The structure is folded with a seamless steel pipe which is a variety of fold lines formed on the surface of the steel pipe, and such defects often extend throughout the longitudinal direction of the product. The reason for the folding is that the inferior manufacturer pursues high efficiency, the amount of pressing is too large, and the ear is generated, and the next rolling causes folding, and the folded product is cracked after being bent, and the strength of the steel is greatly reduced.
The pockmark is a defect caused by the irregularity of the surface of the steel due to the serious wear of the groove. Due to the pursuit of profit by shoddy steel pipe manufacturers, the most frequent rolling mill rolling is exceeded.
The surface of the fake steel pipe is prone to scarring. There are two reasons for this:
(1). The material of the fake steel pipe is uneven and has many impurities.
(2). The factory equipment of the fake and inferior steel pipe manufacturers is simple and easy to stick steel. These impurities are easy to cause crusting after biting the rolls.
The surface of the fake inferior material is prone to cracks because the billet is adobe, the adobe has many pores, and the adobe is cracked by the action of thermal stress during the cooling process, and there is crack after rolling.
Fake and inferior steel pipes are easy to scratch, because the equipment of the fake and inferior steel pipe manufacturers is simple, easy to produce burrs and scratch the surface of the steel. Deep scratches reduce the strength of the steel.
For more info, you may refer to: https://www.permanentsteel.com/product/carbon-steel-pipe.html
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