ANALYSIS OF SURFACE ROUGHNESS MILLED OF STEEL AISI 1045 USING X-BAR AND R CONTROL CHART

The steel milling AISI 1045 has been gaining prominence in industry in recent years as it allows machined parts to be obtained with low-cost inserts. However, to ensure the final product quality, it is important that the milling for machining procedure be well planned in order to the cutters have their wear minimized in the process, as well as a considerable productivity rate with a zero occurrence of reworked parts or scraps. Thus, this paper presents a study about the quality of the machined surface on the end milling process of AISI 1045 steel using titanium nitride (TiN) coated carbide inserts, optimized for a combined design, using Design of Experiments (DOE). Statistical Process Control (SPC) is applied to analyze the process variations using X-bar and R control charts. The objective of this study is to identify the optimal combination of the input setup such as cutting speed (Vc), feed per tooth (fZ), work penetration (ae) and machining depth (ap) that is capable of minimize the process variation. The response measured is the roughness parameter Ra, observed under the influence of cutting fluid, tool wear, concentration and flow of the cutting fluid as noise. The obtained result was the stability of the Ra roughness for the AISI 1045 steel in end milling process, which is not influenced by noise variables due to Robust Parameter Design used in this study.