PIII-nitriding of boron implantated stainless steel

In this report we present results of nitrogen PIII into 50 keV boron implanted austenitic stainless steel at 400°C and 40 kV. A surface layer of 90 nm consisting of expanded austenite (γN1 — lattice expansion 6.5%) and ferrite as well as containing 30 at.% B was found. This layer was followed by another one containing expanded austenite with reduced expansion (γN2 — lattice expansion 2.5%) before the base material was reached. Auger electron spectroscopy (AES) and X-ray diffraction (XRD) at various angles of incidence were used to obtain these results. After annealing at 400°C for 5 h further nitrogen diffusion, but no boron diffusion was observed.