Upset Underfill. A depression on the outside or inside of an upset caused by insufficient flow of metal to completely fill out the upset to the desired shape.

• 加厚部分充型不良。由于金属流动不充分，未能完全充满加厚模以获得所需的形状而引起的加厚部分外表面或内表面上的凹陷处。