Potential for Using Yttrium Oxide Powder as a Strengthening Phase for Centrifugal Casting of Corrosion-Resistant Steels

The authors have analyzed the necessity to improve the composition of existing critical structural materials for the purpose of developing metal matrix materials, which combine a highly plastic metal base and high-melting, high-strength, high-modulus fillers. Dispersed yttrium oxide (Y 2 O 3 ) particles are preferred for iron matrix alloys, because of their stability at pyrometallurgical process temperatures and inertness to alloy components. The manufacturing of new materials by addition of dispersed particles into a liquid melt during casting using a centrifugal casting machine to obtain a hollow (pipe) billet is considered. The potential for improving the mechanical and operational properties of metal matrix materials in comparison with the monomaterial is demonstrated. This paper describes the thermodynamic modeling of high-temperature processes in the yttrium oxide–metal matrix (melt) system. The modeling has been carried out using the FactSage software package. A composition corresponding to 12Cr18Ni10Ti (12Kh18N10T) steel was used to model the matrix material. The calculations have been based on the ratio of 1 g of yttrium oxide additive per 100 g of matrix metal melt. It can be concluded based on the modeling results that the added dispersed yttrium oxide powder does not interact with alloy components, does not dissociate, and does not undergo allotropic transformations. The experiments on production of centrifugal castings using yttrium oxide as a strengthening phase with the aim of increasing radiation resistance have been proved to be expedient. The developmental focus of the most effective technology for creating metallic materials based on iron matrix dispersed-hardened with yttrium oxide has been established.