Selection Of The Orthogonal Array In Turning Of AISI D2 Steel

In this paper the selection process of the orthogonal array in turning of AISI D2 steel is discussed, the outermost 2 mm thick oxide layer was removed from the surface of all the specimens (D2 steel) by rough turning with PVD coated ceramic inserts. Longitudinal turning tests were conducted on the specimens held on rigid and high precision CNC lathe using coated ceramic inserts. Turning tests have been performed for various combinations of cutting speed, feed rate, and depth of cut. The design of experiments was based on Taguchi method. The average values of tool flank wear (VB) and surface roughness (Ra) were measured at the end of each experiment. The average flank wear was monitored with the help of a tool maker’s microscope and surface roughness was measured with a surface roughness analyzer. The experiments were interrupted at regular intervals to record average values of tool flank wear and surface roughness of the machined surface. Each single pass was carried out over an axial cutting length of 190 mm. The experiment was terminated when either of the following two conditions was reached: Condition 1: VB≥200 μm; Condition 2: Ra ≥ 1.6 μm. For this case the Orthogonal Array of L (OA)₉ (3)³ has been selected, Where, 9 means number of trials, (3) means number of levels of each factor, ( )³ means number of factors.