Precipitation hardenable stainless steel

Claim 1

A PRECIPITATION HARDENABLE STAINLESS STEEL CHARACTERIZED BY A GOOD COMBINATION OF STRENGTH AND TOUGHNESS AND CONSISTING ESSENTIALLY OF ABOUT 11% TO 13% CHROMIUM, ABOUT 9% TO ABOUT 11% NICKEL, ABOUT 1.5% TO 3% MOLYBDENUM WITH THE PROVISO THAT THE SUM OF 0.8 TIMES THE CHROMIUM CONTENT PLUS THE NICKEL AND MOLYBDENUM CONTENT IS AT LEAST ABOUT 20% AND NOT MORE THAN ABOUT 23%, AT LEAST ONE METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM AND COLUMBIUM, THE TITANIUM BEING FROM ABOUT 0.1% TO NOT MORE THAN 0.5% AND THE COLUMBIUM BEING FROM 0.1% TO 1%, ABOUT 1% TO 1.6% ALUMINUM WITH THE PROVISO THAT THE SUM OF THE ALUMINUM AND ANY COPRESENT TITANIUM DOES NOT EXCEED 1.9% AND WITH THE FURTHER PROVISO THAT THE RATIO OF NICKEL TO THE SUM OF ALUMINUM AND ANY CO-PRESENT TITANIUM IS AT LEAST 5 TO 1, CARBON IN AN AMOUNT UP TO 0.03%, UP TO 0.2% MANGANESE, UP TO 0.2% SILICON UP TO 0.5% COPPER, UP TO 0.1% BERYLLIUM, UP TANTALUM, UP TO 0.5% COPPER, UP TO 0.1% BERYLLIUM, UP TO 0.01% BORON, UP TO 0.05% ZIRCONIUM AND THE BALANCE ESSENTIALY IRON.