CS seamless pipe is a steel pipe that is perforated by the whole round steel and has no weld seam on the surface. According to its production process, it can be divided into cold-drawn seamless pipe, hot-rolled seamless pipe, extruded pipe, pipe jacking, etc., all of which have their own process regulations. Widely used in pipelines for transporting oil, natural gas, gas, water and certain solid materials.

With the popularization and application of cs seamless pipes in the construction industry, its quality is prone to problems, so how to distinguish the fake and inferior cs seamless pipes?

1. Fake and inferior cs seamless pipes are prone to folding
 
Folding is a variety of fold lines formed on the surface of cs seamless pipes, and this defect often runs through the longitudinal direction of the entire product. The reason for the folding is that the fake and inferior manufacturers pursue high efficiency, and the reduction is too large, resulting in ears. Folding will occur in the next rolling process. The folded product will crack after bending, and the strength of the wall seamless pipe will drop greatly.

2. The appearance of fake and inferior cs seamless pipes often has pockmarks
 
Pockmarked surface is a defect of irregular unevenness on the surface of cs seamless pipe caused by serious wear of the rolling groove. Because manufacturers of fake and inferior cs seamless pipes want to pursue profits, the exceeding standard of groove rolling often occurs.

3. The surface of fake and inferior cs seamless pipes is prone to scars. There are two reasons for the scars: first, the fake pipe is made of uneven material with too many impurities; second, the inferior equipment is easy to stick to steel, and when some impurities enter the machine, it will leave scars on the surface of the seamless pipe.

4. Cracks are easy to occur on the surface of fake and inferior cs seamless pipes. The reason is that its billet is adobe, and the adobe has many pores. During the cooling process, due to the effect of thermal stress, cracks are generated, and cracks are formed after rolling.

5. Fake and inferior cs seamless pipes are easy to scratch. The reason is that the equipment of the fake and inferior cs seamless pipe manufacturers is simple and easy to produce burrs and scratch the surface of cs seamless pipes. Deep scratches reduce the strength of cs seamless pipe.

6. Fake and inferior cs seamless pipes have no metallic luster and are light red or similar to pig iron. The main reason is that the rolling temperature is not standard, and the temperature of these pipes is measured manually instead of mechanically, so rolling in the austenite zone cannot be carried out, and the performance is not up to standard.

7. The cross-section of fake and inferior cs seamless pipes is oval. In order to save materials, some manufacturers deliberately increase the amount of rolling reduction, resulting in a decrease in strength, which cannot meet the size requirements of cs seamless pipes.

8. The diameter error of fake and inferior cs seamless pipes is relatively large. There are three reasons for this phenomenon: first, the temperature of molten steel is unstable; second, the composition of molten steel is uneven; third, the equipment lags behind and the rolling mill bounces greatly. For these reasons, the inner diameter of the steel pipe becomes larger, the stress is uneven, and it is easy to break.

9. The composition of the high-quality cs seamless pipe is uniform, the tonnage of the cold shearing machine is high, and the end face of the cutting head is smooth and neat. However, due to the poor quality of fake and inferior materials, the end face of the cutting head often has the phenomenon of meat loss, that is, it is uneven and has no metallic luster. Moreover, because the products of fake and inferior cs seamless pipe manufacturers have fewer heads, big ears will appear at the head and tail.

10. The material of fake and inferior cs seamless pipes contains many impurities, the density of steel is relatively small, and the size is seriously out of tolerance, so it can be weighed and checked without a vernier caliper. For example, for rebar 20, the national standard stipulates that the maximum negative tolerance is 5%, and its single theoretical weight is 120 kg when the length is 9M. Its minimum weight should be: 120 X (l-5%) = 114 kg, and the actual weight of a single piece weighed out is less than 114 kg, which is a fake and inferior cs seamless pipe.