Recent research on cooling power of liquid quenchants in Japan

In Japan, the JIS silver probe, the ISO Inconel alloy probe and the other probes are used for determining the cooling power and the quality control of various quenchants. Recently, a lot of research on the cooling power and the evaluation of that power have been reported by many workers because of the growing demand for a higher quality of heat-treated products. This report outlines the recent research in Japan concerning the cooling power of liquid quenchants. COOLING CURVE TESTS have been used as the most useful means of testing the cooling power of liquid quenchants such as oils, water, and so on. During the 1950`s, Tamura studied the properties of many quenchants and clarified the cooling phenomena in quenching. Based on his detailed studies, the JIS method for the evaluation of the cooling power of oils was set in 1965. The cylindrical silver probe was adopted for the JIS method because of the following advantages. (1) No effect of the phase transformation. (2) No effect of the surface oxidization. (3) High sensitivity of the probe. (4) Excellent reproducibility.