Analysis of residual stress in subsurface layers after precision hard machining of forging tools

Abstract

This paper is focused on analysis of residual stress of functional surfaces and subsurface layers created by precision technologies of hard machining for progressive constructional materials of forging tools. Methods of experiments are oriented on monitoring of residual stress in surface which is created by hard turning (roughing and finishing operations). Subsequently these surfaces were etched in thin layers by electro-chemical polishing. The residual stress was monitored in each etched layer. The measuring was executed by portable X-ray diffractometer for detection of residual stress and structural phases. The results significantly indicate rise and distribution of residual stress in surface and subsurface layers and their impact on functional properties of surface integrity.

Effect of Lubrication and Forging Load on Surface Roughness, Residual Stress, and Deformation of Cold Forging Tools

“…The residual stresses that were generated by tool production and external stresses induced by the forming process have a major effect on tool life in cold forging [18]. Czan et al [19] analyzed the residual stress in subsurface layers after the precision hard machining of forging tools by the X-ray diffraction method, and the residual stress had a compressive character. Furthermore, Merklein et al [1] studied the influence of the machining process on residual stresses in the surface of cemented carbides, which is a commonly used material for die inserts in the forging tools.…”