Investigating machinability characteristics of Fe-C-Cu and Fe-C-Mo P/M low alloy steels through cylindrical grinding operation

Abstract

In the recent years of material innovation, Powder Metallurgy (P/M) materials have overwhelmed contribution in all industrial sectors. Machinability is a pre-requisite material characteristic to convert them into a functional part. In the present investigation, the effects of alloying elements and density on machinability of Fe–0.5%C plain carbon steels have been undertaken. Due to more industrial applications prospects, Fe-0.5%C-2%Cu and Fe-0.5%C-2%Mo low alloy steels have been considered, and cylindrical grinding operation has been used to study the machinability characteristics. For both P/M alloy steels, work speed, depth of cut and density are considered variable parameters to perform the operation using the L9 orthogonal array. The surface roughness value is assessed to ensure the effect of process parameters on machinability and to fix the optimal grinding conditions. The experimental results of Mo exhibit higher density (93.10%) and hardness (92 HRB) compared to the Cu added plain carbon steel, which has 92.15% and 91 HRB, respectively. The experimental results of the Cu alloyed plain carbon steel exhibits better machinability characteristics, 0.22 µm surface finish compared to the Mo alloyed steel with a 0.26 µm surface finish. The optimal working parameters for better surface finish achievable in both P/M low alloy steels are work speed of 90 rpm and depth of cut of 0.01 mm with the highest possible theoretical density.