油是应用很广泛的淬火介质。近年来,随着科学技术的发展,热处理用油出现了真空淬火油、光亮淬火油、快速淬火油、等温(分级)淬火油等新品种,这些油除进行常规粘度、闪点、酸值、灰分、残碳、水分、理化分析外,作为热处理用油,还需进行特定项目评定,如油的冷却速度、热氧化稳定性、光亮度和饱和蒸汽压等。这些评定对于研制新油和在生产中分析油的质量都起重要作用。国外对某些评定方法及评定装置多已 Oil is widely used quenching medium. In recent years, with the development of science and technology, new varieties such as vacuum quenching oil, bright quenching oil, rapid quenching oil and isothermal quenching oil have appeared in the heat treatment oil. These oils have the following properties: conventional viscosity, flash point, acid value, Ash, residual carbon, moisture, physical and chemical analysis, as a heat treatment oil, but also need to carry out specific projects such as oil cooling rate, thermal oxidation stability, brightness and saturated vapor pressure. These assessments play a key role in developing new oils and in analyzing the quality of the oil in production. Some foreign assessment methods and assessment of many devices