How to identify fake and inferior thick-walled seamless steel pipes?

How to identify fake and inferior thick-walled seamless steel pipes? Counterfeit and inferior steel pipes will not only cause economic losses to the enterprise, but will also cause unqualified engineering quality and cause danger to personal safety. Therefore, it has become an inevitable technology to master the identification method of counterfeit and inferior thick-walled seamless steel pipes.

1. Fake and inferior thick-walled seamless steel pipes (smls pipe) are easy to fold. Folding is a variety of fold lines formed on the surface of thick-walled seamless steel pipes, and this defect often runs through the longitudinal direction of the entire product. The reason for folding is due to the pursuit of high efficiency by fake and inferior manufacturers, and the amount of reduction is too large, resulting in ears, and folding occurs during the next rolling. The folded product will crack after bending, and the strength of the thick-walled seamless steel pipe will be greatly reduced. 

2. Fake thick-walled seamless steel pipes often have pitting on the surface. The pitted surface is a defect of irregular roughness on the surface of the thick-walled seamless steel pipe due to severe wear of the rolling groove. As manufacturers of counterfeit and inferior thick-walled seamless steel pipes are pursuing profits, the groove rolling often exceeds the standard.

　　
3. Fake thick-walled seamless steel pipes are prone to scars on the surface. There are two reasons: 1. Fake thick-walled seamless steel pipes are uneven in material and have many impurities. 2. The guide and guard equipment of the counterfeit steel manufacturers is simple and easy to stick to the steel. These impurities will easily cause scars after biting the roll.
　　
4. The surface of the fake and inferior material is prone to cracks, because its billet is adobe, and the adobe has many pores. The adobe is subjected to thermal stress during the cooling process, causing cracks, and there will be cracks after rolling.

5. Fake and inferior thick-walled seamless steel pipes are easy to scratch. The reason is that the equipment of fake and inferior materials manufacturers is simple and easy to produce burrs and scratch the surface of thick-walled seamless steel pipes. Deep scratches reduce the strength of thick-walled seamless steel pipes.
　　
6. Fake thick-walled seamless steel pipes have no metallic luster and are light red or pig-iron-like color. There are two reasons for it. Its blank is adobe. The rolling temperature of fake and inferior materials is not standard, and their steel temperature is visually inspected, so that it cannot be rolled according to the specified austenite area, and the performance of thick-walled seamless steel pipes naturally fails to meet the standard.
　　
7. The cross ribs of fake thick-walled seamless steel pipes are thin and low, and often appear dissatisfied. The reason is that in order to achieve large negative tolerances, the reduction of the first few passes of the finished product is too large, the iron type is too small, and the hole type is filled. dissatisfied.
　　
8. The cross-section of the fake thick-walled seamless steel pipe is elliptical. The reason is that in order to save material, the reduction amount of the first two passes of the finished roll is too large. The strength of this kind of rebar is greatly reduced, and it does not conform to rebar. The standard of external dimensions.
　　
9. The composition of high-quality thick-walled seamless steel pipes is uniform, the tonnage of the cold shearing machine is high, and the end face of the cutting head is smooth and tidy. However, due to the poor material, the end face of the cutting head often has the phenomenon of meat loss, that is, uneven, and no Metallic luster. Moreover, because the products of fake and inferior materials manufacturers have fewer cuts, big ears will appear at the beginning and the end.
 

10. The material of fake thick-walled seamless steel pipe contains many impurities, the density of the steel is too small, and the size is severely 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%. When the length is 9M, its single theoretical weight is 120 kg, and its minimum weight should be: 120 *(l-5%)=114 Kilogram, the actual weight of a single piece weighed out is smaller than 114 kg, it is a fake thick-walled seamless steel pipe, because its negative tolerance exceeds 5%. Generally speaking, the effect of phasing weighing will be better, mainly considering the problem of cumulative error and probability theory.

Eastern Steel Manufacturing Co.,Ltd is a leading manufacturer and distributor of seamless steel pipe(carbon seamless line pipe/seamless boiler tube/seamless galvanized pipe/hydraulic steel tube), welded steel pipe, OCTG products and fittings. We supply first-step processing, semi-finished parts and finished parts to help our clients meet fabrication requirements beyond their capacity or to improve operations by moving forward the pre-production processing.

Article source: https://article-realm.com/article/Finance/17797-How-to-identify-fake-and-inferior-thick-walled-seamless-steel-pipes.html