Understanding of polymer quenchant (polyalkylene glycol) characteristic during quenching process of tool steels

摘要

The polymer quenchants minimise the cooling rate, so that the possibility of distortion and cracking is reduced. This study focuses on the effects of air and polyalkylene glycol (PAG) on the cooling characteristics of 1.2379 and 1.2080 tool steels. In quenching, different concentrations (10%/20%/30%) of PAG were used. The effect of cooling characteristic of PAG was observed using a digital image processing during the experiments and the curves indicating the cooling gradient of the tool steels as a function of time were plotted. The microstructural analysis of tool steels was carried out using light microscopy (LM). It was concluded that: ⅰ) as the PAG percentage increased, the full cooling time of tool steels increased; ⅱ) 1.2080 tool steel having Mo and V had higher amount of carbides than those of 1.2379 tool steel; ⅲ) the both tool steels quenched in 30% PAG exhibited coarser carbides than cooled in air.