Advanced high strength steels (AHSS) are very promising for e.g. structural components in car bodies due to their high strength combined with large elongations. These steel types are however very prone to hydrogen embrittlement (HE). HE is characterized by a decrease in the metal’s mechanical properties. It might also lead to unpredictable failures due to hydrogen induced cracking (HIC). Hydrogen originates either from the production process or in use by contact with a hydrogen containing environment. The present project will focus on HE in twinning induced plasticity (TWIP) steel which is an austenitic AHSS. Austenite is the high temperature variant of iron, stabilized at room temperature by addition of over 17 wt% of manganese. The HE/HIC phenomenon and the responsible mechanism in TWIP steels is not well understood yet. Accurate hydrogen charging and test methods will be developed. A literature based TWIP steel will be used. Additionally, aluminium addition will be investigated as it is reported to have a beneficial influence on the HE sensitivity of TWIP steels. This effect might be a bulk effect, a surface effect or a combination of both. Alloy design, together with high resolution material and surface characterization techniques will be used to investigate the role of the aluminium in these materials.