Martensitic low alloy plate steel

Claim 1

A MARTENSITIC LOW ALLOY STEEL PARTICULARLY ADAPTED FOR USE AS A STEEL PLATE IN SECTION SIZES UP TO AT LEAST 1 INCH IN THICKNESS AND CHARACTERIZED WHEN QHENCHED AND TEMPERED AT TEMPERATURES OF AT LEAST 1100*F. BY A YIELD STRENGTH (0.2% OFFSET) OF OVER 90,000 P.S.I., A TENSILE STRENGTH OVER 100,000 P.S.I., A YEILD TO TENSILE STRENGTH RATIO OF AT LEAST 0.8, A CHARPY V-NOTCH IMPACT VALUE OF AT LEAST 40FT.LBS. AT ROOM TEMPERATURE AND 15FT.-LBS. AT TEMPERATURES OF AT LEAST AS LOW AS -150F., AND GOOD DUCTILITY AND WELDABILITY, SAID ALLOY STEEL CONSISTING ESSENTIALLY OF ABOUT 0.15% TO ABUT 0.22% CARBON, ABOUT 0.65% TO ABOUT 1% MANGANESE, ABOUT 0.2% TO ABOUT 0.35% SILICON, ABOUT 0.7% TO ABOUT 1% NICKEL, ABOUT 0.2% TO ABOUT 0.35% CHROMIUM, ABOUT 0.15% TO ABOUT 0.3% MOLYBDENUM, ABOUT 0.02% TO ABOUT 0.06% ALUMINUM, ABOUT 0.0005% TO ABOUT 0.004% BORON, AND THE BALANCE ESSENTIALLY IRON.