The influence of surface defects on high-cycle fatigue of engineering materials

An investigation was performed on the influence of surface defects, such as indentor's imprint, etching pits, and nonmetallic inclusions, upon high-cycle fatigue of alloyed steel 20Kh13, carbon steel 20, and titanium alloy VT3-1 in torsion and rotational bending. Defects were initiated on the surface after its polishing, grinding, and surface plastic deformation. The analysis of the results obtained involved the use of the theoretical stress concentration factor values and the magnitudes of residual stresses in the surface layer after different types of surface treatment, as well as residual stresses generated by the introduced defects. A method has been substantiated for predicting the influence of defects on fatigue limit taking into account the defect area.Published in Problemy Prochnosti, No. 1, pp. 5–16, January, 1996.