在梯度结构钢中对循环爬行具有优越的阻力
Qingsong Pan1, Kunqing Ding2, Song Guo1,3
1Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, P.R. China.
概括
研究人员研制出高强度的奥氏体不钢, 由于异位细胞的独特梯度层次和微观结构的精细化,这种材料具有显著较低的循环爬行率.
科学领域:
- 材料科学
- 机械工程
- 金属工程
背景情况:
- 循环爬行是结构材料的关键疲劳失效机制.
- 与平均应力不对称的应力循环导致累积的塑料应力,导致材料过早失效.
- 在材料工程中,提高杆阻力是一个重大挑战.
研究的目的:
- 通过一种新型的高强度奥氏体不钢,
- 调查微观结构机制,负责增强对周期性爬行的抵抗力.
- 探索渐变位架构在设计先进材料中的潜力.
主要方法:
- 高强度奥氏体不钢的制造,具有脱位细胞的梯度等级.
- 在非对称应力循环下测量拉速率的实验测试.
- 微观结构分析以观察变形诱导的变化和细胞结构.
主要成果:
- 开发的钢材的率比粗粒钢材低两到四个数量级.
- 通过马氏体转换到六角密集的纳米层观察到持续的微结构改进.
- 梯度位移架构有效地减轻了循环软化和抑制了应变局部化.
结论:
- 梯度脱位架构为高强度,耐杆材料提供了一个有前途的设计策略.
- 变形诱导的微观结构精细化是抑制杆拉伸的关键.
- 这种方法可以提高结构部件的耐用性和寿命.
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