Addition agent and method for introducing magnesium into cast iron

Claim 1

AN IMPROVED PROGESS FOR PRODUCING MAGNESIUM-CONTAINING CAST IRON CONTAINING COMPACTED GRAPHITE WHICH COMPRISES ESTABLISHING A BATH OF MOLTEN CAST IRON OF SUCH A COMPOSITION THAT IF CAST AT LEAST AFTER INOCULATION IT WOULD BE A GRAY CAST IRON; INCORPORATING AT LEAST A SMALL BUT EFFECTIVE AMOUNT OF MAGNESIUM IN SAID BATH BY TREATING SAID MOLTEN BATH WITH ABOUT 1% TO 8% OF AN ADDITION AGENT COMPRISED OF CALCIUM CYANAMIDE AND SUCH A PROPORTION OF A REACTIVE INGREDIENT CONTAINING AT LEAST 10% MAGNESIUM AND UP TO A TOTAL OF 90% OF METAL FROM THE GROUP CONSISTING OF NICKEL, COPPER AND SILICON THAT THE WEIGHT RATIO OF CALCIUM CYANAMIDE TO SAID REACTIVE INGREDIENT IN SAID ADDITION AGENT IS BETWEEN ABOUT 0.5 TO 1 AND ABOUT 6 TO 1; AND CASTING A MAGNESIUM-CONTAINING CASTING FROM METAL OF SAID BATH IN AN INOCULATED CONDITION TO OBTAIN THEREIN UNCOMBINED CARBON AS COMPACTED GRAPHITE.