Volume 5, Issue 10 (November 2008)
Starch-Based Quenchants as an Eco-Friendly Alternative to Quenching Oil
Petroleum-based mineral oil is a commonly used quenching media for heat treatment, due to its moderate cooling rate which provides minimum distortion to components. However, quenching oil is also associated with several environmental liabilities such as oil fumes, fire hazard, oil spills, leaking underground storage tanks, and waste oil disposal liabilities. As a result, the use of oil as a quenching media is being discouraged and is listed as one of the significant concerns in the Vision 2020 technology roadmap of the ASM Heat Treating Society. In the present work, starch-based quenchants have been developed as an eco-friendly alternative to oil quenchant. It has been shown that by tailoring the composition, the peak cooling rate as well as peak temperature can be optimized to provide the required cooling characteristics for a wide range of materials. Industrial trials on tool steels have shown cooling characteristics and uniformity in hardness of starch quenching similar to oil quenching.