What is the purpose of annealing?

What is the purpose of annealing?

1. Improve or eliminate various structural defects and residual stress caused by steel during casting, forging, rolling and welding, and prevent deformation and cracking of the workpiece.
2. Soften the workpiece for cutting.
3. Refine the grains and improve the structure to improve the mechanical properties of the workpiece.
4. Prepare the structure for final heat treatment (quenching, tempering).