Development of a Novel Melt Spinning-Based Processing Route for Oxide Dispersion-Strengthened Steels

Abstract

Melt spinning of an Fe-5Y and Fe-1Y-1Ti (wt pct) alloy produced a relatively uniform spatial distribution of Y and Ti in solid solution and ribbons with consistent yield (>60 pct by weight), fast processing time (< 10 seconds), good scalability (up to > 100 g feedstock material), and repeatability. Heat treatment in the presence of Fe 2 O 3 as an oxygen source (Rhines pack method) at 973 K validated the potential of forming < 20 nm Y-rich oxides in the Fe-5Y ribbons. Pulverized Fe-1Y-1Y ribbons were consolidated to bulk using the field-assisted sintering technique (FAST) incorporating nano-sized Fe 3 O 4 powder as the oxygen source. After FAST at 1273 K, 50 MPa, and 30 minutes, a comparatively high number density of sub-micron Y and/or Ti-rich oxides were developed. Further formation of fine-scale oxides took place during post-FAST annealing, resulting in an approximate 20 pct increase in hardness at temperatures below 573 K, but with a reduced hardening effect above 673 K due to a small fraction of persistent porosity and mechanically weak prior ribbon boundaries that were decorated with Ti-rich oxides.

Research progress on preparation technology of oxide dispersion strengthened steel for nuclear energy

“…To form fine dispersed oxides in ribbons, the environment of melt spinning needs to contain oxygen partial pressure, so oxygen can diffuse into the liquid ribbon to form fine dispersed oxides. Hong et al [66] conducted melt spinning of Fe-1Y-1Ti to produce a uniformly distributed solid solution of Y and Ti. A ODS steel with rich Y oxides of less than 20 nm was obtained by heat treatment at 700 • C under the environment of Fe 2 O 3 as the oxygen source, as shown in figure 12.…”