Analysis of Industrial Quenching (Air Transfer + Oil Immersion) and the Cooling Regimes after Immersion

Standard laboratory test methods are useful to compare the cooling performance and cooling regimes of different quenchants under controlled environments where quenching occurs almost immediately. In reality, many industries still rely on systems that require transferring through air from the austenizing furnace into the quench tanks while the components are held on special rigs through the process. In the present project, an industrial process requiring air transfer before immersion in low viscosity oil was assessed by utilizing special quench probes capable to replicate the non-homogeneous condition before immersion. The heterogeneity of the system and the influence of the heat treatment rig were captured by modifying the position and orientation of the quench probes on the assembly. Multiple characteristic points were identified during the boiling stage due to its physical significance to produce time dependent analytical curves build up through piecewise polynomial interpolation while an optimization algorithm models the convective stage. Such data was then used to inverse identify the boundary conditions in the form of heat transfer coefficients of the different cases. Results indicate that the phenomena occurring after immersion in hybrid quenching differs from laboratory results thus demonstrating the significance of characterizing the actual industrial process.