Development History of Heat Treatment of Needle Roller Bearing

InPrecision heat treatment, precision heat treatment has two meanings: on the one hand, it is to optimize the process parameters according to the needle roller bearing use requirements, materials, and structural dimensions of the parts, using physical metallurgical knowledge and advanced computer simulation and detection technology to achieve the required performance or maximize the potential of the material; on the other hand, it is to fully ensure the needle roller bearing stability of the optimized process, achieve very small product quality dispersion and zero heat treatment distortion.

Clean heat treatment, wastewater, waste gas, waste salt, dust, noise and electromagnetic radiation generated by heat treatment production will pollute the environment. Solving the environmental pollution problem of heat treatment and implementing clean heat treatment is one of the directions of heat treatment technology development in developed countries. In order to reduce the emission of SO2, CO, CO2, dust and coal slag, the use of coal as fuel has been basically eliminated, the use of heavy oil has become less and less, and most people use light oil instead. Natural gas is still an ideal fuel.

The waste heat utilization of the combustion furnace has reached a very high level. The optimization of the burner structure and the strict control of the air-fuel ratio ensure that NOX and CO are reduced to a very low limit under the premise of reasonable combustion. Gas carburizing, carbonitriding and vacuum heat treatment technology are used to replace salt bath treatment to reduce the pollution of waste salt and CN-containing toxic substances to water sources. Water-soluble synthetic quenching oil is used to replace part of the quenching oil, and biodegradable vegetable oil is used to replace part of the mineral oil to reduce oil pollution.

Less oxidation heat treatment, from using protective atmosphere heating to replace oxidation atmosphere heating to controlled atmosphere heating with precise control of carbon potential and nitrogen potential, the performance of parts after heat treatment is improved, heat treatment defects such as decarburization and cracks are greatly reduced, and the finishing allowance after heat treatment is reduced, which improves the utilization rate of materials and machining efficiency. Vacuum heating gas quenching, vacuum or low-pressure carburizing, nitriding, nitrocarburizing and boronizing can significantly improve quality, reduce distortion and increase life. 

Energy-saving heat treatment, scientific production and energy management are potential factors for effective energy utilization. Establishing a heat treatment plant to ensure full-load production and give full play to the equipment capacity is a scientific management choice. In terms of heat treatment energy structure, primary energy is given priority, waste heat and residual heat are fully utilized, and low-energy consumption and short-cycle processes are used instead of long-cycle and high-energy consumption processes.