Abstract
Compositions of type 304 austenitic stainless steels were modified with the addition of boron, cerium and titanium. The addition of cerium and titanium removed mobile sulfur almost completely by formation of sulfides (Ce2O2S2 and Ti4C2S2). Boron nitride precipitated during creep tests on creep cavity surfaces in sulfur-free samples. Auger electron spectroscopic analyses of the chemistry of creep cavity surfaces, exposed by breaking the creep exposed specimens at liquid nitrogen temperature under impact loading, revealed the precipitation of boron nitride on creep cavity surface. The boron nitride suppressed creep cavity growth and provided the steel with higher rupture strength and higher rupture ductility.
