Sintering of maraging steel with phosphorous additions

Abstract

The aim of this study was to develop a steel powder system for rapid tooling applications. The properties required are rapid densification, dimensional precision, high mechanical strength and corrosion resistance. To this end, the densification and microstructural development of a loose packed 200 grade maraging steel powder sintered with ferrophosphorous additions was examined. Liquid initially formed from a reaction of the Fe₃P and carbon, which was a residue of the polymeric binder used to shape the powder compact. This liquid caused a burst of sintering which ceased as the liquid dissipated. On further heating, a phosphorous rich supersolidus liquid appeared at triple points and grain boundaries leading to rapid densification and a sintered density of 98%.