Hydrogen and aluminium in high-manganese twinning-induced plasticity steel

Given that the penetration of hydrogen into austenite is confined to surface layers following prolonged hydrogen charging, experiments were devised using nanoindentation to assess the influence of hydrogen and aluminium on the mechanical properties. It is found that the reduction in critical load for elastic to plastic transition in the hydrogen-charged layers is smaller in aluminium-alloyed steel, an effect that is not reflected in macroscopic tensile tests. The mechanism by which aluminium works to reduce hydrogen embrittlement is discussed.