Resumo:
The free-machining steels are known by having a good machinability due to easiness
of chip formation. The characteristic of a good machinability is determined, essentially, by the
chemical composition of the material with high sulphur contents and other elements as, for
example, the lead. It is important to point out that there are others factors that influence the
machinability of steels such as the presence of the residual elements chrome (Cr), nickel (Ni)
and cooper (Cu). However, concerning to the residual elements (Cr, Ni and Cu), the influence
of their contents in the machinability of these steel is unknowned. Thus, this work studies the
influence these elements in the machinability of the ABNT 12L14 steel, through short
duration tests with high-speed steel and cemented carbide tools. The results showed that the
residual elements have a significant influence in the tool life. The electric power and the
roughness parameter Ra were not influenced by the variation of the residual elements. The
tests were planned according to technique of project of experiments (DOE) and the results
analyzed using statistical procedures fundamentals.
