This International Standard specifies the method for high temperature corrosion testing of metallic materials by embedding in a corrosive powder made up of salt, ash, and/or other solids and exposing them to high temperature in a controlled gas environment to evaluate their corrosion resistance.Two options exist: fully embedding and partially embedding.Fully embedding is used in cases in which a mass change measurement is required.Partially embedding is used to investigate three potentially different interaction zones on a single test piece, i.e. the embedded part, the non-embedded part, and the gas/powder interface region. Therefore, gravimetric measurements are not appropriate and metallographic investigations are necessary instead.This International Standard does not cover methods where test pieces are immersed in a liquid or cases in which a surface deposit is applied to the test pieces. These methods are covered in ISO 17245 and ISO 17224, respectively.