Bearing heat treatment method introduction

The development of thermal treatment
(1) Clean thermal treatment
The wastewater, waste gas, waste salt, dust, noise and electromagnetic radiation formed by thermal treatment of heat treatment will cause pollution to the environment. To solve the problem of environmental pollution of thermal treatment, the implementation of clean thermal treatment (or green environmental protection heat treatment) is one of the directions for the development of thermal treatment technology in developed countries. In order to reduce the discharge of SO2, CO, CO2, dust and slag, the use of coal for fuel has been basically eliminated, and the amount of heavy oil has become less and less. Most of the light oil is used, and natural gas is still the most ideal fuel.
The use of waste heat of the combustion furnace has reached a high degree, the optimization of the burner structure and the strict control of the empty-burning ratio ensure reasonable combustion, reducing NOX and COs Nitrogen penetration and vacuum heat treatment technology replace salt bath treatment to reduce the pollution of waste salt and CN-toxic substances to water sources; use water-soluble synthetic quenching oil instead of some quenching oil, and use biodegradable vegetable oil instead of some mineral oil to reduce oil pollution Essence
(2) Precision thermal treatment
Precision thermal treatment has two meanings: on the one hand, according to the requirements of parts, materials, and structural sizes, use physical metallurgy knowledge and advanced computer simulation and detection technology to optimize process parameters. To achieve the required performance or maximize the potential of materials; on the other hand, fully ensure the stability of the optimized process, and achieve the product quality dispersal (or zero) and thermal treatment distortion to zero.
(3) Energy -saving thermal treatment
Scientific production and energy management is the most potential factor for the effective utilization of energy. Establishing a professional thermal treatment plant to ensure full load production and give full play to the ability of equipment capabilities is the choice of scientific management. In terms of heat treatment energy structure, the first energy sources are given priority; the use of waste heat and residual heat; the use of low energy consumption and short cycle to replace the long cycle and high energy consumption process.
(4) Little oxidant thermal treatment
Heating from the atmosphere of the protection atmosphere with the use of a protective atmosphere to the controlling atmosphere of accurate control of carbon and nitrogen potential. Cracks such as cracks have been greatly reduced, and the retention of precision processing after heat treatment has been reduced, which improves the utilization rate and machine processing efficiency of materials. Vacuum heating gas quenching, vacuum or low -pressure carburizing, nitrogen seepage, nitrogen carbon coexistence, and boron pouring can significantly improve quality, reduce distortion, and improve life.

The application effect of thermal treatment technology
(1) Expanded the application range of GCR15 steel
Generally, the effective wall thickness of the sleeve is below 12mm during GCR15 steel M Strong, if measures such as stirring, skewers, and water are used, the effective wall thickness can be expanded to about 28 mm.
(2) Stable hardness and good uniformity
Because the BL transformation is a slow process, generally GCR15 steel needs 4h, GCR18MO steel needs 5h, the sleeve is in the middle of nitric salt, and the transformation of the surface of the surface of the surface is almost almost changed. sameIt is carried out in time, so the hardness is stable and uniform. Generally, the hardness of the GCR15 steel BL is 59 ~ 61HRC, uniformity \\u0026 le; 1 HRC. Poor sexual problems.
(3) Reduce quenching and grinding cracks
In the production of railway and rolling bearing, due to large size and heavy weight, the M tissue is crispy during oil quenching. Cooling measures, resulting in quenching micro-cracks; while BL quenching, because the BL tissue is much better than the M tissue of the M tissue, at the same time, the surface formation of -400 ~ -500MPa has a pressure stress, which greatly reduces the tendency of quenching cracks; The surface compression stress offset some grinding stress, reduce the overall stress level, and greatly reduce grinding cracks.
(4) Increased service life of the bearing
For railways, rolling mill bearing, etc. that to withstand large impact loads, the main form of failure after use is quenching. Blinds and inner circles are cracking, and the temperature quenching bearing is good due to good impact toughness and surface compression stress. Regardless of the internal collapse during assembly, or the tendency of the inner case of the inner cover, the inner case is greatly reduced, and the inner case is greatly reduced. Can reduce the edge stress concentration of the roller. Therefore, the average life and reliability of the average quenching after the temperature of the temperature increase the average life and reliability.