Reprocessed waste sunflower cooking oil as quenchant for heat treatment

Abstract

The growing concern to minimize the use of petroleum derived mineral oil in heat treatment industries has led to the search for alternative eco-friendly quenchants. Although vegetable oils seem to be a viable option, the higher cost and inferior thermal and oxidation stability have limited their application in the heat treatment industry. The reuse of waste cooking oils for industrial heat treatment would not only make quenchants cost-efficient but also environment friendly. In this study, the cooling performance of waste sunflower cooking oil was assessed and compared with that of unused sunflower cooking and mineral oils. The waste sunflower oil was made suitable for quenching by cleaning and chemical treatment. The experiment to assess the suitability of reprocessed oil for quenching was conducted using an Inconel 600 standard probe according to ISO 9950 and ASTM D 6200 standards. The thermal history acquired while quenching of the probe was used to estimate the surface heat flux transients. The results indicated that the chemically treated waste sunflower cooking oil had a higher cooling performance than that of unused sunflower and the mineral oils. A good agreement was found between the heat flux transients and hardness data obtained with the quenched AISI 4140 steel probe. The simulation of temperature and hardness distribution indicated more uniformity along the length of the probe indicating more uniform cooling with chemically treated waste sunflower cooking oil. © 2020 Elsevier Ltd