Nitride-bearing low carbon ductile steels

Claim 1

A NITRIDE-BEARING DUCTILE STEEL CONSISTING OF LESS THAN .035% CARBON, LESS THAN 0.035% OF EACH OF SULPHUR AND PHOSPHOROUS, LESS THAN 1% OF MANGANESE, LESS THAN 0.5% OF SILICON, FROM 0.015 TO 0.090% OF AT LEAST ONE OF THE SUBSTANCES SELECTED FROM THE GROUP CONSISTING OF BERYLLIUM NITRIDE, COLUMBIUM NITRIDE, A COMBINATION OF ALUMINUM NITRIDE AND BERYLLIUM NITRIDE, A COMBINATION OF ALUMINUM NITRIDE AND COLUBIUM NITRIDE, A COMBINATION OF BERYLLUM NITRIDE AND COLUMBIUM NITRIDE, AND A COMBINATION OF ALUMINUM NITRIDE, BERYLLIUM NITRIDE AND COLUMBIUM NITRIDE; FROM 0.01 TO 0.10% OF AT LEAST ONE OF THE NITRIDES SELECTED FROM THE GROUP CONSISTING OF TITANIUM NITRIDE AND ZIRCONIUM NITRIDE, THE REMAINDER BEING SUBSTANTIALLY ALL IRON WITH INCIDENTAL IMPURITIES, A PORTION OF THE NITRIDES BEING COMBINED IN THE MATRIX OF THE STELL, THE REMAINDER OF THE NITRIDES EXISTING AS FREE NITIDE IN THE FORM OF FINE PARTICLES DISPERSEDLY PRECIPITATED IN THE GRAINS AND ON THE GRAIN BOUNDARIES OF THE STEEL TO THEREBY PROVIDE IMPROVED MECHANICAL PROPERTIES OF THE STEEL.