Abstract: A steel plate product, and the method for producing same, wherein the plate, in thicknesses up to 4.0 inches, is characterized in the as-rolled condition by high strength, a uniform fine grain size, and good toughness at low temperatures. The processing techniques include among other features a modified controlled rolling practice.

Abstract: This invention is directed to a thermal-mechanical process, and to the product thereof, for treating carbon or low alloy steels to improve their strength and toughness. The process is characterized by the steps of austenitizing a carbon or low alloy steel workpiece, preferably in the form of a slab, reducing said slab at a temperature above about 1900.degree. F. (1038.degree. C.) to a thickness in the range of 2 to 4 inches (5.1 to 10.2 cm), controlled quenching to effect thermal equilibration until a surface-to-center thermal gradient within a temperature range of 50.degree. to 150.degree. F. (28.degree. to 83.degree. C.) is reached, and initiating working such control quenched workpiece at an average temperature within the range of 1450.degree. to 1750.degree. F. (788.degree. to 954.degree. C.). The reduced steel product, having been treated in accordance with said thermal-mechanical process to yield a rolled steel plate having a thickness between about 0.5 to 1.25 inches (1.3 to 3.