Effect of Ce on Structure and Nonmentallic Inclusions of Nb-containing Super Invar

The influence of cerium on the as-forged microstructure and nonmetallic inclusions of Super-Invar alloy Fe-32Ni-4.7Co-0.1Nb was studied systematically by OM,SEM and EDAX.The results show that the addition of trace cerium in Super-Invar alloy doesn't change the phase of the Super-Invar alloy Fe-32Ni-4.7Co-0.1Nb which is still γ-phase,however,the as-forged microstructure is refined.The morphology of sulfide inclusion in Super-Invar alloy turns from string to ellipse or sphere with addition of trace cerium and the shape of sulfide inclusion in Super-Invar alloy is changed.