关键词: 真空气淬, 冷却模式, 流场, 温度场, 淬火畸变

Abstract: Combination of temperature curve measurement and heat treatment simulation was adopted to establish a simulation analysis model for the temperature and flow fields inside the vacuum gas quenching process of thin-walled combustion chamber shells with large aspect ratios under multiple-charge furnace loading. In order to reduce the quenching distortion of the shell, a method of changing the air outlet combination of the equipment was used to improve the flow filed and temperature field distribution in the inflation and domestic circulation stages of the quenching process. The results show that under the condition of the original four air outlets and charging 3 shells, due to the structural characteristics of the equipment itself, there are differences in front and back surfaces of the combustion chamber shell and differences in the upper and lower regions of the furnace, and the overall cooling rate of the shells at different positions follows the order of upper windward＞lower windward＞upper leeward＞lower leeward. After adjusting the cooling mode, the results show that the effect of the three air outlets model is similar to the original model, and the effect on the flow field and temperature field is minimal, while the one air outlet model has a greater impact. Under the one air outlet model, the cooling rate of the leeward side of the shell is increased by more than 18%, and the temperature difference is reduced by more than 31.5%, which improves the temperature uniformity of the shell. The distortion degree of the product is reduced by 22.2%, and the mechanical properties meet the requirements of design index, indicating that the optimized mode has a little effect on the mechanical properties of the combustion chamber shell.

Key words: vacuum gas quenching, cooling mode, flow field, temperature field, quenching distortion