Ca脱酸鋼における酸化物系介在物とBelagの微細組織

抄録

The effect of improving machinability of Ca-deoxidized steel in carbide tool machining operation has been widely known. It has been proposed that oxide inclusions, which would work as “Belag” on the tool surface during machining operation, in steels has been responsible for this improvement effect. In this study, the micro structure of oxide inclusion in Ca-deoxidized steel and Belag formed during turning was analyzed using transmission electron microscopy (TEM) analysis. Oxide inclusions and Belag were identified crystalline gehlenite using TEM. By synthesized oxide similar component of Ca-deoxidized steel's inclusion, it was clarified that the hardness of gehlenite around 700°C was soften by transition from amorphous to crystalline phase at 1100°C heating. It was confirmed that Belag was formed on tool face easily because the crystalline oxide inclusion in Ca-deoxidized steel was soften appropriate hardness by cutting temperature rising during cutting process.