Method of quenching metals

摘要: A method of quenching metals is described, comprising immersing said in a oil composition comprising: (a) base oil, and (b) compound represented by the general formula (1) or (2) as described below. ##STR1## (wherein all symbols are same defined claims). The use results formation black coating layer on metal, producing those metallic articles having improved characteristics, such good lubricity rust preventive properties.