For complex part geometry, hand grinding is one of finishing and super finishing process the most used in mechanical industry. Surface integrity is today one major concern for industrials. The surface integrity is defined by a set of important characteristics of ground surface as surface geometric parameters (roughness, …), mechanical behaviour of the subsurface (hardness, residual stress, …) and structural changes of the material in the near surface. High heat and pressure, high strain and strain rate observed during hand grinding process, strongly influence surface integrity. Therefore, the surface behaviour, in terms of resistance to corrosion and crack initiation depends on how the process was conducted. The purpose of this study is to understand the effects of thermal and mechanical plastic deformation induced on the surface of components. The action of the disc-grinding wheel on the workpiece is modelled by a moving heat flux on the surface. The challenge is to be able to find the shape and intensity of thermomechanical load entering the workpiece in accordance with the hand disc grinding process and taking into account specific parameters of the process. In a first part, a mechanical description of the action of the disc-wheel on the surface is proposed in order to develop an analytic formulation of the grinding power and the heat flux density. They are function of the disc-grinding wheel velocity, the feed speed and the applied forces. This expression is then used in a finite element modelling to perform thermomechanical simulations of the hand disc-grinding process. In a first stage, heating and cooling are computed. They give maximum temperature reached, temperature gradients and cooling kinematic. In a second stage, thermomechanical computation is conducted in order to compute residual stresses induced by this abrasion process. A discussion based on experimental results obtained by XRD method is then proposed and some local explanation are given on the way the material structure has changed leading to a structural hardening in the 50 first microns beneath the ground surface.

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