Patent ID: 8906173

Claim:
A method of making a high-strength steel elongated truck frame rail comprising providing high-strength steel having a tensile strength of at least about 120,000 psi and a yield strength of at least about 90,000 psi, wherein the high-strength steel comprises, by weight percent: carbon, about 0.30% to about 0.65%, manganese, about 0.30% to about 2.5%, at least one of the group consisting of aluminum, niobium, titanium, and vanadium, and mixtures thereof, about 0.03% to about 0.35%, and iron, balance, hot-rolling the high-strength steel to provide a truck frame rail having a uniform cross-sectional C-shaped configuration completely over the truck frame rail length, said uniform C-shaped cross-sectional configuration consisting of a web portion with upper and lower opposed flange portions each having an average thickness and extending at about a 90° angle from opposite ends of the web portion, each said upper and lower flange portions intersect the web portion to form a corner having inner and outer radii, said web portion having an average thickness less than the average thicknesses of said upper and lower flange portions, said web portion thickness providing weight savings in said truck frame rail with essentially no strength compromise uniformly along the truck frame rail length as shown by the calculation for comparative section modulus (ΔSM) of said truck frame rail when compared to a baseline frame rail with a web portion and extending flanges having the same thickness.