Panels made from steel panels: Alloy steels usually containing 10–35% chromium. Chromium, together with low carbon content, gives resistance to corrosion and heat. Other elements, such as nickel, titanium, aluminium, copper, nitrogen, molybdenum, titanium, sulphur, niobium, phosphorus, and selenium, are added to increase corrosion resistance to certain environments, enhance resistance to oxidation and produce special characteristics.