Effects of Primary Oxide and Oxide-Nitride Particles on the Solidification Structure in a Fe-20 mass%Cr Alloy Deoxidised with Ti and M (M = Zr or Ce)

Abstract

The ratio of equiaxed grains on a cross section and the size of equiaxed grains in a Fe-20 mass% Cr alloy deoxidised with Ti/M (M = Zr or Ce) were studied as function of nitrogen content and particle characteristics such as size distribution, morphology and composition. Fe-20 mass% Cr alloys were melted at 1600°C, deoxidised, and cooled to 1400°C followed by water quenching. Thereafter, the particles were separated from the matrix using electrolytic extraction using a 10%AA electrolyte and collected on a film-filter surface. The inclusion characteristics were determined using SEM. It was found that the number of particles increases with an increased N content. Furthermore, that the solidification structure was clearly affected by the number of primary oxide and oxide-nitride particles in the Ti/Zr deoxidation experiments. However, a similar effect could not be detected in the Ti/Ce deoxidation experiments.