This study investigated the susceptibility of X80 pipeline steel to hydrogen embrittlement given different hydrogen pre-charging times and hydrogen charging–releasing–recharging cycles in H₂S environment. The fracture strain of the steel samples decreased with increasing hydrogen pre-charging time; this steel degradation could almost be recovered after diffusible hydrogen was removed when the hydrogen pre-charging time was <8 d. However, unrecoverable degeneration occurred when the hydrogen pre-charging time extended to 16–30 d. Moreover, nanovoid formation meant that the hydrogen damage to the steel under intermittent hydrogen pre-charging–releasing–recharging conditions was more serious than that under continuous hydrogen pre-charging conditions. This study illustrated that the mechanical degradation of steel is inevitable in an H₂S environment even if diffusible hydrogen is removed or visible hydrogen-induced cracking is neglected. Furthermore, the steel samples showed premature fractures and exhibited a hydrogen fatigue effect because the repeated entry and release of diffusible hydrogen promoted the formation of vacancies that aggregated into nanovoids. Our results provide valuable information on the mechanical degradation of steel in an H₂S environment, regarding the change rules of steel mechanical properties under different hydrogen pre-charging times and hydrogen charging–releasing–recharging cycles.

中文翻译：

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X 80管线钢在H 2 S环境中的氢脆性：氢充电时间，氢俘获状态和氢充电-释放-充电循环的影响

这项研究研究了X80管线钢在不同的氢气预充电时间和H _2中的氢气充放电-再充电周期下对氢脆的敏感性。S环境。钢样品的断裂应变随着氢预充电时间的增加而减小；当氢的预充电时间小于8 d时，除去扩散的氢后，这种钢的降解几乎可以恢复。但是，当氢的预充电时间延长到16–30 d时，发生了不可恢复的变性。此外，纳米空隙的形成意味着氢在连续的氢预充-释放-再充条件下对钢的破坏比在连续氢预充条件下更严重。这项研究表明，在H ₂中钢的机械降解是不可避免的即使除去了可扩散的氢或忽略了可见的氢诱导的开裂，也可在S环境下进行。此外，钢样品显示出过早的断裂并表现出氢疲劳效应，因为可扩散氢的反复进入和释放促进了聚集成纳米空隙的空位的形成。我们的结果为H ₂ S环境中钢的机械降解提供了有价值的信息，涉及在不同的氢预充电时间和氢充-放-充循环下钢力学性能的变化规律。