Series of carbon steels with various contents of carbon were irradiated with high intensity (5–6Jcm−2), short (μs range) nitrogen and argon plasma pulses. In all samples the near surface layer of the thickness in μm range was melted. The paper reports the results of investigation of changes induced by such treatment. The identified phases, profiles of retained nitrogen concentration, microhardness and wear resistance of the modified layer are presented and discussed.