Bearing processing and heat treatment process and technology application effect

Heat treatment development ( 1) Clean heat treatment formed by heat treatment production wastewater, waste gas, FeiYan, dust, noise and electromagnetic radiation can cause pollution to the environment. Solve the problem of heat treatment of environmental pollution, implementation of clean heat treatment ( Or green heat treatment) Is one of the developing direction of the heat treatment technology in the developed countries. For reducing SO2, CO, CO2 emissions, dust and coal cinder, have put an end to coal as fuel, fewer and fewer in the use of heavy oil, diesel oil in the majority of natural gas is still the most ideal fuel. Combustion furnace waste heat utilization has reached a very high degree, and empty - burner structure optimization Fuel ratio under the premise of strict control to ensure the reasonable combustion, NOX and CO to reduce to a minimum; Using gas carburizing, carbonitriding and vacuum heat treatment technology instead of salt bath treatment to reduce FeiYan and CN - Have poison to the water pollution; With water soluble synthetic quenching oil instead of part of the quenching oil, using biodegradable vegetable oil instead of part of the mineral oil to reduce the oil pollution. ( 2) Precision heat treatment of heat treatment has the meaning of two aspects: on the one hand, is based on the use requirements of the parts, material, structure, size and the use of physical metallurgy knowledge and advanced computer simulation and testing technology, optimization of process parameters, to achieve the required performance or maximize the potential of materials; On the other hand is fully guarantee the stability of the optimization process to achieve product quality dispersion is small ( Or zero) And heat treatment distortion is zero. ( 3) Energy saving heat treatment of the science of energy production and energy management is the effective use of the most potential factors, establish a professional heat treatment plant to ensure the full production, give full play to the equipment capacity is the choice of scientific management. In terms of heat treatment energy structure, energy choice time; Make full use of waste heat, waste heat; With low energy consumption, short cycle of process instead of the long cycle, energy consumption, etc. ( 4) No less oxidation heat treatment by using heat protective atmosphere heating instead of oxidizing atmosphere to accurate control of carbon potential, nitrogen potential controlled atmosphere heating, parts performance was improved after heat treatment, heat treatment defects such as decarburization and cracks reduce greatly, finish machining allowance reduced after heat treatment, improve the utilization rate of material and machining efficiency. Add heat quenching vacuum, vacuum and low pressure carburizing, nitriding, nitrogen and carbon altogether permeability and boriding can obviously improve quality, reduce the distortion and improve life. Application effect of heat treatment technology, 1) To expand the application range of GCr15 steel, M generally GCr15 steel quenching ring effective wall thickness under 12 mm, but the BL quenching by nitrate cooling ability is strong, if use the measures, such as stirring, string move, add water ring effective wall thickness can be expanded to about 28 mm. ( 2) Hardness is stable, good uniformity of the BL change is a slow process, generally GCr15 steel 4 h, GCr18Mo steel need 5 h, ring in long isothermal nitrate, on the surface of the core organization transformation almost simultaneously, so the hardness of stability, uniformity, good general GCr15 steel BL after quenching hardness in 59 ~ 61 HRC, uniformity of 1 or less HRC, unlike when quenching ring wall thickness slightly bigger appears low hardness, soft point, poor uniformity. ( 3) Reduce quenching and grinding cracks in rail, rolling mill bearing production, because the ring size, weight, oil quenching M the organization brittleness is big, to obtain high hardness after quenching is often strong cooling measures, as a result, quenching cracks; And BL quenching, because is much better than M BL organization toughness, surface formed up to at the same time 400 - - 500 mpa compressive stress, greatly reducing the quenching crack tendency; When grinding surface compressive stress to offset some of the stress, makes the overall stress level drops, greatly reducing the grinding crack. ( 4) Improve the service life of bearing to bear large impact load of railroad, rolling mill bearings, etc. , after M quenching when using main failure forms is: inner sleeve cracking when assembling, use in the process of impact outer ring, inner ring fracture, falling guard and isothermal quenching bearing with good impact toughness, surface compressive stress, whatever the assembly inner sleeve craze, or using Chinese and foreign set of guard metal shed and inner sleeve fracture tendency is greatly reduced, and can reduce the edge stress concentration of roller. Therefore, after isothermal quenching than M after quenching the average life expectancy and improve reliability.