Effect of Hydrogen and Hydride on Fatigue Cracking Rate of Zirconium-Based Alloys and Its Estimation
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摘要: 采用紧凑拉伸(CT)试样,研究了不同氢含量的Zr-4及Zr-Sn-Nb合金在室温下疲劳加载裂纹扩展(da/dN)行为,用扫描电镜观察了断口形貌。结果表明,氢含量对疲劳裂纹扩展速率影响微弱,疲劳断裂受通常的裂纹萌生、稳态扩展和瞬间断裂机制控制。根据疲劳裂纹扩展机理,导出了裂纹扩展门槛值ΔKth的关系式,得出了一个描述疲劳裂纹扩展速率(da/dN)与材料性能常数之间的关系式,该关系式可用于预测材料的疲劳裂纹扩展速率。用锆合金实验数据对(da/dN)预测表达式进行验证,结果表明,预测值与实验值吻合较好。Abstract: In this paper, compact toughness samples are used to study the fatigue cracking prolongation behaviors of Zr-4 and Zr-Sn-Nb alloys with different hydrogen contents. Test results indicate that the hydro- gen contents have little effect on the fatigue cracking rate, and fracture behavior is controlled by the nature fatigue cracking mechanism, which include crack budding, stable prolonging and rapid ultimate fracture. According to the mechanism of fatigue cracking, the relationship of fatigue cracking rate (da/dN) and general properties of materials has been induced. In term of this relationship, calculating values of fatigue crack rate of zirconium-based alloys are consonant with the experimental values.
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Key words:
- Fatigue cracking prolongation /
- Zirconium alloys /
- Hydrogen
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