A nickel-chromium alloy with addition of aluminium to offer optimum resistance to metal dusting attack of any available conventional nickel-based alloy. The high chromium content gives excellent resistance to oxidation and sulphidation. The addition of aluminium improves resistance to other high temperature corrosion mechanisms. Alloy 693 exhibits excellent resistance to oxidation and carburisation at temperatures up to 1150°C (2100°F). The alloy’s resistance to metal dusting attack makes it especially suitable for systems used to generate synthesis gas and in hydrogen reformers.