中文摘要：

热浸镀锌-5％铝镀层钢材在海洋环境中使用时可能存在氢脆问题。采用慢应变速率拉伸实验法，结合扫描电镜分析，研究了锌-5％铝镀层钢材在海水中的氢脆敏感性。发现锌-5％铝镀层对钢材基体进行阴极保护引起的氢渗透，可显著降低钢材的断后延伸率和能量密度，使钢材的断裂方式由韧性向准解理转变，提高了其在海水中的氢脆敏感性。

英文摘要：

Hydrogen embrittlement of hot-dip Zn-5%Al coated steel exposed to seawater was investigated by slow strain rate tensile test and scanning electron microscopy technique. It was found that the hydrogen absorption and permeation, which result from the sacrificial protection of the steel substrate afforded by the Zn-5%Al coating, remarkably reduced the percentage elongation after fracture of hot-dip coated steel specimens, and the energy density as well; meanwhile, the fracture characteristics of the hot-dip coated steel changed from ductile to quasileavage, i.e., such steel showed a high susceptibility to hydrogen embrittlement in seawater. The mechanism of hydrogen embrittlement was also discussed.