This study investigated the hydrogen-related fatigue fracture in 2Mn-0.1C steel having a lath martensite microstructure. The presence of hydrogen significantly reduced the fatigue life. The transgranular surface was a main component in each stress range of the uncharged specimen, while the intergranular surface was frequently observed in the hydrogen-charged specimen. The crystallographic orientation analysis by electron backscattering diffraction revealed that the cracks mainly propagated along {011} planes regardless of the presence of hydrogen. Compared with the uncharged specimen, however, plastic deformation was localized near the fatigue crack in the hydrogen-charged specimen. According to the reconstructed fracture process by fracture surface topography analysis, the hydrogen-related fatigue fracture was discontinuous and composed of isolated nucleation of intergranular cracks and quasi-cleavage crack propagation initiated at the pre-existing intergranular cracks.

本研究调查了具有板条马氏体显微组织的 2Mn-0.1C 钢的氢相关疲劳断裂。氢的存在显着降低了疲劳寿命。在不带电试样的各个应力范围内，穿晶面是主要成分，而在充氢试样中经常观察到晶间面。通过电子背散射衍射进行的晶体取向分析表明，无论是否存在氢，裂纹主要沿 {011} 面传播。然而，与不带电试样相比，充氢试样的塑性变形集中在疲劳裂纹附近。根据断裂面形貌分析重建的断裂过程，