Microstructure and Wear Properties of Vanadium Containing High Chromium White Cast Irons

摘要

High chromium white cast irons are commonly used where abrasion resistance is needed. Several investigators have reported the low stress abrasion resistance of white cast irons containing a various amount of carbide using rubber wheel abrasion tester (RWAT) with SiO_2 and Al_CO_3 abrasives. In this study the role of MC type carbides with high hardness as well as M_7C_3 type carbides in improving abrasive war resistance was investigated. The weight percent of V was fixed as 5 wt. percent. However, the volume fraction of MC type carbide was decreased with increasing the volume fraction of primary (Cr, Fe, V)_7C_3 type carbides due to the increase of higher Cr and C alloying content in hyper high chromium white cast irons. As a result, the specimen with many primary M_7C_3 type carbides and the lowest volume fraction of MC type carbide had the best abrasion wear resistance against SiO_2 abrasive, but it was not effective for abrasive wear resistance against Al_CO_3 abrasives.