Abstract: A vanadium-nitrogen microalloyed steel is continuously hot rolled to C-shaped sections that meet property requirements for side rails of truck frames with no heat treatment. Sections with different thicknesses of the web and flange regions can also be prepared by the same processing. The composition of the steel is from about 0.16 to about 0.20 percent carbon, from about 1.2 to about 2.0 percent manganese, from about 0.45 to about 0.55 percent silicon, from about 0.10 to about 0.30 percent vanadium, from about 0.001 to about 0.030 percent aluminum, from about 0.010 to about 0.027 percent nitrogen, less than about 0.030 percent phosphorus, less than about 0.030 percent sulfur, balance iron totalling 100 percent, with all percentages by weight. Variations of this steel containing either from about 0.01 to about 0.02 percent titanium or 0.04 to about 0.07 percent aluminum are also permissible.

Abstract: A microalloyed, fully killed steel has a composition, in weight percent, of from about 0.20 to about 0.45 percent carbon, from about 0.90 to about 1.70 percent manganese, from about 0.10 to about 0.35 percent silicon, from about 0.01 to about 0.04 percent aluminum, from about 0.05 to about 0.20 percent vanadium, from about 0.008 to about 0.024 percent nitrogen, balance iron. The steel is particularly useful when hot rolled to a railway joint bar section, and air cooled. The resulting joint bar meets AREA specifications in the as-rolled condition, without the need for a reheat and oil quench heat treatment after rolling.