FATIGUE STRENGTH IMPROVEMENT OF HIGH STRENGTH MARTENSITIC STAINLESS STEEL BY DYNAMIC ION MIXING PROCESS

摘要

TiN films of 0.2μm thick were formed on a high strength martensitic stainless steel of 1mm thick by dynamic ion mixing process to investigate the effect of the films on the fatigue strength of the steel. Characteristics of the films were evaluated from X-ray photoelectron spectro-scopy and X-ray diffraction together with hardness and residual stress measurements. Results of four-point bending fatigue tests indicated that, when appropriate process parameters were applied, the fatigue strength could be raised. And the increase in the fatigue strength was correlated well with the surface micro-hardness and the residual stress of the films.