| 摘要 |
PROBLEM TO BE SOLVED: To provide an aqueous cooling liquid effective for the suppression in the generation of incomplete hardening.SOLUTION: Provided is a cooling liquid made of a water solution, in which the concentration of a polyalkylene glycol (PAG) based water soluble cooling agent is 0 to 20 mass%, and further sodium carbonate is included therein. In this way, by the addition of the sodium carbonate, the cooling performance of the cooling liquid can be improved. In a low temperature region where hardening cracks are easy to occur upon hardening treatment, cooling velocity is reduced or is hardly changed with the case where sodium carbonate is hardly added, and, on the other hand, in a high temperature region where incomplete hardening is hard to occur, cooling velocity can be increased in the high temperature region. Thus, it is effect for the suppression in the generation incomplete hardening.SELECTED DRAWING: Figure 1 |
