Improve after quenching roller bearing surface quality requirements
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Time:2016.07.04 News Sources:Shandong Xinkaite bearing Co.,Ltd. Views:
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With the increase of roller bearings after quenching the workpiece surface quality requirements, protection (controlled) atmosphere heating is becoming increasingly popular, including heat treatment including annealing are used to protect (or controlled) atmosphere heated.
In the 1970s, mainly in endothermic atmosphere. Endothermic atmosphere is a mixture of gas and air feed gas under the action of a catalyst to form a part of the reaction containing (CO) 18% ~ 23%, (H2) 37% ~ 42%, the balance N2 protective atmosphere, this Chinas imports of heat-treated in an atmosphere of art as well as bearing applications. Propane in a nitrogen atmosphere of heat treatment and quenching line bearings in the field of the most widely used, methanol component nitrogen atmosphere with endothermic atmosphere similar to nitrogen - methanol as the representative of a nitrogen-based atmosphere in the mesh belt furnace more often.
Practical application in recent years show that the life of the oxygen sensor is well established, the potential difference between the carbon and the oxygen probe to measure the actual value is also unpredictable. Thus, a controlled atmosphere and sometimes because of the failure of the oxygen sensor without control, causing defects such as oxidation decarbonization. Our stage is often used periodically check its accuracy, is not conducive to the furnace fully automated, and sometimes even affect the normal production. |
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