Enhanced Performance of Austenitic Oxide Dispersion-Strengthened 316L Steel: A Study on Y2O3 Reinforcement and Corrosion Behaviour

<p>This study explores the mechanical and corrosion properties of yttria-reinforced<br />316L stainless steel. Powder precursor materials were prepared using mechanical alloying.<br />Varying yttria (Y2 O3 ) contents (1, 3, and 5 wt%) were used to assess its impact on the<br />steel’s properties. X-ray diffraction and scanning electron microscopy confirmed the<br />successful dispersion of Y2 O3 within the matrix, with the formation of chromium carbides<br />during spark plasma sintering (SPS). The mechanical properties, including hardness and<br />compressive yield strength, improved with increasing Y2 O3 contents, with the highest<br />strength observed in the 316L-5Y2 O3 sample. However, corrosion resistance decreased with<br />higher yttria concentrations. The 3 wt% Y2 O3 sample exhibited the highest corrosion rate<br />due to localized corrosion in areas enriched with oxide particles and chromium carbides.<br />Electrochemical testing revealed that carbide formation and Cr-depleted regions from SPS<br />processing contributed to the corrosion behaviour. These findings suggest that while yttria<br />reinforcement enhances mechanical strength, optimizing the Y2 O3 content and processing<br />methods is crucial to balance both mechanical and corrosion performance in ODS 316L<br />stainless steel.</p>

本研究针对氧化钇（yttria）增强型316L不锈钢的力学性能与耐腐蚀性能开展系统探索。研究采用机械合金化工艺制备粉末前驱体材料，设置1%、3%及5%三种质量分数的氧化钇（Y₂O₃）添加量，以评估其对不锈钢性能的影响。通过X射线衍射（X-ray diffraction）与扫描电子显微镜（scanning electron microscopy）表征，证实Y₂O₃已成功弥散分布于基体中，且在放电等离子烧结（spark plasma sintering, SPS）过程中生成了碳化铬。随着Y₂O₃添加量提升，材料的硬度与压缩屈服强度等力学性能均得到改善，其中316L-5Y₂O₃试样的强度达到峰值。然而，随着氧化钇添加浓度升高，材料的耐腐蚀性能却有所下降。3%质量分数Y₂O₃试样的腐蚀速率最高，这源于其氧化物颗粒与碳化铬富集区域发生的局部腐蚀。电化学测试结果表明，SPS工艺过程中生成的碳化铬以及铬贫化区，是影响材料腐蚀行为的核心因素。本研究结果显示，尽管氧化钇增强可有效提升材料的力学强度，但在氧化弥散强化（oxide dispersion strengthened, ODS）316L不锈钢中，优化Y₂O₃添加量与制备工艺，对平衡材料的力学性能与耐腐蚀性能而言至关重要。