MACHINED SURFACE OF FCD 700 DUCTILE CAST IRON IN A DRY TURNING ENVIRONMENT USING CARBIDE TOOLS

Machining is one of the most important processes in producing automotive components such as difficult to cut cast iron grade FCD700. Trying to improve the machining technique, for the benefit of humanity and the environment, is a continuous process. This paper presents an environmentally-friendly method of turning FCD700 cast iron using a carbide tool without coolant. The turning process was carried out in three types of dry conditions, i.e. without air, in chilled air and in normal air. The turning parameters studied were cutting speed (100-300 m/min), feed rate (0.1-0.4 mm/rev), and depth of cut (0.2-2.0 mm). Results show that the average surface roughness (Ra) was greatly affected by the feed rate, while the effect of depth of cut was negligible. A low Ra value was produced at a high cutting speed, especially at a medium air temperature of 10 deg C. The Ra obtained deteriorated with cooler chilled air at -2 deg C, when compared to cutting in an environment without air. A high feed rate produced a coarser surface finish at the beginning of the cut, but as the tools wore out the machined surface topography remained similar, regardless of the value of the feed rate used.