Calibration of emissivity value of 18CrNiMo7-6 steel and study on cylindrical grinding temperature
To study the variation rule of workpiece temperature concerning machining parameters in the cylindrical transverse grinding process of gear steel,18CrNiMo7-6 gear steel was selected as the workpiece material,and a CBN grinding wheel was used as the grinding tool.An infrared thermal imaging instrument was used to detect the temperat-ure during the grinding process.A calibration scheme of thermal emissivity value,incorporating an additional air cur-tain device,was proposed.The high-speed airflow generated by the air curtain was used to slow down the entry of ex-ternal air into the heating furnace,preventing the oxidation of samples during calibration,thus ensuring the accuracy of the emissivity value calibrated under high-temperature conditions.Based on the test results,the influence of workpiece speed Vw,workpiece grinding depth per revolution fa,grinding wheel grain size dg,grinding wheel diameter ds and grinding width b on the temperature was analyzed.The workpiece grinding depth per revolution fa was identified as the most significant factor affecting the temperature change.The empirical formula between grinding temperature and aforementioned test parameters was obtained by fitting,with an error of 9.27%.The test measurement results of grind-ing temperature were compared with those derived from the theory of a moving heat source,Rayleigh distribution mod-el and dry grinding heat distribution ratio model,resulting in a deviation of 8.51%.
infrared temperature measurementthermal emissivityCBN grinding wheeltemperature prediction mod-elRayleigh distribution model
万方数据
维普
