Slurry erosion, sliding wear and corrosion behavior of martensitic stainless steel composites reinforced in-situ with NbC particles

Abstract

AISI 440B martensitic stainless steels reinforced with up to 15 vol% NbC particles were successfully cast using a vacuum induction furnace. Energy dispersive x-ray spectroscopy, scanning electron microscopy and electron backscatter diffraction techniques revealed that NbC additions led to a slight decrease in the matrix solid solution Cr content, which was found to have a minor impact on uniform corrosion resistance. An ISO 21988 grade Cr27 martensitic eutectic white cast iron was used to benchmark the wear performance of the composites. Hardness, sliding wear tests, and erosion wear tests against a garnet slurry, showed that the composites could either match or surpass the cast iron despite having a lower total volume fraction of carbide phases. These results show that the proposed martensitic stainless steel composites have immense potential in high wear applications that require some degree of corrosion resistance, such as in the mining and mineral processing industry.