超304H奥氏体钢在700°C的长期爬行过程中的微结构演变
Jiale Zhang1, Zhengfei Hu1, Ziyi Gao1
1School of Materials Science and Engineering, Tongji University, Shanghai 202409, China.
Materials (Basel, Switzerland)
|May 7, 2025
概括
超304H奥氏体钢中的高温爬行会导致各种沉物,增强强度. 然而,在高应力下,快速的西格玛相沉可以削弱谷物边界,而MX沉提供长期稳定性.
科学领域:
- 材料科学 材料科学 材料科学
- 金工业是金工业的一个方面.
- 物理化学 物理化学
背景情况:
- 超304H奥氏体钢对于高温应用至关重要.
- 了解爬行行为对于材料的寿命和性能至关重要.
- 在压力下微观结构的进化决定了机械性能.
研究的目的:
- 为了研究超304H奥氏体钢在700°C的爬行行为.
- 为了确定在高温爬行过程中沉的阶段.
- 为了将沉物形成与应力水平及其对机械强度的影响相关联.
主要方法:
- 在不同压力条件下,在700°C的温度下进行爬行测试.
- 使用光学显微镜 (OM),扫描电子显微镜 (SEM) 和传输电子显微镜 (TEM) 的微结构特征.
主要成果:
- 高温爬行诱导了M23C6,二级MX碳化物, σ阶段,丰富阶段和Z阶段的沉.
- 细沉物通常会增强矩阵和粒度边界强度.
- 沉序列因应应力而变化;在高应力下快速 σ 阶段形成会降低谷物边界强度.
- 在低应力下分散的MX沉物促进了微观结构的稳定性和爬行强度.
- 谷物边界强度的下降与低角度谷物边界变化有关,而不仅仅是空洞.
结论:
- 沉的类型和分布显著影响Super304H钢的抗性.
- 应力水平是控制沉物演变和随后的机械性质的关键因素.
- 微观结构的稳定性和长期的爬行强度可以通过受控的沉物形成来实现,特别是MX类型.
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