| abstract |
The invention provides a water-soluble quenching medium suitably usable for quenching of metal, which can prevent quenching cracks and quenching ununiformity while having good hardenability. The medium comprises (A) a polyalkylene glycol having a weight average molecular weight of from 10,000 to 100,000 and/or its derivative, (B) a glycol ether having a weight average molecular weight of 1,000 smaller, and optionally (C) an alkylene glycol having a weight average molecular weight of 1,000 or smaller, (D) an alkali metal carboxylate, and (E) an organic amine compound having a weight average molecular weight of 1,000 or smaller. |