Abstract: A method for manufacturing a steel plate provided with a layered structure. A method for manufacturing a steel plate includes: i) providing a high carbon steel plate; ii) homogenizing the high carbon steel plate; iii) transforming the high carbon steel plate into an austenitic phase by heating the high carbon steel plate; iv) contacting the high carbon steel plate with an oxidization gas and converting the high carbon steel plate into a steel plate comprising surface layers that are spaced apart from each other and are decarburized to be transformed into a ferritic phase, and a center layer that is located between the surface layers and is not decarburized; and v) cooling the high carbon steel plate and transforming the center layer into a martensitic phase.

Abstract: A method of imparting high strength, high ductility, and high fracture toughness to a refractory metal alloy workpiece includes: (i) subjecting the workpiece to at least one pass that reduces the initial cross-sectional area of said workpiece, (ii) annealing the workpiece subsequent to the at least one pass, and (iii) subjecting the workpiece to a final working step comprising at least one pass conducted at a temperature between ambient and 300.degree. C., the final working step further reducing the cross-sectional area of the workpiece such that the total reduction in the initial cross-sectional area of the workpiece is approximately 40%-75% and the final cold working is 0.30 to 0.75 of the total reduction in cross-sectional area. The resulting article has a tensile yield strength of approximately 170-200 Ksi, a tensile elongation of approximately 12%-17%, and a Charpy 10 mm Smooth Bar impact toughness of approximately 100 ft.-lb. to 240 ft.-lb.