The study of EDM hole-drilling method for measuring residual stress in SKD11 tool steel

This study develops the EDM drilling process to measure the residual stress in high-performance materials, whose stress state is difficult to obtain by a widely used technology called high-speed (HS) hole-drilling method (ASTM Standard E837). SKD11 (JIS) tool steels were prepared in different pre-stressed levels in order to simulate any possible residual stress existing in the workpieces. The experimental results reveal that the stress measurement curves of both EDM conditions, which have the same EDM energy, are parallel with the ideal curve. Therefore the results of EDM hole-drilling method can be positively calibrated by a constant, and it depicts the feasibility of residual stress measurement on materials with high hardness and wear resistance.