Analysis of The Influence of Alloying on the Performance Properties of Cast Iron Grades 280Cr29Ni and 330Cr17 with the Purpose of Increasing their Quality
Abstract
The hardness and microstructure of the High chromium cast irons (HCCIs) grades 280Cr29Ni and 330Cr17, which are predominantly utilized in the production of components for mining and metallurgical equipment subject to wear conditions, have been thoroughly investigated. A thermodynamic analysis of multicomponent Fe-2.6C-Cr-alloying elements (a.e.), was conducted to investigate the crystallization processes of alloys, the development of their metallic matrix structure, and the formation and transformation of carbide phases. Based on the analysis, the optimal quantity and ratio of alloying elements (Cr, Mn, Si, and Ti) in the Fe-2.6C-Cr-a.e., system required for the formation of a metallic matrix and carbide phases that maximize the hardness of the alloy were determined. State diagrams were constructed for ternary, quaternary, and multicomponent systems, including Fe-CCr, Fe-C-Ni, Fe-C-Mn, Fe-C-V, Fe-C-Mo, Fe-C-Co, Fe-C-Cr-Ni, Fe-C-Cr-Mn, and Fe-C-Cr-Mn. These diagrams, along with their isothermal (at 200 °C) and polythermal sections, enriched the theory of phase diagrams, which form the foundation of HCCIs. The analysis covered a range of chromium concentrations (16-34%), nickel (0.4-3%), manganese (0.4-2%), carbon (2.4-4%), silicon (0.3-2%), titanium (0.4-5%), molybdenum (0.2-3%), and vanadium (0.01-2%). Phase equilibrium points were determined, encompassing an alloyed solid solution based on iron, multicomponent carbides, and a mixture of phases consisting of a solid solution of iron and carbides. An economical grade of HCCIs has been developed with the following composition: carbon 3.2-3.4%, manganese 0.4-0.6%, chromium 16-18%, silicon 0.4-0.6%, nickel 0.4-0.6%, molybdenum up to 0.4-0.5%, with the balance being iron