Abstract

Hydrogen behavior and corresponding mechanical degradation were examined in TaTi-RAFM and EUROFER97 steels. Increased Ta content with Ti addition decelerates the hydrogen diffusion but increases the solubility in the lattice. It is mainly led by the higher fraction of Ta-rich MC carbides and dislocation density in TaTi-RAFM steel. Overall activation energy of hydrogen trapping of investigated steels is evaluated to be 25.3 ~ 25.6 kJ/mol in the tempered condition. The activation energy increases to nearly 30 kJ/mol when the steels are re-austenitized and quenched. Higher activation energy with increased dislocation density indicates that the dislocation provides for trap site with higher activation energy than Ta-rich MC carbide. Mechanical degradation by hydrogen with respect to the yield strength, tensile strength and uniform elongation could not be observed in all investigated steels. The presence of hydrogen only has influence on the loss of post-uniform elongation. For a given charging time, the loss of post-uniform elongation is more remarkable in TaTi-RAFM steel due to the larger hydrogen uptake.

Graphic Abstract

中文翻译：

---

钛添加还原活化铁素体-马氏体钢的氢行为

抽象的

在TaTi-RAFM和EUROFER97钢中检查了氢行为和相应的机械降解。添加Ti时增加的Ta含量会降低氢的扩散，但会增加其在晶格中的溶解度。其主要原因是富Ta的MC碳化物的比例较高，而TaTi-RAFM钢中的位错密度较高。在回火条件下，研究钢的总氢捕获活化能估计为25.3〜25.6 kJ / mol。当钢被重新奥氏体化和淬火时，活化能增加到将近30 kJ / mol。较高的活化能和较高的位错密度表明，与富含Ta的MC碳化物相比，位错为陷阱位点提供了较高的活化能。氢相对于屈服强度的机械降解，在所有研究的钢中均未观察到抗拉强度和均匀伸长率。氢的存在仅影响均匀后伸长率的损失。对于给定的充电时间，由于更大的氢气吸收量，TaTi-RAFM钢的均匀后伸长率的损失更加明显。

图形摘要