Straight seam steel pipe procurement method:
1. Purchasing needs to understand the types of steel pipes
1) Divided by type: straight seam steel pipe, seamless steel pipe, spiral steel pipe, etc.
2) Classification of cross-section shapes of straight seam steel pipes: square pipe, rectangular pipe, elliptical pipe, flat ellipse pipe, semicircular pipe, etc.
2. Need to pay attention to:
In the early days of the steel pipe industry, there were more deceptive tricks, but now people are more proficient in this industry, so those methods can be recognized by our naked eyes.
1) The wall thickness of the steel pipe is not enough. Using the gate method, the mouth end of the steel pipe looks thicker with a hammer shield, but the original shape will be revealed by measuring with an instrument.
2) Straight seams are used as seamless steel pipes. The number of straight seam welds is less than one longitudinal weld. The whole steel pipe is polished with a machine, commonly known as polishing, which acts as seamless as if there is no gap.
3) There is still a more sophisticated method now that is a seamless steel pipe, which is also a thermally expanded steel pipe. After the expansion, there is a lead powder inside, and there are burn marks on the outside. The welds are also invisible. Many relatively large steel pipes are sold seamlessly using this type of steel pipe to seek large profits.
4) Circumferential welded seam steel pipes use polishing to act as a proxy for straight seam steel pipes.
The processing method of straight seam steel pipe:
Forging steel: a pressure processing method that uses the reciprocating impact of a forging hammer or the pressure of a press to change the blank into the shape and size we need.
Extrusion: It is a processing method in which the steel puts the metal in a closed extruder and applies pressure at one end to extrude the metal from a prescribed die hole to obtain a finished product with the same shape and size. It is mostly used to produce non-ferrous metal materials.
Rolling: A pressure processing method in which steel metal billets are passed through a gap between a pair of rotating rolls (various shapes), and the cross-section of the material is reduced due to the compression of the rolls and the length is increased.
Drawing steel: It is a processing method that draws rolled metal blanks (forms, tubes, products, etc.) through a die hole to reduce the cross-section and increase the length, which is mostly used for cold working.
Post time: Nov-03-2023