First, procurement methods of straight seam steel pipes: Procurement is a relatively lucrative industry, but it is quite difficult to do. They also bear a lot of hardships. Many things have never been seen before in the project, and they also need to be studied and researched. Here are a few points that should be paid attention to when purchasing straight seam steel pipes.
1. Procurement requires an understanding of the types of steel pipes
1) According to the type: straight seam steel pipes, seamless steel pipes, spiral steel pipes, etc.
2) Classification of straight seam steel pipes by cross-sectional shape: square pipes, rectangular pipes, elliptical pipes, flat elliptical pipes, semicircular pipes, etc.
2. Note: There were many tricks to deceive people in the early days of the steel pipe industry, but now people are more proficient in this industry, so those means can be identified with our naked eyes
1) If the wall thickness of the steel pipe is not enough, use the gate method. The mouth of the steel pipe is hammered with a shield to make it look thicker, but it will be exposed when measured with an instrument.
2) Use straight seams as seamless steel pipes. There are relatively few straight seams, only one longitudinal weld. Use a machine to grind the entire steel pipe, commonly known as polishing, so that it looks like there is no gap and acts as seamless.
3) Now there is another more sophisticated method, which is seamless steel pipes. Seamless steel pipes are also hot-expanded steel pipes. After expansion, there is lead powder inside, and there are traces of burning on the outside, and the welds cannot be seen. Many larger steel pipes use this kind of steel pipe as seamless to sell, seeking large profits.
4) Girth weld straight seam steel pipes use polishing to replace straight seam steel pipes.
Second, the processing method of straight seam steel pipes:
Forging steel: a pressure processing method that uses the reciprocating impact force of the forging hammer or the pressure of the press to change the blank into the shape and size we need.
Extrusion: It is a processing method in which steel puts metal in a closed extrusion cylinder, applies pressure at one end, and squeezes the metal out of the specified die hole to obtain a finished product with the same shape and size. It is mostly used to produce non-ferrous metal steel.
Rolling: A pressure processing method in which a steel metal billet is passed through the gap between a pair of rotating rollers (various shapes). Due to the compression of the rollers, the material cross-section is reduced and the length is increased.
Drawing steel: A processing method in which the rolled metal billet (profile, tube, product, etc.) is drawn through a die hole to reduce the cross-section and increase the length. Most of them are used for cold processing.
Post time: Jan-03-2025