Generally speaking, steel shot should be solid. However, in some cases, the steel shot becomes hollow. So why does this happen?
1. Internal gas generation
One of the reasons for the hollowness of steel shot is the generation of internal gas. In the production process of steel shot, the steel is drawn into a die-casting mold controlled by grouting, and the steel ball is solidified using a rapid cooling method. During this process, air and other gases may not be completely formed and excluded, resulting in some pores inside the steel shot, forming a hollow structure.
2. Inward retraction
The second reason for the hollowness of steel shots is internal shrinkage, which is also the cause of hollowness. During the cooling process of the steel shot, due to factors such as different internal temperatures and uneven internal shrinkage, voids appear inside the steel shot, forming a hollow structure.