为了评估极紫外光刻（EUVL）机结构材料的氢损伤行为，提出首先采用低压气相充氢的方法获得不同充氢时间下材料内的氢含量及其变化趋势，同时采用电解充氢恒载荷拉伸试验获得不同氢含量材料的门槛应力值、氢脆指数及变化趋势；然后将两者结合从而评判一种材料在低压气相氢环境中的氢脆敏感性及其随时间的变化趋势。采用该试验方法对比测试了304不锈钢（304SS）和65Mn弹簧钢在低压环境中的氢损伤行为，结果表明：两种材料置于室温10 Pa氢环境的时间越长，其氢脆敏感性越低，越不容易发生氢损伤；且材料内氢含量相同的条件下，65Mn弹簧钢比相304SS的氢脆敏感性高。该试验方法可用于EUVL中大部分结构材料的氢损伤行为评估，且试验结果具有指导意义。

In order to evaluate the hydrogen embrittlement of materials in extreme ultraviolet lithography (EUVL) vacuum system, a novel test method was proposed to speculate the hydrogen sensibility under low-pressure hydrogen condition and its time-evolution. Firstly, the material's hydrogen concentration and variation trend could be obtained using a low-pressure gaseous hydrogen charging set and a hydrogen content analyzer. In the meantime, the fracture threshold stress and hydrogen embrittlement exponent of materials with various hydrogen concentrations could be acquired using a constant load set under electrochemical hydrogen charging condition. Combining the above two, the fracture threshold stress and hydrogen embrittlement exponent in different periods of time for materials under low-pressure gaseous hydrogen condition could be calculated theoretically at last. With the purpose of verifying the correctness of the new principle and having a wise judgement, 304SS and 65Mn were chosen as representative materials and their hydrogen susceptibility was measured using this method. The results reveal that the longer the time for the material in the 10Pa hydrogen environment, the lower the possibility for the material to fail due to hydrogen embrittlement. Under a certain concentration condition, 65Mn showed a higher hydrogen susceptibility than 304SS, which is in accord with the literature. It is indicated that the test method and results have practical value in the EUVL material selection.