How To Identify Fake Thick-walled Seamless Square Tubes

1. Fake and inferior thick-walled seamless steel pipes are prone to folding. Folds are various fold lines formed on the surface of thick-walled seamless steel pipes. This defect often runs throughout the longitudinal direction of the product. The folding is because shoddy manufacturers pursue high efficiency and the reduction is too large. Folding occurs during the next rolling step. The folded product will crack after bending, and the strength of the thick-walled seamless steel pipe is greatly reduced.

2. Fake thick-walled seamless steel pipes often have pitted surfaces on the surface. Pockmarking is an irregular uneven defect on the surface of thick-walled seamless steel pipes caused by severe groove wear. 

3. The surface of fake thick-walled seamless steel pipes is prone to scarring. There are two reasons: ① The material of fake and inferior thick-walled seamless steel pipes is uneven and contains many impurities. ② The guide equipment of fake and inferior material manufacturers is simple and easy to stick to steel. These impurities can easily cause scarring after biting the rollers.

4. The surface of fake and inferior materials is prone to cracks because its raw material is adobe, which has many pores. The adobe is subject to thermal stress during the cooling process, causing cracks, and cracks appear after rolling.

5. Square and rectangular tubes tell us that fake and inferior thick-walled seamless steel pipes are easy to scratch. The reason is that the equipment of the fake and inferior material manufacturers is simple and easy to produce burrs, which can scratch the surface of thick-walled seamless steel pipes. Deep scratches reduce the strength of thick-walled seamless steel pipes.

6. The fake thick-walled seamless steel pipe has no metallic luster and is light red or similar in color to pig iron. There are two reasons: ① Its blank is adobe. ② The rolling temperature of fake and inferior steel pipes is not standard. Their steel temperature is measured by visual inspection. This makes it impossible to roll according to the specified austenite area. Naturally, the performance of thick-walled seamless steel pipes cannot meet the standards.

7. Seamless square tube tells the story about the thin and low transverse ribs of fake and inferior thick-walled seamless steel tubes, which often appear to be underfilled. The reason is that to achieve a large negative tolerance, the reduction amount of the first few passes of the finished product is too large and the iron shape is biased. 

8. The cross-section of the fake thick-walled seamless steel pipe is oval. The reason is that to save materials, the manufacturer has a larger reduction amount in the first two passes of the finished roller. The strength of this kind of steel pipe is greatly reduced, and it does not meet the external dimensions standard.

9. The manufacturer of special-shaped pipes said that high-quality thick-walled seamless steel pipes have uniform composition, the tonnage of the cold shear machine is high, and the cut end face is smooth and neat. However, due to the poor material quality of fake and inferior materials, the cut-end face often has the phenomenon of flesh loss, that is, unevenness. 

10. The material of fake and inferior thick-walled seamless steel pipes contains many impurities, the density of the steel is small, and the size is seriously out of tolerance, so it can be weighed and checked without a vernier caliper.