During this process, each time the wire is pulled over, the surface hardens due to the high friction temperature. So basically every time you pull it you have to annealing it in the furnace. On the one hand, it is to reduce the surface hardness. On the other hand, during the process of wire pulling, only the surface is deformed, and the center is unchanged. So there’s a lot of stress inside. Therefore, it is necessary to rely on annealing to eliminate the internal stress, so that the wire becomes soft again to eliminate the stress before being drawn again.
