Comparison of Cooling Behaviour of Carbon Steels in Polymer, Oil and Carbonated Quench Media

Abstract

Cooling behaviour of steels in quench media is of great importance as this controls phase transformations, heat transfer and the stress evolution. The heat extraction ability of each quenchant is different because of varying thermophysical properties and wetting behaviour. The quenchants should be selected in such a way that they provide uniform cooling of steel. In the present investigation, quenching experiments were carried out with Inconel 600, EN19, EN24, EN31 steel grades in distilled water, servo oil, carbonated distilled water and 10% PAG. The cooling curve analysis of the quenching process was carried out with temperature data recorded during quenching. This measured temperature–time data were used to estimate the heat flux by inverse modelling without considering the effect of phase transformation. The crack propensity was quantified using the quench uniformity ratio. The hardness distribution observed during quenching in carbonated distilled water was observed to be more uniform compared to other quench media. © 2019, The Indian Institute of Metals - IIM.