Silver-white, very hard and brittle metal. Chromium is chemically resistant and oxidises only minimally when exposed to humid air. In non-oxidising acids such as HCI, chromium dissolves while hydrogen develops and Cr salts are formed. Due to passivation, oxidising acids do not attack chromium much, even when heated. Chromium coats for corrosion protection or decorative purposes are generated by galvanic chromium-plating, sometimes also via CVD . Chromium steels are characterised by a high stability as well as corrosion and heat resistance. Cutting metals are Co, Cr and W alloys.