Galvanized steel pipe products are not only rich in variety, but also have various processing processes and molding methods. In most cases, the last process after molding is to expand the full length of the welded pipeline to improve the quality of the welded pipe. In other words, the expansion process has become an important process for ensuring the quality of finished pipes in galvanized steel pipes. The so -called expansion is actually a pressure processing process. The method of hydraulic or mechanical method is used to apply a certain force inside the steel pipe to make the radial diameter of the steel pipe. Machinery methods are simpler and efficient than hydraulic methods, so it is more common in practical applications.
Generally speaking, in the process of galvanized steel pipe products, it can be divided into five stages.
The first is the initial round stage: open the fan -shaped block until all the fan -shaped blocks are in contact with the inner wall of the steel pipe. At this time, the radius of each point in the steel pipe in the staircase range was almost the same, and the steel pipe was rounded up.
The second is the nominal inner diameter stage: the segmented block starts to slow down from the front position, until the location of the requirements, that is, the inner circular position of the finished product tube of the quality requirements.
The third stage is called a rebound compensation phase, that is, the speed of the galvanized steel fan -shaped block will gradually decrease until it reaches the required position, that is, the internal circular weekly position of the steel pipe before the rebound needs to be designed through the process.
Fourth, stabilize stabilization stage: Before the fan -shaped block rebounds, the inside of the steel pipe is kept quiet for a period of time. This is a stable and stable stress stage required for the equipment and expansion process.
The last stage is called uninstallation and regression. At this time, the fan -shaped block continued to shrink back from the circular position of the galvanized steel pipe until it finally reached the initial swelling position, which is the minimum shrinkage of the fan -shaped block. Expansion process. In practical applications, when the process is simplified, the step 2 and step 3 can be merged and simplified, which has no effect on the quality of the tube expansion.
