MEASUREMENT OF QUENCHING INTENSITY, CALCULATION OF HEAT TRANSFER COEFFICIENT AND GLOBAL DATABASE OF LIQUID QUENCHANTS

This paper explains the need for a database of cooling intensities for liquid quenchants, in order to predict the quench hardness, microstructure, stresses and distortion, when real engineering components of complex geometry are quenched. The existing laboratory procedures for cooling intensity evaluation, using small test specimens, and Lumped-Heat-Capacity Method for calculation of heat transfer coefficient, are presented. Temperature Gradient Method for heat transfer calculation in workshop conditions, when using the Liscic/Petrofer probe, has been elaborated. Critical heat flux densities and their relation to the initial heat flux density, is explained. Specific facilities for testing quenching intensity in workshop conditions, are shown.The two phase project of the International Federation for Heat Treatment and Surface Engineering (IFHTSE), as recently approved, is mentioned.