The influences of hydrogen on the mechanical properties and the fracture behaviour of Fe-22Mn-0.6C twinning induced plasticity steel have been investigated by slow strain rate tests and fractographic analysis. The steel showed high susceptibility to hydrogen embrittlement, which led to 62.9% and 74.2% reduction in engineering strain with 3.1 and 14.4 ppm diffusive hydrogen, respectively. The fracture surfaces revealed a transition from ductile to brittle dominated fracture modes with the rising hydrogen contents. The underlying deformation and fracture mechanisms were further exploited by examining the hydrogen effects on the dislocation substructure, stacking fault probability, and twinning behaviour in pre-strained slow strain rate test specimens and notched tensile specimens using coupled electron channelling contrast imaging and electron backscatter diffraction techniques. The results reveal that the addition of hydrogen promotes planar dislocation structures, earlier nucleation of stacking faults, and deformation twinning within those grains which have tensile axis orientations close to <111>//rolling direction and <112gt;//rolling direction. The developed twin lamellae result in strain localization and micro-voids at grain boundaries and eventually lead to grain boundary decohesion.

通过慢应变速率试验和分形分析，研究了氢对Fe-22Mn-0.6C孪晶诱导塑性钢力学性能和断裂行为的影响。该钢表现出极高的氢脆性，这导致了3.1和14.4 ppm的扩散氢分别使工程应变降低了62.9％和74.2％。随着氢含量的增加，断口表面显示出从延性转变为脆性为主的断口模式。通过研究氢对位错亚结构，堆垛层错概率，使用耦合电子通道对比成像和电子反向散射衍射技术在预应变慢应变速率试样和缺口拉伸试样中的孪生行为。结果表明，氢的添加促进了平面内的位错结构，较早的堆垛层错成核以及在拉伸轴取向接近<111> //轧制方向和<112> //轧制方向的那些晶粒内的变形孪生。发达的双晶层导致应变局部化和在晶界的微孔，并最终导致晶界的脱粘。在那些拉伸轴取向接近<111> //轧制方向和<112> //轧制方向的晶粒内，变形孪生。发达的双晶层导致应变局部化和在晶界的微孔，并最终导致晶界的脱粘。在那些拉伸轴取向接近<111> //轧制方向和<112> //轧制方向的晶粒内，变形孪生。发达的双晶层导致应变局部化和在晶界的微孔，并最终导致晶界的脱粘。