On the near-dry machining of SAE 300M steel: experimental and numerical investigations

Abstract

Cutting fluids are sources of environmental and health hazards while dry machining limits the cutting speeds, leading to productivity loss. The performance of minimum quantity lubrication (MQL), flood and dry conditions was investigated herein in turning of SAE 300M steel. The performance criteria are tool wear, surface roughness, and machining forces. Three cutting speeds were investigated. The experimental results indicated that MQL can improve tool life by up to 90% over dry cutting and there is a cutting speed beyond which MQL improved tool life over flood conditions. Experimental and 3D-FEM results for dry condition were in reasonable agreement, mainly for the cutting force. The thrust force is predicted within 15% for speeds lower than 550 m/min and 38% at 700 m/min. The correlation between the predicted temperature distributions on the insert and the tool wear pattern are presented. The predicted and experimental tool-chip contact locations are also compared.