An Investigation of Optimum Cutting Conditions in Face Milling Mold Steel Affect the Surface Roughness and Tool Wear
The purpose of this research was to investigate the effect of the main factors on the surface roughness in mold steels face milling by carbide tool for results obtained from the analysis used in the manufacture of molds and other parts of the industry. The etching experiment using semi-automated milling machine Obraeci Strojie brand FGV 32 model. Concerning the material was steel grade AISI P20 mold with a hardness between 280-325 HB which used to insert carbide tool. The factors of a speed, feed rate and depth of cut were study. Preliminary experiments showed that the depth does not affect the surface roughness fix depth of cut at 0.5 mm. The experimental revealed that the factor affecting surface roughness was feed rate and speed. The roughness value trenced to reduce at lower feed rate and greater speed. It was possible determine a facing condition by means of the equation Ra = 1.29 - 0.000654Speed + 0.00305Feed rate leading this equation goes to use is in limitation speed 500-1,000 rpm. at feed rate 160-315 mm/min. From the experiment was confirming the result of a comparison between the equation and the percent accuracy with the margin of error. The result from the experiment of mean absolute percentage error (MAPE) of the equation of surface roughness was 3.27% which was less than the margin of error and was acceptable. The pattern of wear was similar to mechanical fatigue cracking. It may be due to the verious tip of the cutting tool or an impact and flank wear as cutting tool materials resistant to wear less.