In order to clarify the machinability of calcium deoxidized 0.45% carbon steel, the effect of chemical composition on the machinability was investigated in turning and drilling.
Experimental results in turning with carbide tool showed that the tool wear depends on contents of aluminum, calcium and sulfur in steel, and it is suppressed when the content of sulfur is more than 0.035% and that of aluminum is less than 4.3 times of calcium content in steel.
In this case, a thin oxide layer containing some sulfide phase is always found on the tool face and it is supposed that this prevents the tool wear.
In drilling with high speed steel tool, higher sulfur content in steel is favorable for tool life. But no effect of aluminum or calcium is observed.
