Corrosion resistance properties and hydrogen embrittlement protection efficiency of single-layer and multi-layer metal and ceramic films deposited on SS316L substrates

Hydrogen is a promising source of clean energy. However, the tanks used to store hydrogen fuel are prone to hydrogen embrittlement and are thus at risk of stress cracking and catastrophic failure. Accordingly, this study deposited single-layer and double-layer Zr, Al, SiO2, Al2O3, Al@Al2O3, and Al@SiO2 films on 316L stainless steel substrates and examined their feasibility as protective coatings by measuring their anti-corrosion properties and hydrogen permeation currents. The results showed that the single-layer Al2O3 film had a higher corrosion resistance than the single-layer SiO2 film and bare 316L substrate. Among all the coatings, the Al@Al2O3 double-layer coating exhibited the highest protection efficiency of 95 %. Moreover, it showed the lowest hydrogen penetration current density (1.08 x 10−3 A/cm2), the longest hydrogen embrittlement time (16000 s), and the lowest hydrogen content (0.008 mol/cm3). In other words, the Al@Al2O3 double-layer coating combined superior corrosion resistance with excellent hydrogen permeation suppression. Consequently, it is a promising material for enhancing the safety and longevity of hydrogen storage tanks in practical applications. •Double-layer as protective coatings on 316L stainless steel substrates measured their anti-corrosion properties and hydrogen permeation currents.•The Al@Al2O3 double-layer coating exhibited the highest protection efficiency of 95 %.•A low hydrogen penetration current density of 1.08 x 10−3 A/cm2 could be achieved.•The Al@Al2O3 coating appears to be a promising solution for enhancing the safety of hydrogen storage tanks.