抄録
In the present research, the cooling power of various kinds of the quenching media was measured more accurately than in the result of the other similar methods, by using a specially devised apparatus. Consequently, the so-called "three stages" in cooling on the cooling curve of quenching media was explained and their "characteristic points" were precisely determined. Thence a "temperature-cooling velocity curve" was plotted for each quenching medium and its threefold tendencies were classified. Besides, the effect of the temperature of quenching media on the cooling power and on the differential cooling velocity were explained.
