20Cr25NiNbRE austenitic stainless steel, and preparation method and application thereof
By introducing cerium microalloying and multi-stage hot working processes into 20Cr25NiNb austenitic stainless steel, the hot brittleness and grain boundary problems of existing materials have been solved, and the high-temperature ductility and service stability have been improved, making it suitable for ultra-supercritical boilers and high-temperature nuclear power reactor internals.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INST OF METAL RESEARCH - CHINESE ACAD OF SCI
- Filing Date
- 2026-06-16
- Publication Date
- 2026-07-17
AI Technical Summary
Existing 20Cr25NiNb austenitic stainless steel has problems such as significant hot brittleness, continuous precipitation at grain boundaries, high Cr depletion tendency at grain boundaries, and insufficient processing plasticity reserve during high-temperature service and hot working, which leads to increased risk of forging cracking and unstable mechanical properties.
By introducing trace amounts of cerium (Ce) for microalloying, combined with ultra-high purity smelting and vacuum pressurized nitrogen alloying technology, the content of harmful impurities is controlled. A multi-stage hot processing process is adopted, including ingot homogenization, three upsetting and three drawing deformation, intermediate annealing and solution treatment, to achieve inclusion refinement, microstructure homogenization and grain refinement.
It significantly improves the high-temperature thermal ductility and microstructure stability of the material, enhances its high-temperature service reliability and hot processing safety, reduces grain boundary embrittlement tendency, and improves its high-temperature ductility and resistance to hot cracking.
Smart Images
Figure CN122406110A_ABST