Polymer Quenching as a Sustainable Solution using a Retrofit Oil Tank

Sustainable solution to quenching technology is required due to the pressing need for environmental concerns. Traditional quenching like oil and water for hardening of steel components requires extra tempering process to achieve the desired hardness, costlier waste management leading to high operational cost. Moreover, due to environmental concerns, safety of workers, fire hazards, hazardous wastes, release of toxic fumes, researchers are working on viable alternative quenching technologies. The objective of the research work is to minimize quench cracks, improve hardness, and improve microstructure properties under a safe environment. The current research work is conducted to validate the use of "aqueous solution of polymers" i.e. HI quench P50 as a quenchant used on quenching of AISI 4140 steel components using 10%, 15% and 20% concentration with different agitation speed of 750 rpm and 900 rpm in a retrofit oil tank quench bath maintained at a temperature of 40°C– 45°C. Lab trial and two production trial were conducted to establish the effectiveness of the process for large industrial setting. The polymer quenching was compared with oil quenching in terms of mechanical and microstructure properties. It was found the polymer quenching offered crack-free components, enhanced hardness, prescribed microstructures and better surface finish in a smoke free environment. Polymer quenching technology offered a safer environment to workers along with less pollutant discharged to the environment, thereby reducing the overall cost of the heat treatment process.