揭示堆叠故障驱动的相位过渡,延迟Fe-Co-Cr-Ni-Mo-C基中等合金中的冷却性断裂
Hui Ding1, Zhenhang Du1, Haifeng Zhang1
1Central Iron and Steel Research Institute, Beijing 100081, China.
Materials (Basel, Switzerland)
|June 19, 2024
概括
这项研究研究了FeCoCrNiMoCx中等合金,揭示了马氏体转化增强了冷强度和柔性. Mo4C1合金在不同温度下表现出最佳的机械性能,在极寒条件下表现出色.
科学领域:
- 材料科学 材料科学 材料科学
- 金工业是一种金工业.
- 机械工程 机械工程
背景情况:
- 中等合金 (MEAs) 正在探索先进的应用.
- 对于在极端环境中使用的材料来说,了解冷条件下的变形机制至关重要.
- 低温破裂和机械性能降解是金属材料面临的重大挑战.
研究的目的:
- 研究基于FeCoCrNiMoCx的中合金在室温 (R.T.),77 K和4.2 K的拉力变形机制.
- 确定导致增强机械性能和延迟冷骨折的因素.
- 为了确定在不同温度下强度-柔性平衡的最佳合金组成.
主要方法:
- 在RT,77K和4.2K时对FeCoCrNiMoCx合金进行拉伸测试.
- 分析微缺陷的形成和相位转换 (马丁晶转换).
- 应变硬化机制的表征,包括结合诱导的可塑性 (TWIP) 和马氏体转化诱导的可塑性 (TRIP).
主要成果:
- 在冷温度下,FeCoCrNiMoCx合金表现出优越的机械性能.
- 双胞胎诱导可塑性 (TWIP) 在R.T.主导应变硬化,而马氏体转化诱导可塑性 (TRIP) 在77 K和4.2 K主导.
- 碳化物沉和位密度增加增强强度;减少堆叠故障能量 (SFE) 促进结合和马氏体转化,提高柔性.
- Mo4C1合金表现出最佳的强度-柔性,达到1670 MPa的抗拉强度和在4.2K时80.0%的延伸.
结论:
- 马氏体转化是延缓冷裂变和提高这些合金的可塑性的一个关键机制.
- 组成,温度和变形机制之间的相互作用决定了合金的性能.
- FeCoCrNiMoCx系统,特别是Mo4C1合金,为在低温条件下要求高性能的应用提供了极好的潜力.
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