Process for producing stainless steel and alloy thereof

Claim 1

THE PROCESS OF MANUFACTURING A HIGH PURITY IRON ALLOY HAVING A CONTENT, BY WEIGHT, OF LESS THAN ABOUT 0.015% OXYGEN LESS THAN ABOUT 0.006% CARBON AND LESS THAN ABOUT 0.005% NITROGEN, SAID PROCESS COMPRISING THE STEPS OF MELTING IRON IN A VACUUM FURNACE, SAID IRON BEING CONFINED BY A CRUCIBLE PREDOMINATING IN AN OXIDE OF A METAL HAVING A HIGH VAPOR PRESSURE AT THE TEMPERATURE OF THE MOLTEN IRON, ADDING TO SAID IRON AT SOME STAGE IN SAID PROCESS AN AMOUNT OF CARBON IN EXCESS OF THE AMOUNT NEEDED FOR STOICHIOMETRICALLY REACTING WITH THE OXYGEN IN SAID IRON, EVACUATING SAID FURNACE, HEATING SAID IRON AND CARBON TO A TEMPERATURE ON THE ORDER OF ABOUT 1650*C., MAINTAINING SAID TEMPERATURE SUBSTANTIALLY CONSTANT, MEASURING THE RATE OF EVOLUTION OF CARBON MONOXIDE FROM SAID MOLTEN IRON RESULTING FROM REDUCTION OF IRON BY SAID ADDED CARBON, ARRESTING THE REACTION BETWEEN THE MOLTEN IRON AND THE CRUCIBLE AT SOME POINT BETWEEN THE TIME WHEN THE CARBON MONOXIDE EVOLUTION RATE FALLS TO ABOUT 20 MICRON CUBIC FEET PER MINUTE PER POUND OF IRON AND BEFORE THE CARBON MONOXIDE EVOLUTION RATE FALLS TO ABOUT 4 MICRON CUBIC FEET PERR MINUTE PER POUND OF IRON, AND ADDING AT LEAST ONE ALLOYING ELEMENT TO SAID DEOXODIZED IRON TO FORM A HIGH PURITY IRON ALLOY CONTAINING 16% TO 26% CHROMIUM AND 6% TO 22% NICKEL.