What effects does residual stress induced by metal cutting h

What effects does residual stress induced by metal cutting have on mechanical component

Solution

Residual stress phenomenon is dominant in machining processes where cutting tool and work material are in c0ntact with each other and as a result of elastic-plastic deformation of the material and heat treatment, such stresses are found to have a very significant effect on the fatigue life of components. Those stresses that exist in a machine part without external loading being present, these residual stresses are “locked into” the component in the absence of external loadingand represent a datum stress over which the service load stresses are subsequently superimposed.

Residual stress can be tensile or compressive and the stressed layer can have multiple depths, depending upon the cutting conditions, work material, cutting tool geometry and contact conditions at the tool/chip and tool/work piece interfaces. The compressive residual stress close to the surface of the work piece is high and decreases as the depth increases. At certain depth the residual stress becomes negligible and further increase in the depth results into tensile residual stress. Compressive residual stresses generally improve component performance and life because they promote service stresses and prevent crack nucleation. On the other hand, tensile residual stresses tend to increase service stresses which lead to premature failure of components [