Rotary piercing of the deformation process should be divided into four sections, the district called the perforator preparation area (ie, solid round tube rolling zone). Zone is perforated to prepare and successfully implement a bite, this section is along the perforation direction (axial) advancing gradually in diameter is compressed due to the deformation of the surface of the roll inlet cone taper, the compressed portion of the metal part of the lateral flow, the seat material from round oval cross-section, and the other longitudinally extending metal (mainly gastric metal extension), so the front end of the blank form a "bell" shape depression. Centering on and nose holes ensure alignment of the head tube center, thereby reducing waste pipe uneven.
District called perforated zone, the area's role is perforated, that is to wear an empty area of solid billet length from the metal to meet with the head cone head job until the end. Another distortion is mainly characterized by thinning. Since the surface of the roll between the plug surface and gradually decreases in Yap. So as the forward rotation of the mother pipe, wall thickness of the tube wall is gradually compressed by the compression of the metal, part of lateral flow (expanding), another Xi K Activity (extended). Because lateral deformation of the guide plate block effect, so the main vertical. Lateral deformation of the pipe cross-section resulting in shortage oval. Deformation in this area is a big stretch, extension coefficient can be achieved, which is the area known as helical rolling dog jarring area, the segment's main role is jarring (both positive) wall, Piper walls dimensional accuracy and inner and outer surface quality. As head bus and the bus rolls his recent compression on the wall so little spiral steel corrosion are mainly from the whole effect, rolling cross-section is still Tsuen, but the ellipse is gradually reduced. m area is the length of the head from a metal rolling cart: Gung encounter to leave the plug jarring cone so far.
Zone IV to turn round District, which is the role of the shortage of oval tube, by the rotation of the solitary reduced diameter reduction on until the reduction to zero of the waste pipe turn round so far. Length is very short, this section of the deformation is essentially no shortage of head hollow white plastic tube deformation process, as this area is very short and small deformation force is generally not.
