球状黒鉛鋳鉄のチル臨界冷却速度と黒鉛粒数 Nodule Count and Critical Cooling Rate of Chill Formation of Molten Spheroidal Graphite Cast Iron
The chill forming tendencies of molten spheroidal graphite cast iron treated by the sandwich method and inmold method are compared. The cooling rate at the time of chill generation (the critical cooling rate) was used for comparing the chill forming tendencies. The cooling rate measured was the maximum cooling rate after solidification. The critical cooling rate for chill formation for the inmold method was 18K/s. which is very large when compared to the 3K/s of the sandwich method. Thus, it was inferred that the inmold method has a low chill-forming tendency. The graphite nodule counts were measured and it was found that as the cooling rate increases, the nodule count also increases. However, when the cooling rate increases above the critical cooling rate, the nodule count decreases. The nodule count, as obtained during the critical cooling rate, is the critical nodule count. The critical cooling rate is the characteristic value of molten iron, and, the critical nodule count is the characteristic value of the cooling rate. Hence, it is suggested that a comparison of the critical cooling rates be made to compare the chill forming tendencies of various molten irons.
- 鋳造工学 = Journal of Japan Foundry Engineering Society
鋳造工学 = Journal of Japan Foundry Engineering Society 69(6), 491-498, 1997-06