A felületelőkészítés hatása a felületi réteg maradó feszültségi állapotára hidegalakító szerszámacélokon

Abstract

In order to increase the wear resistance and service life of tool steels, we often use ceramic coatings. The performance of these coatings is determined not only by their properties, but also significantly by the characteristics of the surface- and near-surface layer, including their residual stress state. In this paper we investigated the residual stresses developing during grinding, polishing and glass bead blusting in the surface layer of an X153CrMoV12 high-alloy cold forming tool steel, that is intended to be coated by mono- and multilayer superhard DLC coatings. It has been found that each surface treat ment process can result in extremely different stress states, with predominantly tensile stresses after grinding, typically low compressive stresses after polishing, and compressive residual stresses one order of magnitude higher than for polishing as a result of glass bead blasting. Based on the literature, we found that these residual stresses can be greatly modified by changing the processing conditions and technological parameters, emphasizing that in addition to the residual stresses, several other influencing factors must be taken into account when designing the surface quality of the substrate under the ceramic coatings.