Heat Transfer Properties of a Series of Oxidized and Unoxidized Vegetable Oils in Comparison with Petroleum Oil-Based Quenchants

Vegetable oils, especially soybean oil, exhibit substantially poorer thermal-oxidative stability than commercially available petroleum oil quenchant formulations. Therefore, to achieve any commercially interesting performance, vegetable oils must be stabilized by the addition of antioxidant inhibitors. This work describes the ability of two commercially available antioxidants, Irganox L 57 and Irganox L 109, to stabilize soybean oil against thermal-oxidative degradation. In addition, the effect of antioxidant stabilization on quenching performance was evaluated by determining the profile of heat transfer coefficient variation throughout the quenching process at different times after being subjected to an accelerated thermal-oxidation aging test. The results of this work are discussed here.