A steel piston ring and a steel cylinder liner are described which comprise as the main body a steel composition which has good nitridability. The steel composition consists of the following elements: 0-0.5 weight % B, 0.5-1.2 weight % C, 4.0-20.0 weight % Cr, 0-2.0 weight % Cu, 45.30-91.25 weight % Fe, 0.1-3.0 weight % Mn, 0.1-3.0 weight % Mo, 0-0.05 weight % Nb, 2.0-12.0 weight % Ni, 0-0.1 weight % P, 0-0.05 weight % Pb, 0-0.05 weight % S, 2.0-10.0 weight % Si, 0-0.05 weight % Sn, 0.05-2.0 weight % V, 0-0.2 weight % Ti and 0-0.5 weight % W. The steel piston ring and the steel cylinder liner can be manufactured in a casting process using the machinery and technology employed for the manufacture of cast iron parts.