(1. 国网安徽省电力有限公司 电力科学研究院，合肥 230601；
2. 合肥工业大学 材料科学与工程学院，合肥 230009；
3. 高性能铜合金材料及成形加工教育部工程研究中心，合肥 230009)
摘 要: 采用电解渗氢与低周疲劳结合的方法，模拟研究Ⅲ型储氢瓶内胆用6061-T6Al合金在高压氢气环境与快速充放氢气过程中力学性能的变化规律，为储氢气瓶长期服役安全可靠性评价提供数据支持。结果表明：在电解渗氢过程中，部分H原子吸附在Al合金表面及表面氧化层中，部分H原子溶入Al合金晶格或晶界处，导致6061Al合金强度及塑性降低，且对合金塑性的影响更加明显。低周疲劳导致6061Al合金屈服强度、拉伸强度与屈强比上升，塑性下降，且随着σmax的增大，拉伸断面上呈现更多的脆性断裂特征。在低周疲劳与电解渗氢共同作用下，6061Al合金强度小幅增大，塑性持续降低，且随着σmax的增加，塑性下降幅度增加，拉伸断面准解理断裂特征愈加显著，服役可靠性明显降低。
关键字: 储氢气瓶；6061Al合金；电解渗氢；低周疲劳；拉伸试验
（1. Electric Power Research Institute, Anhui Electric Power Co., Ltd., State Grid, Hefei 230601, China;
2. School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China;
3. Engineering Research Center of High-performance Copper Alloy Materials and Processing, Ministry of Education, Hefei 230009, China）
Abstract:The method combined with electrolytic hydrogenation and low-cycle fatigue was employed to simulatively study the change of mechanical properties of the 6061-T6 Al alloy, which was used as the liner of type III hydrogen storage cylinder in high-pressure hydrogen atmosphere and in the process of rapid charge/discharge hydrogen. It would provide data support for evaluating the long-term service safety and the reliability of the hydrogen storage cylinder. The results show that during electrolytic hydrogenation, some of the H atoms are adsorbed on the surface and surface oxide layer of the Al alloy, and others are dissolved into the lattices and grain boundaries of the Al alloy. It results in the reduction of strength and plasticity of the 6061Al alloy. Further, the effect of electrolytic hydrogenation on the plasticity of the Al alloy is more obvious. Low-cycle fatigue brings about the increases of yield strength, tensile strength and ratio yield-to-tensile strength, but the decrease of plasticity of the Al alloy. As increasing σmax, more brittle fracture on the tensile fracture surface of the Al alloy samples is presented. On combination of electrolytic hydrogenation and low-cycle fatigue, the strength of the 6061Al alloy increases slightly, however, the plasticity of the alloy decreases persistently. As increasing σmax, the reduction of plasticity of the 6061Al alloy speeds, and the quasi-cleavage fracture characteristic of tensile fracture surface of the Al alloy samples is more prominent, which cause the apparent decrease of service reliability of the 6061Al alloy.
Key words: hydrogen storage cylinder; 6061Al alloy; electrolytic hydrogenation; low-cycle fatigue; tensile test
