Procurement method of straight seam steel pipe
1. Purchasing needs to know the type of steel pipe
1) By type: straight seam steel pipe, seamless steel pipe, spiral steel pipe, etc.
2) Section shape classification of straight seam steel pipe classification: square pipe, rectangular pipe, oval pipe, flat oval pipe, semicircular pipe, etc.
1) The wall thickness of the steel pipe is not enough to use the gate method. If the mouth end of the steel pipe is shielded with a hammer, it looks thicker, but it will be revealed when measured with an instrument.
2) Use a straight seam as a seamless steel pipe. There are fewer straight seams and only one longitudinal seam. The whole steel pipe is polished by a machine, commonly known as polishing, and it looks like there is no gap to act as a seamless pipe.
3) Now there is a more clever method is seamless steel pipe, seamless steel pipe is thermal expansion steel pipe. After the expansion, there is a lead powder inside, there are traces of burning on the outside, and the weld seam cannot be seen. Many relatively large steel pipes are sold as seamless steel pipes, seeking large profits.
4) Girth weld straight seam steel pipe uses polishing as a proxy for straight seam steel pipe.
The processing method of straight seam steel pipe:
Forging steel: a pressure processing method that uses the reciprocating impact force 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 for steel to place metal in a closed extrusion box and apply pressure at one end to make the metal extrude from the specified die hole to obtain a finished product with the same shape and size. It is mostly used for the production of non-ferrous metal steel.
Rolling: A pressure processing method in which the steel metal billet passes through the gap between a pair of rotating rolls (various shapes), and the cross-section of the material is reduced and the length is increased due to the compression of the rolls.
Pulling steel: It is a processing method in which the rolled metal blank (type, pipe, product, etc.) is pulled through the die hole to reduce the cross-section and increase the length. Most of them are used for cold work.