Effect of free edge on thermal stresses in quenched steel plates

Abstract

A finite–element technique has been used to examine the effect of the edge on the generation of thermal stress in a water–quenched circular plate of a steel of high hardenability. This allows results obtained using an infinite–plate model to be applied to finite bodies, where the stress distribution is influenced by the presence of a free edge. The radial residual stress begins to fall towards zero at a point about one–and–a–half plate thicknesses from the free edge. The variation in the stress in this part of the plate was complex and was accompanied by the development of an axial stress which was compressive up to a point close to the edge, where it became tensile. The variation in the hoop stress resembled that in the radial stress, but tensile values were always obtained at points on the edge. The mean value of the radial and hoop stresses in the edge–affected region was 75% of the stresses formed in the interior of the plate. This provides a suitable conversion factor when finite bodies are involved.MST/5