How to distinguish fake and inferior steel in appearance

1. Fake and inferior steel is prone to folding. Folding is a variety of fold lines formed on the surface of steel, and this kind of defect often runs through the longitudinal direction of the entire product. The reason for the folding is that the counterfeit manufacturers are pursuing high efficiency, the amount of reduction is too large, and the ears are generated. The folding will occur during the next rolling. The folded product will crack after bending, and the strength of the steel will be greatly reduced. 　　

2. The appearance of fake and inferior steel is often pitted. The pitted surface is a defect of irregular unevenness on the surface of the steel due to severe wear of the rolling groove. As the counterfeit and inferior steel manufacturers are pursuing profits, the groove rolling often exceeds the standard; 　　

3. The surface of fake and inferior steel is prone to scars. There are two reasons 　　

(1) The material of fake and inferior steel is uneven and there are many impurities; 　　

(2) The guide and guard equipment of the fake and inferior material 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, resulting in cracks, and there will be cracks after rolling.　　

5. Fake and inferior steel is easy to scratch because of the simple equipment of manufacturers of fake and inferior materials, which can easily produce burrs and scratch the surface of steel. Deep scratches reduce the strength of steel. (Guide: Fireproof properties of steel structure)

6. The fake and inferior steel has no metallic luster, and is pale red or pig-iron-like color. There are two reasons: one is that its blank is adobe. The second is that the rolling temperature of fake and inferior materials is not standard. Their steel temperature is visually inspected. In this way, rolling cannot be carried out in the specified austenite area, and the performance of the steel will naturally not meet the standard.　　

7. The cross ribs of counterfeit steel are thin and low, and the phenomenon of dissatisfaction often occurs. The reason is that in order to achieve a large negative tolerance, 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 not full.　　

8. The cross-section of the counterfeit steel is elliptical. The reason is that in order to save material, the reduction 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 meet the standard of the shape of rebar.　　

9. The composition of high-quality steel is uniform, the tonnage of the cold shear is high, and the end face of the cutting head is smooth and tidy. However, due to the poor quality of the fake material, 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 the fake and inferior material manufacturers have fewer cuts, big ears will appear at the beginning and the end.　　

10. The fake and inferior steel material contains many impurities, the density of the steel is 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 fixed length is 9M, its single theoretical weight is 120 kg. Its minimum weight should be: 120X (l-5%) u003d 114 kg, The actual weight of a single piece weighed out is less than 114 kg, which is a fake and inferior steel 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.　　

11. The inner diameter size of fake and inferior steel fluctuates greatly, the reason is: 　　

(1) Unstable steel temperature has a yin and yang side; 　　

(2) The composition of steel is not uniform; 　　

(3) Due to the simple equipment and low foundation strength, the rolling mill bounces greatly. There will be a large change in the inner diameter of the same week, so that the uneven force of the steel bar is prone to fracture.　　

12. The trademarks and printing of high-quality materials are relatively standardized.　　

13. 3. For large threads with a steel diameter of 16 or more, the distance between the two trademarks is above IM.　　

14. The longitudinal bars of shoddy steel rebar are often wavy.　　

15. The shoddy steel manufacturers are loosely packed because they have no driving vehicles. The side is oval.

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