Improvement of physical and chemical properties of steel implanted with Cr+, Ti+, Si+ ions

Abstract

Low carbon steels (St3, St45) and a chromium doped steel (St40Cr) were implanted with 15-20 keV T i+, Cr+ or co-implanted with (Ti + Si)+, (Cr + Si)+ ions to a dose of 8 X 1016 ions cm-2 . The composition of the surface region was examined by RBS and nuclear resonance scattering techniques. These analyses showed a relationship between the implanted ion doses and the oxygen concentration in the layer. The hardness of the implanted surface grew with increasing ion dose. This effect is associated with radiation damage and chemical compounds created in the surface regions of the ion-implanted steels. The corrosion properties of the steels were studied and the first results from electrochemical analysis of corrosion behaviour of samples in de-aerated borate buffer solution (pH = 6.5) are discussed.