焼結銅鋼の焼入れ特性について

抄録

In this work, the continuous cooling transformation diagrams of the Fe-Cu-1.0%C sintered Cu steel containing up to 6.5%Cu were investigated, and the effect of Cu on the critical cooling rate was made clear. Subsequently, in order to investigate the difference between the hardenability of the normal wrought steel and that of the sintered steel, the continuous cooling transformation diagram of the eutectoid carbon steel practically free from impurities, produced by vacuum melting method, was studied.
The results obtained were summarized as follows:
(1) The critical cooling rate of the Fe-1.0%C binary sintered compacts was as fast as 1100°C/sec, indicating poor hardenability.
(2) The critical cooling rate of the Fe-Cu-1.0%C ternary sintered compacts became slower with increasing Cu content. For example, it was 140°C/sec in the case of the Fe-6.5%Cu-1.0%C ternary sintered compacts whose composition was nearly the same as the Fe-Cu-C ternary eutectoid composition.
(3) The critical cooling rate of the normal wrought Fe-0.77%C steel with 0.75%Mn and 0.2%Si was 150°C/sec, while, it was 900°C/sec in the case of the Fe-0.77%C steel practically free from impurities.