2:52 PM , Posted in Forging Defects
Though forging process give generally prior quality product compared other manufacturing processes. There are some defects that are lightly to come a proper care is not taken in forging process design.
A brief description of such defects and their remedial method is given below.
(A): Unfilled Section:
In this some section of the die cavity are not completely filled by the flowing metal. The causes of this defects are improper design of the forging die or using forging techniques.
(B): Cold Shut:
This appears as a small cracks at the corners of the forging. This is caused manely by the improper design of die. Where in the corner and the fillet radie are small as a result of which metal does not flow properly into the corner and the ends up as a cold shut.
(C): Scale Pits:
This is seen as irregular depurations on the surface of the forging. This is primarily caused because of improper cleaning of the stock used for forging. The oxide and scale gets embedded into the finish forging surface. When the forging is cleaned by pickling, these are seen as depurations on the forging surface.
(D): Die Shift:
This is caused by the miss alignment of the die halve, making the two halve of the forging to be improper shape.
These are basically internal ruptures caused by the improper cooling of the large forging. Rapid cooling causes the exterior to cool quickly causing internal fractures. This can be remedied by following proper cooling practices.
(F): Improper Grain Flow:
This is caused by the improper design of the die, which makes the flow of the metal not flowing the final interred direction.