How to flare stainless steel round tube

The expansion is actually a pressure process that uses hydraulic or mechanical means to release a certain force on the inside of the pipe, so that the metal pipe expands outward along the axial direction. The mechanical method is simpler and more efficient than the hydraulic method, so it is more commonly used in actual applications, especially in very large diameter stainless steel pipes. Generally speaking, the process of expanding and reducing the diameter of stainless steel pipes can be mainly divided into five stages.
Expansion stage
1. Basic rounding stage
The fan-shaped blocks are opened until all the fan-shaped blocks touch the inner cavity of the steel pipe. At this time, the radius of each point in the stride range, the steel pipe, and the round steel pipe is basically the same, and the stainless steel round pipe is basically round.
2. Inner diameter stage
The fan-shaped block gradually reduces the movement speed in the past section until it reaches the specified position, which is the upper circle position of the finished pipe with quality requirements.
3. Rebound compensation stage
In other words, the fan-shaped block of the stainless steel welded pipe can be reduced slowly and quickly until it reaches the specified position, which is the position on the inner circle of the steel pipe before rebounding required by the process technology.
4. Pressure-maintaining and stabilizing stage
The fan-shaped block remains stationary for a period of time on the inner circle of the pipe before rebounding. This is the pressure-maintaining and stabilizing stage required by the equipment and the expansion process.
5. Pressure relief and return stage
At this time, the fan-shaped block continues to shrink from the upper circle of the stainless steel pipe before rebounding, and will eventually reach the original expanded position, which is the minimum contraction diameter of the fan-shaped block required by the expansion process. In actual application, in the process simplification, the 2nd and 3rd steps can be combined and simplified, which has no effect on the expansion quality.
How to expand the stainless steel round pipe is a forming process to expand the diameter of the end of the stainless steel round pipe. The expansion shape can be conical or cylindrical. The tube blank enters the deformation zone under the action of axial force, and the expansion plastic deformation of tangential stretching occurs in the deformation zone, and then enters the stable deformation zone and finally forms.