Surface treatment of steel by short pulsed injection of high-power ion beam

A hydrogen-high power and short pulsed ion beam (PPIB) with ion energy of 160 keV, ion beam current density of 500 A/cm2 and pulse duration (FWHM) of 65 ns was injected into a high-speed tool steel (SKH51), producing an austenitic phase in nm-sized polycrystals on the surface layer of target. The average crystal size in the austenitic phase was estimated to be 40 nm, which is 1/170 of crystal size before the PPIB injection. The heat affected depth is estimated to be approximately 1.0 μm from the surface that is in good agreement with the ion range calculated by TRIM code.