Homogenizing annealing is an annealing process in which an ingot or casting of a certain alloy is heated to a higher temperature below the solidus line of the alloy, kept warm for a long time, and then slowly cooled. Also called diffusion annealing.
Due to the fast cooling rate under industrial production conditions, the structure of the ingot or sand casting after condensation is in a non-equilibrium state to varying degrees, which is mainly manifested by the occurrence of intragranular segregation (also known as dendrite segregation, that is, the inconsistency of the chemical composition within a grain). uniform), reducing the performance of the ingot or casting.
During homogenization annealing, the elements in the alloy undergo solid-state diffusion, which can eliminate or reduce intragranular segregation, thereby improving the properties of the ingot or casting. In order to accelerate atomic diffusion and shorten the annealing time, the homogenization annealing temperature is generally very high, alloy steel is usually 1050~1200°C, and non-ferrous alloy ingots are generally close to the actual melting point of the alloy.
The homogenization annealing temperature is high, the time is long, the Autometalparts oxidation loss is serious, and it is energy-consuming and time-consuming. Therefore, it is generally only used for alloys with complex composition and serious segregation and alloy steel for certain important purposes.