Microstructure and Corrosive Wear Property of Super High Chromium Cast Iron (SHCCI)

To increase the wear resistance of components in slurry pump suffering from serious corrosive abrasion, new super high chromium cast iron (SHCCI) which contains 37wt.% chromium approximately and different carbon content were developed based on the high chromium cast iron with 26wt.% Cr (Cr26). The microstructure of SHCCI was investigated by SEM and XRD. The hardness and impact toughness of SHCCI was tested, and the corrosive wear property of SHCCI was also researched using MCF-30 type erosion abrasion tester under H3PO4 medium condition. The results show that the microstructure of SHCCI is composed of carbide of M7C3+M23C6, martensite and retained austenite. With the increase of carbon content, the hardness of SHCCI first increases and then decreases, the toughness increases, and the corrosive wear property decreases. The relative wear resistance of SHCCI is obviously superior to that of Cr26 cast iron, and the maximal relative wear resistance of SHCCI is three times higher than that of Cr26 cast iron.