What does sticking refer to in a hot rolling operation?

Sticking in a hot rolling operation refers to the adherence of the workpiece's surface to the rolls. This phenomenon occurs due to the high temperatures involved in the process, which can lead to surface oxidation and increased friction between the metal and the rolls. When sticking occurs, it can hinder the smooth rolling action, resulting in defects in the material and potentially impacting the dimensional accuracy and surface finish of the finished product.

Understanding this concept is crucial for optimizing the hot rolling process. Effective lubrication and temperature control are often implemented to minimize sticking, ensuring that the material flows correctly through the rolling mill and reduces the risk of damage to both the workpiece and the rolls themselves.

The other options describe different phenomena unrelated to the specific issue of sticking in hot rolling. For instance, the formation of burrs is related to cutting processes, and incorrect alignment of rolls pertains to setup issues, while cooling of the workpiece before rolling would typically be avoided in hot rolling as it aims to manipulate the metal while it's still malleable due to heat.