The helium-to-vacancy (He/V) ratio is a key factor related to the helium bubble hardening mechanisms induced by neutron irradiation in ferritic/martensitic (F/M) steels as advanced nuclear structural materials. According to the helium bubble hardening results in F/M steel irradiated in the spallation neutron source, the interactions between a 1/2<111>{110} edge dislocation and helium bubbles with various sizes of 0.7-3.0 nm in bcc-Fe under irradiation temperatures and room temperature was investigated by using molecular dynamics simulation. The effect of various He/V ratios in the ranges of zero to the highest He/V ratios, 1.85-4.0 of stable helium bubbles with no dislocation loop emission, on the interaction mechanisms was analyzed. The results indicated that the critical resolved shear stress (CRSS) drops rapidly to a very low stress level, and immediately bottoms out and rebounds to a very high stress level, when the He/V ratio increases from 1.0 to the highest He/V ratio. The significant change of CRSS values is not only related to the climbing degree of dislocation after releasing, but also related to the moment when the climb appears. A new repulsion mechanism of interaction between dislocation and bubble was proposed to elucidate the abnormal phenomena of the bottoming rebound of CRSS with a great climbing degree, according to the repelling interaction between helium bubble and superjog of dislocation with both strong compressive stress field.

氦空位（He / V）比是与作为高级核结构材料的铁素体/马氏体（F / M）钢中的中子辐照引起的氦气泡硬化机制有关的关键因素。根据在散裂中子源中辐照的F / M钢中的氦气气泡硬化结果，在bcc-Fe中，1/2111 111 {110}边缘位错与不同尺寸0.7-3.0 nm的氦气气泡之间的相互作用使用分子动力学模拟研究了辐射温度和室温。分析了从零到最高He / V比率范围内的各种He / V比率，1.85-4.0的稳定氦气气泡（没有位错回路发射）对相互作用机理的影响。结果表明，临界解析切应力（CRSS）迅速下降至非常低的应力水平，当He / V比从1.0增加到最高He / V比时，立即触底并反弹到很高的应力水平。CRSS值的显着变化不仅与释放后的脱位的爬升程度有关，而且还与爬升出现的时刻有关。提出了一种新的位错与气泡相互作用的排斥机理，以氦泡与位错超缓动同时具有强压缩应力场的排斥相互作用为依据，阐明了CRSS底部反弹的异常现象。CRSS值的显着变化不仅与释放后的脱位的爬升程度有关，而且还与爬升出现的时刻有关。提出了一种新的位错与气泡相互作用的排斥机理，以氦泡与位错超缓动同时具有强压缩应力场的排斥相互作用为依据，阐明了CRSS底部反弹的异常现象。CRSS值的显着变化不仅与释放后的脱位的爬升程度有关，而且还与爬升出现的时刻有关。提出了一种新的位错与气泡相互作用的排斥机理，以氦泡与位错超缓动同时具有强压缩应力场的排斥相互作用为依据，阐明了CRSS底部反弹的异常现象。