Abstract
The functional performance of a ground product depends primarily on two factors: the surface geometry and the physical properties of the ground surface. Surface and subsurface changes in hardened En 24 steel have been examined after dry grinding under different operating conditions. Using the optimized dressing parameters from a separate study, the effect of downfeed, wheel hardness, and grit size have been investigated. The assessment of the surface integrity has been made by considering ground surface quality, microstructural alterations, formation of grinding cracks, and microhardness changes at and below the ground surface. Experimentally measured specific energy consumption during the grinding operation has been used to calculate the instantaneous surface and subsurface temperature at the grinding zone. With a knowledge of this temperature distribution, it has been possible to explain the observed changes in terms of the heat flow mode and tempering characteristics of En 24 steel. The results indicate the formation of a number of microstructural zones, substantial changes in microhardness values, and the development of grinding cracks in ground samples. Irrespective of grit size, J grade wheels have been found to produce surfaces that give optimum surface integrity data. However, H-grade wheels revealed no surface cracks at any downfeed.
MST/368
Get full access to this article
View all access options for this article.