[en] The wear behaviour of an austenitic stainless steel is analysed using a tribometer working in pressurised high temperature water (PHTW). The precise contact conditions, low pressure impact and sliding contacts, play an important role on the surface wear in this corrosive medium. The tests which include both impact and sliding are the most severe. The friction films formed during these tests are compared with those obtained with pure oxidation. It is shown that these films participate in the formation of elongated 'indents' observed on the surfaces. Nano-indentation measurements consolidate this hypothesis. (authors)