Investigation of Tool Wear Model an‎d Extent in Dry Turning of Ductile Cast Iron with Workpiece Preheating

12/16/2025 12:00:00 AM

Ductile iron is widely utilized in the automotive, machine manufacturing, an‎d general engineering industries due to its desirable mechanical properties, including high strength, toughness, an‎d wear resistance. However, its microstructural nature, particularly the presence of spherical graphite an‎d possible hard phases, poses significant challenges in machining processes, such as short tool life an‎d high wear rates. This research systematically investigates the effect of workpiece preheating on chip morphology an‎d tool wear in the turning of ductile iron, aiming to eva‎luate an‎d enhance its machinability. Experiments were conducted in eight main groups: four without preheating an‎d four with a constant preheating applied to the workpiece at 200oC ti 300oC. Independent variables included cutting speed (ranging from 120 to 400 m/min) an‎d feed rate (0.1 to 0.25 mm/rev). The results indicated that under non-preheated conditions, increasing the cutting speed shifted the chip morphology from soft discontinuous to shear-discontinuous chips, which was accompanied by a significant increase in tool wear. At high cutting speeds, the diffusion wear mechanism was identified as the dominant tool degradation mode, leading to considerable wear (up to 4.169 mm2). In contrast, preheating the workpiece had a notable impact on the machining process; this strategy reduced cutting forces an‎d effectively controlled heat at the tool-chip interface by softening the material in the cutting zone. The consequence of this thermomechanical control was a considerable improvement in chip morphology (producing more ductile chips with controlled flow). Specifically, under optimal conditions (cutting speed of 350 m/min an‎d preheating at 200oC to 300oC), wear was reduced to 0.214 mm2, representing an approximately 93% reduction compared to the non-preheated equivalent condition (3.034 mm2). Ultimately, this research confirms the importance of preheating as an effective an‎d practical strategy for extending tool life an‎d improving productivity in the machining of ductile iron.

چدن داكتيل , پيش‌گرمايش , قابليت ماشينكاري , مورفولوژي براده , سايش نوك ابزار , سايش نفوذي , بهره‌وري

Ductile Cast Iron , Preheating , Machinability , Chip Morphology , Crater Wear , Diffusion Wear , Productivity

Javad Doust Mohammadi

Dr. Seyed Ali Niknam