Comparison of Structure and Quenching Performance of Vegetable Oils

Abstract

This work describes the physical property analysis and molecular structural characterization by gas chromatography and nuclear magnetic resonance spectroscopy of cottonseed, sunflower, corn, canola, and soybean oils. To assess the relative quenching performance of these different vegetable oils, cooling curve analyses was conducted according to ASTM D6200 at series of quenchant bath temperatures: 40, 60, 80, 100, and 120°C. For comparison, cooling curve analysis under the same testing conditions for a commercially available conventional and an accelerated petroleum oil-based quenchant was also performed. This work showed that although the different vegetable oils exhibited significantly different molecular structures, their viscosity and viscosity-temperature behavior was comparable. Also, the quenching performance of the different vegetable oils, while not identical, was not significantly different from each other. However, it is noteworthy that the vegetable oils did not exhibit classical film boiling or nucleate boiling behavior during quenching. For this reason, the quenching performance was different from either the conventional or the accelerated quench oils, which exhibited the expected film boiling, nucleate boiling, and convective cooling behavior. The relative difference in quenching performance between petroleum oil derived quenchants and vegetable oils is discussed in detail.

Using Thermal Gradient Measurements to Compare Bath Temperature and Agitation Effects on the Quenching Performance of Palm Oil, Canola Oil and a Conventional Petroleum Oil

“…11 Recently, the relative quenching performance of an extensive series of vegetable oils has been studied, using the standard ISO 9950/ASTM D6200 12.5 mm diameter by 60-mm length cylindrical Inconel 600 probe with a single TC inserted to the geometric center. 12 In addition to extensive cooling curve time-temperature behavior of these quenchants, heat transfer characteristics were quantified using this probe as well. 13 For industrial quenchant formulation, vegetable oils require the addition of an antioxidant.…”

“…15 This was attributable to the substantially lower polyunsaturated triglyceride components in the chemical composition of the oil. The comparative quenching behavior of palm oil was not included in earlier de Souza studies 12,13 but was subsequently performed by Belinato, Canale, and Totten 15 and Said et al 16 Recently, extensive heat transfer characterization of palm oil and coconut oil versus a petroleum oil was reported by Kobasko et al, who used the small 12.5-mm diameter multiple-TC probe for this work. 17 Until now, most of the recent published work characterizing the quenching performance of vegetable oils has been performed with the small 12.5-mm diameter Inconel 600 probes described in ISO 9950 and ASTM D6200.…”

Assessment of Cooling and Heat Transfer Properties of Quenchants with MATLAB

“…Recently, Carvalho et al [5,6]; Belinato, Canale, and Totten [7]; and others have similarly examined the quenching behavior of vegetable oils using cooling time and rates. These cooling curve data parameters were also compared to typical petroleum oil quenchants, and the results similarly indicated very short, if observable, film-boiling regions for vegetable oils in general when compared to petroleum oil quenchants.…”

Quenchant Cooling Curves, Rewetting, and Surface Heat Flux Properties of Vegetable Oils

“…In more recent work, de Souza et al [10,11], Prabhu and co-workers [12,13], and Agboola et al [14] extensively characterized a wide variety of seed oils, such as corn oil, canola oil, sunflower oil, soybean oil, and others, by cooling curve analysis using small (typically ≤12.5 mm) cylindrical probes usually constructed from Inconel 600 or a stainless steel. In addition to the characterization of cooling time and cooling rates of these oils, their heat transfer properties were determined using either a simplified computational methodology [15,16] or finite element analysis [11][12][13].…”