Productivity of flap wheel grinding after shot peening

The purpose of the paper is to develop a mathematical model of removed material amount formation when flap wheel grinding of the surface subjected to shot blasting that provides a stable quality of the surface in terms of the roughness parameter. Shot peening is widely used when forming long panels and skins. Shot peening results in the formation of a specific microgeometry of the treated surface, whose feature is numerous shot indents of various diameters and depths. The presence of these indents leads to the increase in surface roughness parameters. Therefore, after shot peening it is mandatory to perform surface grinding by a flap wheel for partial removal of indents - the results of shot peening which are much larger than microroughness dents. The value of the assigned allowance for grinding depends on the requirements for the part surface quality. As a result of grinding, a new microrelief is formed on the treated surface in the form of a combination of impact traces of flap wheel abrasive grains and the remained indents of shot blasting. However, the value of the depth of remained shot dents even after grinding is much larger than the values of surface roughness dents formed as a result of the impact of flap wheel grains. Since the indents have a spherical shape with the curvature radius much larger than their depths they have a special effect on the amount of removed metal with the allowance growth. The paper gives an analytical description of material removal from the shot peened surface when grinding with a flap wheel on the basis of the analysis of surface microgeometry.

shot peening, coverage degree, flap wheel grinding, indents, volume of removed material, allowance