NDT Test Timing of Heat Treatment Status NDT Test Timing of Heat Treatment Status – Many standards require that the timing of NDT testing be performed after heat treatment. Here are 4 common“Fires” for heat treatment. Annealing: The steel work piece is heated to 30-50 ° C above AC3 and held for a period of time to homogenize the austenite structure and refine the grains, followed by slow cooling in the furnace (or buried in sand or lime) to below 500 ° C, a heat treatment process in which air is cooled to room temperature. It can eliminate the defects of coarse structure, ferrite or carbide, composition segregation and internal stress in the workpiece during hot working. Normaliz: A heat treatment process in which a steel workpiece is heated to a suitable temperature above the critical point AC3 or ACCM for a certain period of time to achieve full austenization […]