INFLUENCE OF MINOR ADDITIONS OF NITROGEN AND TITANIUM ON THE CARBIDE MORPHOLOGY AND TRANSFORMATIONS IN CHROMIUM CAST IRONS

摘要

Titanium and nitrogen additions (as nitrided manganese or nitrided chromium) to 12 percent chromium cast irons partially refine the eutectic carbide morphology.Plain 12 percent Cr cast irons do not transform to martensite on forced air draft quenching from 950 deg C. Nitrogenated 12 percent chromium cast irons having approximately 2.5 percent Mn are air hardenable.A secondary hardening effect associated with precipitation of Ti_2N or AlN has been observed in 12 percent chromium cast irons containing N + Ti or N + Al respectively during tempering of as cast or as quenched samples at 600 deg C.