Views: 2 Author: Site Editor Publish Time: 2018-05-15 Origin: Site
The specifications of seamless precision steel pipes are generally represented by the outer diameter and thickness. For example, a steel pipe with an outer diameter of 217mm and a wall thickness of 13mm is marked with φ217*13mm. Seamless steel pipe specifications are achieved by expanding the diameter. Let's take a look at the diameter expansion technology of the 16mn precision seamless steel pipe.
The expansion of the 16mn seamless steel pipe is a pressure processing technology that uses hydraulic or mechanical force to force the pipe to expand outwardly in the radial direction from the inner wall of the seamless pipe. The mechanical method is simpler and more efficient than the hydraulic method. Generally, the outer diameter of the steel pipe is expanded mechanically. The specific process is:
1. Initial rounding stage: The sector block is opened until all sectors come into contact with the inner wall of the steel tube. At this time, the radius of each point in the inner tube of the 16mn seamless steel tube in the step length range is almost the same, and the steel tube is initially rounded.
2. Nominal inner diameter stage: The sector begins to reduce the speed of movement from the front until it reaches the desired position, which is the quality of the finished pipe circumference.
3. The elastic compensation stage: The sector block begins to further reduce the speed in the second stage until it reaches the required position. This position is the position of the inner circumference of the steel pipe before the rebound of the process design.
4. The pressure-stabilization phase: The fan-shaped block is re-elasticated and the inner circumferential position of the steel pipe remains stationary for a certain period of time. This is the stable pressure-keeping phase of equipment and expansion requirements.
5. Unloading Regression Stage: The sector block rapidly retracts from the inner circumferential position of the steel pipe before rebound, until reaching the initial expansion position, which is the minimum shrinkage diameter of the sector block required by the expanding process.
Theoretically speaking, the expansion of the 16mn precision seamless steel pipe is to use the segmented segment of the expander to expand radially, so that the pipe blank can be formed in a stepwise manner in the length direction to achieve full pipe length deformation. However, the operation requires a relatively high technical requirement, so it is very important to carry out each processing step for the 16mn precision seamless pipe.