Abstract: Based on the experimental measurement of the cooling curve of the ring gear made of 20Cr2Ni4A steel during the pressure quenching process under different flow rates and the calculation of the corresponding heat transfer coefficients, corresponding finite element numerical simulation was carried out, and the effect of different flow rate combinations on temperature field distribution of the ring gear during pressure quenching process was studied. The results show that the heat transfer coefficients corresponding to 189-1136 L/min flow rates all show a trend of increasing first and then decreasing with the decrease of temperature, and the maximum value of heat transfer coefficient increases with the increase of flow rate. Among the four representative flow rate combinations, the slow-fast-fast flow rate combination can better reduce the temperature difference between the inside and outside of the ring gear. Comparing with the temperature measurement results, it is found that the simulation results are in good agreement with the experimental data, and the established pressure quenching temperature field model is reliable, which can provide theoretical guidance for optimization of the pressure quenching process.

Key words: pressure quenching, numerical simulation, 20Cr2Ni4A steel, ring gear, temperature field