What is the foundation of classification of cold and hot working?
Cold and hot working:
Changing the shape of material by extrusion, forging, rolling, drawing involves plastic deformation of metals. When deformation is carried out at temperature below the recrystallization temperature, it is known as cold working such as cold rolling, drawing, pressing, spinning, impact extrusion.
When deformation is at temperature higher than recrystallization temperature the process is termed as hot working such as forging, rolling, extrusion.