Explain the Effect of Cutting Speed
Increase in cutting speed improves the surface finish due to the continuous reduction in built up edge. The curve a represents the machining of steels except high alloy grade steels. In the beginning the surface roughness increases when cutting speed changes from V1 to V2. This is due to the beginning of built up edge formation which reaches its maximum value at the cutting speed V2. Then the formation of built up edge is reduced due to the rise in temperature and at cutting speed V2 it almost disappears. This reduces the height (H) of micro irregularities. There is almost no hump on the curve B obtained in machining high alloy steels. Non-ferrous metal and cast iron, this is due to the completed absence of built up edge formation.