The importance of post-forging cooling

Why is it cooled after forging

The post-forging cooling of forgings is as important as the pre-forging heating and forging  deformation process. Sometimes, the normal heating standard and proper forging of steel materials can ensure that high-quality forgings can be obtained. However, if the post-forging cooling method is not properly selected, the forgings may be cracked or even scrapped.

Definition

 Cooling after forging refers to the process of cooling from the final forging temperature to room temperature after finishing forging.

 Common defects of post-forging cooling include cracks, white spots, etc.

Crack

 Cooling crack is caused by internal stress generated during cooling. Because of the low temperature and poor plasticity of forgings in the later stage of cooling, the risk of internal stress in cooling is greater than that in heating.

White spot

 White spot is the result of hydrogen enrichment and tissue stress.White spots mostly occur in pearlite and martensite alloy steels, carbon steels are lighter, austenite and ferrite steels rarely find white spots, and ledeburite alloy steels also don't find white spots.