Defects occur on forging despite it being one of the best manufacturing processes that give better mechanical properties. These defects need to be examined and can be prevented. Forging defects can be controlled by careful consideration of work material volume, good designing of the forging die, and the process.
To avoid this forging defect, care should be taken during the operation and the smith must have experience in forging. Types of forging defects include unfilled section, cold shut, scale pits, die shaft, flakes, improper grain growth, incomplete forging penetration, surface cleaning, and residual stresses in forging.
Read more: Different types of forging operations
Types of forging defects
Below are the various types of forging defects that might occur during the process:
These types of forging defects left some portions in the object unfilled. It is caused by poor design of die, less raw material, poor forging techniques, and poor heating. To avoid the occurrence of the defect, proper care must be taken on the die design, heating, and there should be enough raw materials.
These types of forging defects occur as small cracks at the corners of the object. It is caused by improper design of the forging die, sharp corners of the object, and excessive chilling of the forged product. These forging defects can be avoided when the fillet radius of the die is increased.
This forging defect occurs due to improper cleaning of the forged surface. Scale pit is usual in forging carried out in an open environment. It causes irregular deputations on the forging surfaces. This defect can be avoided by adequate cleaning of the forged surface.
Die shift forging defect is caused when the upper and lower dies are not aligned with each other. This will result in improper dimensions of the product. The defect can be avoided when the die is properly aligned. It can be done by placing half portion of the workpiece on the upper die and half on the lower die so that both portions can match.
These types of forging defects occur due to improper cooling of the forged product. It is internal cracks caused when the forged products cool quickly, and it reduces the strength of the forged product. Flakes can be avoided when proper cooling is performed.
Improper grain growth:
These forging defects are caused by improper flow of metal during the casting process which changes the predefined grain of the product structure. It can be avoided by performing a better design of the die.
Incomplete forging penetration:
These types of forging defects occur due to light or rapid hammer blow that lead to incomplete forging. It can be prevented by proper usage or control of the forging press.
Surface cracking is forging defects that arise when the forging operation is performed at low temperature which leads to the occurrence of cracks on the workpieces. It can be controlled by working at a proper temperature.
Residual stresses in forging:
This type of forging defect takes place when the forged parts are not properly cooled. It can be caused by much rapid cooling and can be prevented by slow cooling of the forged part.
That is all for this article, where the various types of forging defects are explained. I hope you get a lot from the reading, if so, kindly share with other students. Thanks for reading, see you next time!