Hydrogen-accelerated fatigue crack growth of equiatomic Fe-Cr-Ni-Mn-Co high-entropy alloy evaluated by compact tension testing
Hydrogen-accelerated fatigue crack growth of equiatomic Fe-Cr-Ni-Mn-Co high-entropy alloy evaluated by compact tension testing
复制标题
通过紧凑拉伸试验评估等原子 Fe-Cr-Ni-Mn-Co 高熵合金的氢加速疲劳裂纹扩展
DOI：
10.1016/j.msea.2022.143394
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Tsuzaki Kaneaki
中科院分区：
文献类型：
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作者：
Koyama Motomichi;Mizumachi Shunsuke;Akiyama Eiji;Tsuzaki Kaneaki
我们使用频率为 1 Hz 和室温 (20 °C) 的紧凑拉伸 (CT) 测试，研究了氢对等原子 Fe-Cr-Ni-Mn-Co 高熵合金抗机械长疲劳裂纹扩展的影响。 CT 测试样本在测试前使用 100 MPa 氢气充氢。暴露于氢气后，疲劳裂纹扩展速度加快了三倍。充氢引起的主要变化是晶间裂纹扩展的发生。在沿晶断裂区域观察到条纹特征，表明沿晶裂纹扩展是通过塑性驱动的逐周期机制发生的。更具体地说，我们提出裂纹尖端晶界的位错发射控制晶间疲劳裂纹的扩展。
We investigated the effect of hydrogen on the resistance to mechanically long fatigue crack growth in an equiatomic Fe–Cr–Ni–Mn–Co high-entropy alloy using compact tension (CT) tests at a frequency of 1 Hz and room temperature (20 °C). The CT test specimens were hydrogen charged using 100 MPa of hydrogen gas prior to testing. Fatigue crack growth progressed three times faster after exposure to hydrogen gas. The major change caused by hydrogen charging was the occurrence of intergranular crack growth. Striation features were observed in the intergranular fracture region, indicating that intergranular crack growth occurred via a plasticity-driven cycle-by-cycle mechanism. More specifically, we propose that the dislocation emission from the grain boundaries at a crack tip controls the intergranular fatigue crack growth.