Title: Effect of tool wear on white layer thickness and subsurface hardness on hard turned EN31 steel
Authors: Gaurav Bartarya; S.K. Choudhury
Addresses: Mechanical Engineering Department, Harcourt Butler Technological Institute, Kanpur, U.P. 208002, India ' Mechanical Engineering Department, Indian Institute of Technology, Kanpur, U.P. 208016, India
Abstract: The effect of abrasive wear of the tool is predominant on hard turned components as it induces surface integrity-related issues like white layer and variation of hardness in subsurface region. A white layer limits the fatigue life of hard turned part. The present work is an experimental analysis of finish hard turning of hardened steel using uncoated cubic boron nitride tool insert with predefined flank wear. The work aims to analyse the effect of cutting speeds and tool flank wear on the white layer thickness, variation in hardness across the subsurface, and the surface roughness through response surface methodology and critical examination of the micro-images. These surface and subsurface properties were found to be severely affected by the flank wear as well as the cutting speed. Also, a viable concept could be developed to produce controlled surface properties or tailor-made surfaces even when machining with the highly worn tools.
Keywords: hard turning; flank wear; surface integrity; subsurface microhardness; tool wear; white layer thickness; EN31 steel; fatigue life; cubic boron nitride; CBN tool inserts; cutting speed; surface roughness; response surface methodology; RSM; surface quality.
International Journal of Machining and Machinability of Materials, 2016 Vol.18 No.5/6, pp.483 - 500
Received: 25 Apr 2015
Accepted: 01 Jan 2016
Published online: 08 Sep 2016 *