应变控制的低循环疲劳行为和微观结构 热加工压钢在700°C的演变
Pengfei Jin1, Lichao Shi2, Chao Zhao3
1State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China.
Materials (Basel, Switzerland)
|December 31, 2025
概括
这项研究揭示了30Cr2Ni3MoWV热加工压钢的高温疲劳受到循环软化显著影响. 微观结构变化,如碳化物粗化和脱位积累,在高压力下加速故障.
科学领域:
- 材料科学 材料科学 材料科学
- 机械工程 机械工程
- 金工业是金工业的一个方面.
背景情况:
- 热加工压钢对于高温制造工艺至关重要.
- 了解它们在极端条件下的性能,例如在700°C的低循环疲劳,对于运行寿命至关重要.
研究的目的:
- 为了研究低循环疲劳 (LCF) 行为和新型30Cr2Ni3MoWV热加工压钢在700°C的微结构演变.
- 为了将疲劳寿命和软化机制与不同应变幅度下的微观结构变化相关联.
主要方法:
- 高温拉伸试验,以评估柔性和强度.
- 低周期疲劳 (LCF) 测试在不同的应变幅度 (0.2%至0.6%).
- 使用光学显微镜和传输电子显微镜 (TEM) 的微结构分析.
- 开发和优化压力减轻系数模型和Coffin-Manson模型.
主要成果:
- 钢在700°C时表现出良好的柔性 (32%的延长) 和拉伸强度 (460MPa).
- 在较高的应变幅度 (0.6%) 观察到显著的循环软化和快速疲劳寿命缩短.
- 微结构进化包括碳化物粗化 (特别是M23C6),脱位重新排列和马石线扩大.
- 碳化物在0.6%的压力下促进了二次裂纹形成,导致过早失效.
- 优化的Coffin-Manson模型准确地预测了疲劳寿命,偏差最小 (0.01%).
结论:
- 加快软化和减少疲劳寿命与碳化物粗化,脱位积累和二次裂纹有关.
- 这些发现为提高热加工压钢的高温疲劳性能提供了关键的见解.
- 开发的模型为工程应用提供了可靠的疲劳行为预测.
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