Effects of triaxial rolling on the microstructure and installation characteristics of reactor pressure vessel studs
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View abstract on PubMed
Summary
This summary is machine-generated.Triaxial rolling of reactor pressure vessel (RPV) studs refines thread root microstructure, creating ultrafine grains and strong textures. This leads to a 6% reduction in residual elongation during installation, enhancing RPV stud performance.
Area Of Science
- Materials Science
- Mechanical Engineering
- Nuclear Engineering
Background
- Reactor pressure vessel (RPV) studs are critical for sealing nuclear reactors under extreme conditions.
- The integrity of RPV stud threads directly impacts reactor safety and operational efficiency.
Purpose Of The Study
- To investigate the effects of triaxial rolling on the microstructure and texture of RPV stud external threads.
- To evaluate the impact of triaxial rolling on the installation characteristics of RPV studs.
Main Methods
- Finite element analysis coupled with viscoplastic self-consistent simulations for texture evolution prediction.
- Scanning electron microscopy and electron back-scattered diffraction for microstructure characterization.
- Installation and pretightening tests to assess stud performance.
Main Results
- Triaxial rolling induced dynamic recrystallization, forming ultrafine tempered sorbite grains and high-angle grain boundaries (47%) at the thread root.
- Strong {111} <110> and {111} <112> textures were observed in the rolled thread root material.
- Rolled RPV stud parts exhibited a 6% reduction in residual elongation compared to turned parts under identical loading.
Conclusions
- Triaxial rolling creates a gradient microstructure in RPV stud thread roots, optimizing their properties.
- The refined microstructure and texture enhance stud installation characteristics, improving sealing performance and reliability.
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