The Oxidation of Corten Steel
During oxidation, the colour varies from, at first, orange to a reddish-brown when the patina has stabilised. Under normal environmental conditions, this occurs in 18-36 months. Essential factors for the correct formation of the patina are alternate cycles of dry/wet, contact with the atmosphere and the catalytic action of sunlight, combined with the absence of permanent stagnant water. It is inadvisable to leave COR-TEN® steel surfaces in marine environments rich in chlorides, as they do not promote oxidation and formation of the protective rust patina. If you do not want to wait for the protective oxide to form naturally, sandblasting or accelerated oxidation treatments can be carried out.