Incoloy refers to a range of superalloys produced by the Special Metals Corporation group of companies. They are mostly nickel-based, and designed for excellent corrosion resistance as well as strength at high temperatures; there are specific alloys for resistance to particular chemical attacks (e.g. alloy 020 is designed to be resistant to sulphuric acid, DS to be used in heat-treating furnaces with reactive atmospheres and many heat cycles)