Using the Radial-Shear Rolling Method for Casted Zirconium Alloy Ingot Structure Improvement

Area of Science:

• Materials Science
• Metallurgy
• Nuclear Engineering

Background:

• Nuclear industry requires advanced alloys with improved composition and processing.
• Zirconium-niobium (Zr-1%Nb) alloys are critical for nuclear applications.
• Traditional processing methods for zirconium alloys can be lengthy and complex.

Purpose of the Study:

• To investigate the application of radial-shear rolling (RSR) on a Zr-1%Nb alloy ingot.
• To evaluate the effectiveness of RSR in refining the microstructure and improving properties.
• To assess the scientific interest and applicability of RSR for zirconium ingot processing.

Main Methods:

• Vacuum induction melting (VIM) to produce a 30 mm diameter Zr-1%Nb alloy ingot.
• Two-stage radial-shear rolling (RSR) process.
• Initial rolling at 800 °C to 20 mm diameter to refine cast structure.
• Second rolling stage at 530 °C to 13 mm diameter to achieve ultrafine-grained structure.

Main Results:

• Successful application of RSR to a Zr-1%Nb alloy ingot.
• Elimination of defects and refinement of the cast structure in the first stage.
• Formation of an ultrafine-grained structure after the second rolling stage.
• Demonstration of combined structural refinement and defect healing within fewer cycles.

Conclusions:

• Radial-shear rolling is a viable and efficient method for processing Zr-1%Nb alloy for nuclear applications.
• RSR offers a potential reduction in traditional processing steps.
• The refined microstructure and improved properties make the material suitable for nuclear reactor components.
• This study validates the scientific interest in applying RSR to zirconium ingots.