High Strength Low Alloy Steel and Method of Manufacturing

摘要

The present invention relates to a wrought, quenched and tempered, fine-grained, with deep hardenability, high strength and low alloy steel having a sum of the alloying elements: nickel, molybdenum, tungsten, vanadium, titanium, and niobium in weight percentage of 1.60% maximum in the first embodiment; vanadium, titanium, and niobium in weight percentage of 0.40% maximum in the second embodiment; titanium and niobium in weight percentage of 0.10% in the third embodiment. The air melted and hot forged steel of the first embodiment has hardness of HRC 55, an ultimate tensile strength of 300 ksi, a yield strength of 257 ksi, a total elongation of 9%, a reduction of area of 32%, and Charpy v-notch impact toughness energy of 15 ft-lb after normalizing, gas quenching, and tempering at 450° F.

主权项

1. A quenched and tempered, fine-grained, with deep hardenability, high strength and low alloy steel comprising in weight percent about 0.18% to 0.55% carbon, about 0.0% to 0.05% nitrogen, about 2.0% maximum manganese, about 1.5% maximum copper, about 1.0% maximum nickel, about 3.0% maximum chromium, one or two elements of molybdenum and tungsten, wherein sum of molybdenum and tungsten about 0.20% maximum, about 0.30% maximum vanadium, one or two elements of titanium and niobium, wherein sum of titanium and niobium about 0.10% maximum, about 2.0% maximum silicon, about 0.0% to 0.20% aluminum, about 0.0% to 0.02% calcium, about 0.035% maximum phosphorus, about 0.04% maximum sulfur, and balance iron and incidental impurities, and said steel having ideal diameter about 5 inch to 21 inch.