Microstructural Homogenization Degree

Diffusion annealing is done to homogenize the structure. Through heat treatment, the alloying elements migrate in the matrix and balance out local differences, such as those caused by segregation during casting. If you skip it, the material can tend to crack during welding or forming because the zones react differently. So: bring the part to the right annealing temperature before further processing and hold it long enough, then you'll have a more uniform structure and less trouble in the shop.