First, 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.
Second, the shoddy thick-walled seamless pipe is easy to fold up. Folding is a variety of fold lines formed on the surface of thick-walled seamless tubes
that tend to span the longitudinal direction of the product. The reason for the folding is because the inferior manufacturers pursue high efficiency, the amount of pressing is too large, and the ear is generated. When the next rolling is performed, the folding occurs, and the folded product is cracked after bending, and the strength of the thick-walled seamless pipe is greatly reduced. .
Third, the surface of the shoddy thick-walled seamless pipe is prone to scarring. There are two reasons for this: ①Inferior thick-walled seamless pipe material is uneven and has many impurities. ②Fake inferior material manufacturers guide equipment is simple, easy to stick steel, these impurities are easy to produce scars after biting into the roll.
Fourth, the surface of the shoddy thick-walled seamless pipe often has a pockmark phenomenon. The pockmark is caused by the irregular wear of the surface of the thick-walled seamless pipe due to the serious wear of the groove. Because of the inferior thick-walled thick-walled seamless pipe manufacturers to pursue profits, often the most rolling groove rolling is exceeded.
5. The composition of the high-quality thick-walled seamless pipe is uniform, the tonnage of the cold-shearing machine is high, the end face of the cutting head is smooth and tidy, and the fake inferior material is often poor in material, and the end face of the cutting head often has a phenomenon of falling meat, that is, unevenness, and no Metallic luster.