Cooling Characteristic of Polymeric Quenchant: Calculation of HTC and Prediction of Microstructure and Hardness

The present paper discusses the influence of experimental conditions on the quenching performance of poly(2-ethyl-2-oxazoline) (PEOX) aqueous solutions used as cooling medium, using a standard ISO Inconel alloy probe for measurements of cooling rate. The evaluation procedure is demonstrated on characterization of cooling power of water-based polymer (PEOX) solutions by using different concentration, temperatures, and agitation conditions of the cooling media. The results show that the different experimental conditions have a significant effect on the cooling performance. The polymer quenching mechanism and the comparative cooling characteristics of water, and water-based PEOX polymer solution with concentrations from 2.5 to 15 wt.% were discussed. The study involved the assessment of the quenching severity by calculating the hardening power (HP) via empirical equations. Calculation of heat transfer coefficients as well as prediction of microstructural constituents and the hardness profile in a cross-section of steel sample were carried out on the basis of inverse calculation from the recorded cooling curve.