含氢NZ2锆合金疲劳裂纹扩展行为

Fatigue Crack Propagation Behavior of NZ2 Zirconium Alloy with Different Hydrogen Contents

摘要:

利用板材标准M(T)试样研究了4种不同氢含量(0，200，450，730 mg/g) NZ2锆合金的疲劳裂纹扩展行为。发现不论含氢量的高低，裂纹稳态扩展区的裂纹扩展行为均符合Paris幂律关系，即 da/dN=C(DK)n，但随着氢含量的增加，n值不断减小；含氢量增加导致NZ2合金塑性变形能力降低，疲劳裂纹扩展速率增加，尤其是氢含量较高时表现更为明显。

Abstract:

Fatigue crack propagation behavior of an advanced Zr-Sn-Nb alloy NZ2 with different hydrogen contents (0, 200, 450, and 730 mg/g) was investigated by standard M(T) specimens. The results showed that stable crack propagation behavior obeyed the Paris Law, i.e. da/dN=C(DK)n, whether the hydrogen content is high or low. But the power exponent n of the Paris Law was decreased with the hydrogen content increasing; the increment of hydrogen content can decrease the ductility of NZ2 alloy and enhance the fatigue crack growth rate, especially when the specimens have higher hydrogen content.