Influence of Vanadium on Carbide Deposition in the Working Layer of ICDP Iron Rollers

—The influence of vanadium on the microstructure, carbide deposition, and hardness of the chromonickel indefinite iron alloyed with ferrovanadium in the working layer of rollers is investigated. The microstructure of iron alloyed with nonnitrided ferrovanadium consists of primary dendrites; ledeburite; a small quantity of graphite; complex carbides MeC and carboborides Me(C, B) containing niobium, titanium, vanadium and chromium; and also chromium carbides of plate or needle morphology. In samples alloyed with nitrided ferrovanadium, the complex carbonitrides Me(C, N) are also seen. With increase in vanadium content, the proportion of these particles increases from 0.17 to 0.9% for samples alloyed with nonnitrided ferrovanadium and from 0.45 to 0.9% for samples alloyed with nitrided ferrovanadium. Their mean area varies from 1.5 to 2 μm2 and from 1.4 to 1.8 μm2, respectively. In iron alloyed with nitrided ferrovanadium, the maximum hardness (770 HV at a vanadium concentration of 0.4%) is greater than in samples alloyed with nonnitrided ferrovanadium (710 HV at a vanadium concentration of 0.3%).