Depth and Lateral Variation of Machining-Induced Residual Stress for a Nickel Base Superalloy

Abstract

This paper investigates the variation of residual stress with depth and radial location in a nickel base superalloy, RR1000, introduced by face finish turning. X-ray diffraction stress measurement has revealed that the hoop stress at the surface becomes less tensile towards the centre of the face, whilst the level of radial sub-surface compression increases. The unstrained lattice spacing d0 and the diffraction peak width (FWHM) were used to make inferences regarding the thermal excursion and the plastic work, respectively. It was found the increase in the compressive stress from the outer towards the inner radius was associated with an increase in thermal excursion.