Piercing tools of seamless steel pipes

Understanding and selecting the right piercing tool is vital for producing seamless steel pipes efficiently and with high quality. The piercing tool comprises several components, each playing a unique role in the process. Proper use and maintenance of these components ensure optimal deformation, precise diameter control, and improved productivity. The primary components of the piercing tool are as follows.

1. Roller

The roller serves as the main drive deformation tool and consists of three key parts: the inlet cone, the rolling belt (also known as the compression belt), and the outlet cone. Each part has specific functions:

Inlet Cone: This part guides the tube blank into the perforation process, initiating the deformation.

Rolling Belt: Acts as a transition zone between the inlet cone and the outlet cone, ensuring smooth progression of the tube blank through the roller.

Outlet Cone: Responsible for reducing wall thickness, leveling the capillary tube's surface, ensuring uniform wall thickness, and completing the capillary return process.

2. Guide

The guide is a stationary external deformation tool designed to stabilize the rolling line and control the diameter of the capillary tube. It restricts lateral deformation, thereby preventing excessive expansion. The guide has a similar profile to the roller and is divided into three sections:

Inlet Section: Introduces the tube blank into the guide.

Transition Section: Smoothly transitions the tube blank through the guide.

Outlet Section: Controls the capillary tube's diameter and guides it out, limiting expansion.

3. Head

The head is a crucial internal deformation tool within the puncher, analogous to the inner roll of a steel ring mill. It is fixed axially within the deformation zone, supported by the top bar. The head is essential for converting the tube blank from a solid to a hollow form. It includes four sections: the nose, the perforated cone, the flat belt, and the reverse taper belt.

Nose: Aligns with the blank's centering hole during piercing, facilitating the process and applying axial force to the tube's center to prevent cavity formation.

Perforated Cone: Performs the initial perforation of the tube blank, reducing the wall thickness of the emerging capillary tube.

Flat Belt: Matches the cone angle at the roll exit, ensuring uniform wall thickness and flattening the capillary tube.

Reverse Taper Belt: Prevents internal scratches as the capillary tube detaches from the head.

Summary

Choosing the correct piercing tool and understanding its components are essential for efficient and high-quality seamless steel pipe production. Proper utilization and maintenance of the roller, guide, and head are key to achieving optimal deformation, precise diameter control, and enhanced overall productivity.