PRODUCTION EXPERIENCE WITH THE BORON MODIFIED NICKEL HIGH-TEMPERATURE CASTING ALLOYS

A family of superalloys called the BC alloys have been produced where the carbon level is held to less than 0. 03% and boron is raised from typically 0. 015% to about 0. 1%. The microstructure and stability of the BC alloys, because of these chemical changes, are strikingly different from the conventional nickel-base superalloys. It is shown that the excellent properties and characteristics of the BC alloys can be reproduced in large-scale production melts of the alloys. Experience to date indicates that re-melted scrap (i. e. revert) material suffers no reduction in these advantages.