高压气淬过程的数值模拟

应用有限体积法建立了数学模型,对高压气淬过程中气体的速度场、气体和工件的温度场以及工件内部的组织场进行了耦合计算,针对一组小棒料高压气淬的模拟结果,分析了气体流动、工件温度与相变各自的影响因素以及它们之间的相互影响,指出几何模型准确建立的重要性.另外通过模拟结果与实测冷却曲线的比较,该模型基本反映了高压气淬过程,其中加入相变计算能更符合实际,并且还能预测出工件的最终组织.应用本文中的相变计算模型,相变的计算结果与工件金相照片中的实测结果基本吻合.

Numerical Simulation of High Pressure Gas Quenching Process

In order to study high pressure gas quenching process completely and exactly, the numerical model was established by use of the finite volume method to coupled compute gas velocity, temperature field of gas and workpiece and phase transformation inside workpiece during high pressure gas quenching process. Aimed at simulated results of a batch of steel bars after high pressure gas quenching, the respective effect factors of gas flow,workpiece temperature and phase transformation and the influence among each other were analyzed. The correct geometry model is very important during numerical simulation. According to comparing the simulated cooling curves with the experimental data, it is shown that the numerical model used is adapted to the high pressure gas quenching process. Moreover, the model with phase transformation is much exacter than without phase model to simulate the practical quenching process. Using the phase transformation model,the simulated microstructure is agreed mainly with that of the experiment.