Ca脱酸鋼のBelag形成に及ぼす超硬工具材質の影響

抄録

The effect of improving machinability of Ca-deoxidized steels in carbide tool machining operation is widely known. It has been proposed that oxide inclusions in steels,which works as “belag” on the tool surface during machining operation,has been responsible for this effect. In this paper,we have investigated the influence of carbides tool material on belag formation of Ca-deoxidized steel. Oxide inclusions in Ca-deoxidized steel were similar to the chemical composition of gehlenite,which has a lower melting point than oxide inclusions in Al-killed steels,namely corundum. In the P-type carbide tool including (Ti,W)C component,the surface of the worn rake face was uneven because of the difference in wear rates between WC and (Ti,W)C carbide particles in this tool. On the other hand,in the K-type carbide tool without (Ti,W)C component,the worn surface was flat and the oxide layer was not observed on the worn rake face. It was confirmed that the belag was formed by oxide inclusions of gehlenite component piled on the uneven surface during cutting process.