧 迪 迪 迪 ..
(4) heating under vacuum condition of vacuum furnace can reduce or prevent oxidation of workpiece; cooperative high-pressure gas quenching can control the cooling and deformation of workpiece; prevent environmental pollution caused by oil quenching; end heat treatment; other; vacuum heat After disposing; the microscopic arrangement of the workpiece is more and more even and uniform; the outer surface and the core are arranged together; the hardness is uniform; it is beneficial to the progress of the bearing fatigue life.
(5) Quenching cooling medium and quenching medium can be divided into three categories: oil-based, water-based and gas quenching medium. Oil-based quenching medium is the most commonly used quenching medium. The usual quenching oil is N32 or N15 mechanical oil; Improve its cooling function, anti-aging function, light function, high temperature function, etc. to participate in the refrigerant, scavenger, brightener, antioxidant; constitute a series of quenching oil such as fast oil, rapid glazing oil, high temperature grading isothermal oil Used for quenching of bearing parts with different scales and requirements; other low-volatility vacuum quenching oil. The disadvantage of oil-based quenching medium is that the soot in the quenching process constitutes air pollution and constitutes water pollution in the subsequent cleaning process. .
The water-based quenching medium is an aqueous solution composed of an organic polymer, an anti-corrosion agent and other increasing agents. The type and concentration of the modified organic polymer can be obtained to obtain different cooling characteristics to suit the quenching cooling requirements of different bearing parts; During the cooling process; the organic matter attached to the exterior of the part can reduce the risk of quenching and cracking of the part; and no fumes occur; the cleaning is convenient; no pollution; the development direction of the quenching medium. The lack of anti-aging function is not as good as the oil-based quenching medium; The solution is often tested; the organic solution is added periodically to ensure its cooling function.
Gas quenching is the use of inert gas as the medium (commonly used nitrogen); the compacting gas is sprayed through the specially depicted nozzle to the workpiece to finish the quenching of the workpiece. The pressure of the conditioning gas and the layout of the nozzle can control the cooling characteristics and deformation; such as Tinscher The research of [11] indicates that when the flow rate of nitrogen reaches 100m/s; its cooling characteristics are near the oil; when there is no special demand for the brightness of the appearance of the workpiece; the compact air can be used as the quenching medium; The outer layer of 3~5μm oxide layer can be removed by future grinding. Gas quenching is cleaner than water-based quenching; and the cost is lower; the key skill is the layout of the nozzle.
Quenching and cooling equipment is another major factor affecting the quenching effect of the workpiece in addition to the quenching medium. Foreign countries apply multi-parameter control to the commonly used quenching oil tank; such as oil temperature, oil cooling characteristics, oil circulation and mixing direction and speed, workpiece entry Oil method, etc.; in order to obtain the best quenching arrangement and function; together to minimize the deformation. Japan's NSK and other famous bearing companies to quench the oil for timing or online detection; according to the test results increase the required increase agent or The quenching oil is updated, on the other hand; the deformation of the workpiece after quenching is detected on-line; the workpiece with poor deformation is actively detected; the correction is performed before proceeding to the next process; the grinding allowance of the workpiece can be greatly reduced. Others; the cooling of the quenching medium in the oil tank is gradually changed from water circulation cooling to full air cooling; using air as a cooling medium saves a lot of water resources.
Multi-station active quenching press is also used in foreign quenching tooling; it can actively complete lifting, loading and unloading, fuel injection cooling, oil temperature conditioning and tension (or pressure) conditioning; microcomputer control; production beat adjustable; Can be used as a bearing active production line.
(6) Removal of equipment removal is usually an essential process after oil quenching. The cleaning equipment used in successive production lines usually ends with hot soap water soaking, water spray, hot air drying, etc.; with oil and water separation equipment. Leading removal In the equipment; secondary cooling equipment (with refrigeration equipment; temperature between 5~10 °C) is added before drying; to reduce the content of retained austenite; improve dimensional stability.
Vacuum cleaning is a cleaning device that has been carried out in these years. It uses a volatile liquid such as quenching oil to reduce the boiling point and reduce the boiling point of oil, water, water vapor and other organic liquids together to reduce the boiling point. The gas and liquid mixing pump generates fine air bubbles mixed into the cleaning liquid; the explosive force generated when the microbubbles are voted outside the workpiece damages the contact force between the stain and the workpiece; and then further improves the vacuum cleaning effect. After the front chamber is cleared; After entering the vacuum chamber; after vacuuming, the remaining oil and water are transpiration and vacuum is boring. The advantages of this type of cleaning equipment are: good cleaning effect; especially for messy parts; clearing effect is more obvious; The surface of the workpiece is bright, safe and hygienic; the cleaning liquid is clean water; the chlorine and petroleum solvents harmful to the environment are not added, and the degree of automation is high; and the cleaning heating can be used instead of low temperature tempering;
7.3 bainite austempering is equipped according to the characteristics of bearing processing; the equipment used has two main categories: active production line and cycle furnace.
(1) Active production line: Bearings with small types and large batches are suitable for active production; for example, the production of railway bearings is mostly based on active production lines. The active production line is mainly composed of atmosphere heating furnace and isothermal quenching tank; According to the measures of transporting workpieces, the equipment can be divided into three categories: rotary bottom, pusher and conveyor belt. The rotary bottom and push-plate isothermal quenching equipment developed by Ai Xia Lin Company puts the bottom or pusher tissue in isothermal condition. In the salt bath; the workpiece enters and exits according to the certain beat; recalls the order of control; the action is controlled by the PLC program; the equipment is highly active; the investment is large, and the conveyor belt type austempering active line developed by Shafei Company and the current The mesh belt type atmosphere-preserving active line layout principle is similar; only the quenching medium used is salt.
(2) Periodic austempering equipment: rolling mill bearings because of various types, batches, ⌒驮岢 ⌒驮岢 Ъ å—–æŽ å—–æŽ å—–æŽ + + + + quenching cooling tank + isothermal tank + clearing tank; also have box furnace + multiple isothermal tank The equipment has less capital contribution; the applicability is strong; but the labor intensity is high; the safety is poor. Epson combines the multi-purpose furnace and the bainite quenching isothermal to prevent oxidation between the heating equipment and the austempering, and isotherm The air furnace is selected and equipped with a residual salt recovery system to prevent environmental pollution of residual salt. In addition, the characteristics of the multi-purpose furnace can be used for the disposal of small batches of various types of bearing parts; the scale constraint of the usual active isothermal equipment is overcome. Currently; in the implementation of bainite austempering; the equipment has great value.
7.4 Guarantee atmosphere and control followed by the improvement of the surface quality requirements after quenching the workpiece; the (controllable) atmosphere heating is more and more popular; the heat treatment including annealing is controlled by a guaranteed (or controllable) atmosphere. 20th century In the 1970s; the first choice was the endothermic atmosphere. The endothermic atmosphere was a mixture of the material gas and the air. Under the effect of the catalyst, some reactions constituted a kind of 18~23% CO, 37~42% H2, and the balance N2. Atmosphere. In the 1980s; the world's power crisis brought great impact to the world economy; the nitrogen-based atmosphere came into being; the composition of the nitrogen-methanol atmosphere and the endothermic atmosphere; the nitrogen-based atmosphere represented by nitrogen-methanol was widely promoted. In the 1990s; the gas production method of directing air and hydrocarbons directly into the furnace above 800 °C; that is, the direct atmosphere. It was discovered through research; this atmosphere rich in high CH4 composition; despite its gas reverberation The degree of balance similar to the endothermic atmosphere is not achieved; but the carbon transport can still be controlled by the content of CO and H2 in the atmosphere; the carbon potential control can be completed by contacting the CO2 analyzer with an oxygen probe. The main strength of the atmosphere is a lot of festivals. According to statistics, this atmosphere is still a continuous atmosphere furnace in the periodic atmosphere furnace; its material gas consumption costs about 70%. Today; more than 300 sets of atmosphere furnaces around the world use this atmosphere 4. Carburizing, carbonitriding, atmosphere quenching and other heat treatment.
The practical application in recent years indicates that the life expectancy of the oxygen probe is variable; the gradual drift of the oxygen probe signal is caused by the typical shortcomings of the fixed electrolyte. Because this drift is mainly affected by the operating conditions of the furnace; The beginning and large drift are not foreseen; therefore, the difference between the carbon potential measured by the oxygen probe and the practical value is not foreseen. Therefore, everyone regularly verifies the measurement accuracy; for example; once a week; with steel foil Fixed carbon film to detect whether the oxygen probe signal can be distorted; this is really a troublesome operation; it is not conducive to the complete activation of the furnace; sometimes it will affect the normal production. In view of the above reasons; Ipsen developed a two-layer measurement system.
In the meantime, a standard oxygen probe is used for normal control of the carbon potential; another independent measurement system is used to detect the operation of the oxygen probe; that is, the two systems separate the carbon potential of the measured atmosphere; when the result shows a large error; Will alarm. This second measurement system operating component can be a CO2 infrared analyzer; it can also be a miniature oxygen probe (λ-probe); so far; there are many atmosphere furnace equipment for this two-layer measurement system.
Recommend to friends comments close window
| Bearing related knowledge |
| Commonly used several types of rolling bearing disassembly method: the cone crusher bearing repair method long-term import SKF angle touch ball bearing process requirements in advance to prevent the import of bearings primary damage mode retaining ring type roller needle bearing |
This article links to http://
Please indicate the bearing network http://
Previous:After the NSK bearing equipment work view analysis Next: SKF bearing rolling bearings are divided into several public service levels
Basin Faucet,Face Basin Faucet,Basin Sink Faucet,Hot And Cold Basin Taps
AIHUI Sanitary Ware , https://www.fsaihuisanitary.com