Abstract Carbon migration in bcc-iron drives the kinetics of numerous phenomena occurring during ageing of steels, such as segregation at structural defects and iron-carbide precipitation. Internal stresses are often encountered in steel microstructures and are known to affect the diffusivity of carbon. The effect of pressure on carbon diffusivity is related to the carbon migration volume. Unfortunately, theoretical and experimental studies on this migration volume are scarce and sometimes contradictory with one another. In this paper, we provide new ab initio results on carbon migration and compute the effect of an applied pressure on diffusivity. Our results are consistent with known crystallographic and relaxation data. They show that carbon diffusivity in bcc-iron can be enhanced by applying compressive pressure, a counter-intuitive and unusual effect in steels.

中文翻译：

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重新审视压力对铁中碳迁移的影响

摘要 bcc 铁中的碳迁移驱动了钢时效期间发生的许多现象的动力学，例如结构缺陷处的偏析和碳化铁沉淀。内应力经常出现在钢的微观结构中，并且已知会影响碳的扩散率。压力对碳扩散率的影响与碳迁移量有关。不幸的是，关于这一迁移量的理论和实验研究很少，有时相互矛盾。在本文中，我们提供了关于碳迁移的新的 ab initio 结果，并计算了施加压力对扩散率的影响。我们的结果与已知的晶体学和弛豫数据一致。他们表明，通过施加压缩压力可以提高 bcc-iron 中的碳扩散率，