Compilation and Validation of Heat Transfer Coefficients of Quenching Oils

When hardening steel components in industry hardening oils are commonly used as quenchants. To be able to predict the result after hardening using FEM-calculations it is of great importance how the cooling is described. Heat transfer coefficients are used as boundary conditions on components that shall be evaluated. The cooling ability for quenching oils is varying with parameters such as temperature, agitation and condition of the oil.

In this study four different oils from the industry have been investigated. Cooling curves have experimentally been compiled with ivf SmartQuench®. Based on the cooling curves heat transfer coefficients have been calculated with the software SQIntegra. The cooling ability variation for the different oils and conditions was analyzed with regard to selected characteristics such as heat removal capacity and hardening power.

Parameters such as temperature, agitation, volume and condition of the oil are affecting the heat transfer coefficient. Temperature and agitation had a relatively strong effect on the cooling performance while the effect of testing beaker volume or condition of the oil showed a smaller or no general trend.