Technical of big diameter submerged arc welding pipe

Make big straight seam submerged arc welding pipe with large diameter seamless steel tube with UOE forming method displayed, row roller molding in (CFE), CE, etc. At the end of the procedure modeling method for the vast majority are on again after welding tube billet thermal expanding, in order to improve the quality of welded tube. Become a big hole diameter straight seam welded steel pipe production an important working procedure, to ensure the quality of the finished tube in the process is often referred to as thermal expansion of steel pipe.

Steel tube expander is a way of using hydraulic or mechanical outward from the steel tube wall strength make steel tube along the radial dilation forming pressure processing technology. Mechanical way than hydraulic way, the equipment is simple and more efficient, in the world's most advanced several big straight seam welding control pipe expanding process is adopted, the cangzhou thermal expansion of steel tube is to deal with some special engineering to deal with processing design production, its process is:

Mechanical expanding use of expanding machine end fan-shaped dollop of split along the radial expansion, the tube billet along the length direction in step by step manner, segmented realize the full length of the plastic deformation process. Is divided into five stages

1. The preliminary round stage. Fan open until all the fan-shaped blocks are in contact with the steel tube wall, the step length within the scope of steel pipe at various points in the circular tube radius size are almost unanimously, get a preliminary round mild steel pipe.

2. The phase of nominal diameter. Fan block from the front position began to reduce the movement speed, until arrived at required position, the position is the quality requirements of the finished pipe circumferential position.

3. Play after compensation phase. Fan block in the position of the two phase will further lower speed, to require position, this position is the process design requirements of the complex steel pipe circumferential position before.

4. Pressure maintaining stable stage. Fan piece of steel pipe circumferential position before playing after keeping a period of time, this is a requirement for equipment and carbon steel pipe expanding process pressure maintaining stable stage.

5. Unloading regression phase. Fan block from the complex steel pipe before the internal circumferential position began to bounce back quickly, until arrived at the location of the initial hole diameter, it is expanding the fan-shaped dollop of technical requirement minimum contraction diameter.

In practical applications, the process simplified, 2, 3 steps can be combined to simplify, this has no effect on the quality of steel pipe hole enlargement.

Hunan great steel pipe co.,ltd could supply good quality big diameter submerged arc welding pipe.