焼入冷却剤の研究（第2報）活動写真による焼入冷却過程の観察

抄録

We filmed the phenomena during the quenching into several liquids, simultaneously recording the cooling curves by the quenching apparatus as shown in the 1st report. Men can observe both the gas bubbles and convection of liquid by filming the specimen and its shadow. In this way we could observe the cooling curve and the bubbles of evolved gas, convection of the liquid and the temperature of specimen at the same time. The cooling process in common liquids like water, oil, ect. generally has four stages and the length of time and temperature of each stage depend upon the kind of liquid. In the 1st stage,the cooling is done by the small amount of liquid which is in contact with the specimen until it reaches the boiling point. This stage was not present when the liquid had high viscosity, contained dissolved gas,or the bath temperature is near the boiling point.In the 2nd stage,the cooling is slow. The specimen was covered with vapor film in this stage. This stage was not present in the solution of non-volatile solute like 10%NaCl aq. In the 3rd stage,the cooling was most rapid.The liquid was boliing violently in this stage.This stage is not present in the solution of wsterglass (5.17%Na₂O). In the 4th stage,the cooling is done slowly in convection of liquid. We show such a cooling process in several quenching media of different kind by means of corresponding the moving picture with the cooling curve in each case.