Abstract
Free machining steel, because of its high levels of sulfur, manganese, and lead, is known for its good machinability. These three residual elements, which act to guarantee easy chip formation, are not, however, acting alone to influence this steel's good machinability. It is their influence, certainly, that is best understood, but researchers have yet to adequately understand the influence of three other residual elements, chrome (Cr), nickel (Ni), and copper (Cu). The present study aimed to determine some measure of the impact of these elements on machinability. In particular their influence on the machinability of AISI 12L14 steel was investigated. Employing the design of experiment (DOE) technique, the tool life was measured for nine batches of steel, each containing, within the tolerable amount, different levels of chrome, nickel, and copper. By analysing the results with statistical tools, it was found that levels of their presence do indeed influence the machinability of AISI 12L14 steel. Therefore, even within the variability allowed by the standards, steel-makers should manage the levels of these residual elements.