Chemical composition dependence of the strength and ductility enhancement by solute hydrogen in Fe-Cr-Ni-based austenitic alloys
Chemical composition dependence of the strength and ductility enhancement by solute hydrogen in Fe-Cr-Ni-based austenitic alloys
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Fe-Cr-Ni 基奥氏体合金中固溶氢增强强度和延展性的化学成分依赖性
DOI：
10.1016/j.msea.2022.142681
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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：
--
作者：
Nishida Haruki;Ogawa Yuhei;Tsuzaki Kaneaki
对5种工业Fe-Cr-Ni基奥氏体合金在加压气体环境中预热充氢后进行了拉伸试验。铬和镍浓度的差异对氢的溶解度以及溶解氢对合金力学性能的影响都有显著的影响。氢的溶解度随着铬含量和铬/镍组成比的增加而增加，导致固溶体硬化增加，每原子百分比的溶质氢的硬度达到≈G/1000(G：剪切模数)。此外，在层错能相对较低(Ni含量较低)的合金中，氢促进了形变孪晶的形成，即使在非氢化状态也会发生形变孪晶。随着孪晶密度的增大，变形后期的加工硬化能力增强，延伸率均匀提高，从而延缓了塑性失稳的发生。结合实验结果和对其他奥氏体材料氢响应的假设，推导出促进氢强化和延伸化的必要条件。
Tensile tests of five commercial Fe–Cr–Ni-based austenitic alloys were conducted after thermal hydrogen precharging in a pressurized gaseous environment. The divergence in Cr and Ni concentrations affected the hydrogen solubility significantly as well as the impacts of dissolved hydrogen on the mechanical performance of the alloy. Hydrogen solubility increased with increasing Cr content and Cr/Ni compositional ratio, bringing about an escalating solid-solution hardening with a magnitude of ≈G/1000 (G: shear modulus) per atomic percent of solute hydrogen. Furthermore, hydrogen facilitated deformation twinning in alloys with relatively low stacking fault energy (lower Ni content), in which deformation twinning occurred even in a nonhydrogenated state. Augmenting the twin density enhanced the work-hardening capability at the later deformation stage, giving rise to the improvement of uniform elongationviaretarded onset of plastic instability. Consolidating the experimental results and hitherto-understood hypothesis on the response to hydrogen of other austenitic materials, the essential conditions for promoting hydrogen-related strengthening and ductilization were deduced.