Dr. Dmitri Kopeliovich
Forging is a compressive metal forming process, involving shaping a metal piece by hammer, press or rolls.
Press forging achieves more uniform internal structure due to transmitting deformation to the interior layers of the worpiece. This effect is particularly important when large shafts or other thick parts are forged.
Forging structure is a result of breaking coarse cast structure and forming at first stage grain structure having fibrous character with elongated grains oriented in the direction of the forging stresses. The fibrous grain structure is then converted to the fine equiaxed grain structure (recrystallization process).
Small shrinkage and gas pores are closed up in the hot forging operation, non-metallic inclusions break up and distribute more uniformly.