1. The surface of inferior seamless pipes is prone to scarring.
Mainly due to two reasons:
(1) Inferior seamless steel pipes have more impurities and uneven materials.
(2) The guides and guards of inferior pipe manufacturers are poorly equipped, and are particularly prone to sticking to steel. The pipes containing impurities are prone to scarring after being bitten into the rolled spokes.
2. Inferior seamless steel pipes are prone to pipe folding.
The so-called folding refers to the various fold lines formed on the surface of the seamless steel pipe, and this defect often runs through the longitudinal direction of the entire product. The reason for the folding is that the manufacturer pursues high efficiency in order to increase the output, and the reduction in the production process is too large, resulting in ears, which are prone to folding in the next rolling process. The folded product is easy to crack after being bent, which greatly reduces the strength of the pipe.
3. Inferior seamless steel pipes are prone to scratches. The reason is that inferior steel pipe manufacturers have poor production equipment, and the products are prone to burrs, scratching the surface of the steel, and deep scratches will reduce the strength of the steel.
4. The surface of inferior seamless steel pipes often has pockmarks. Pockmarked surface is a defect of irregular unevenness on the surface of the steel due to severe wear of the rolling groove. Because manufacturers of inferior steel pipes want to pursue profits, groove rolling often exceeds the standard.
5. The surface of poor-quality pipes is prone to cracks. One of the reasons is that its bad material is soil damage.
6. Inferior seamless steel pipes have no metallic luster and are light red or similar in color to pig iron. There are two reasons:
(1) Its bad material is adobe.
(2) The rolling temperature of inferior materials is not standard, and their steel temperature is measured visually, so that rolling cannot be carried out according to the specified austenite region, and the performance of the steel cannot meet the standard naturally.
7. The horizontal ribs of inferior seamless steel pipes are thin and low, and often appear to be full and dissatisfied. The reason is that in order to achieve a large negative tolerance, the reduction in the first few passes of the finished product is too large, the iron shape is too small, and the pass is not full.
8. The composition of high-quality steel is uniform, the specification of the pipe cutting machine is high, and the end face of the cutting head is smooth and neat, while the end face of the cutting head is often uneven and has no metallic luster due to the poor quality of the material. Moreover, because the products of inferior material manufacturers have fewer heads, big ears will appear at the head and tail.
9, the cross-section of inferior seamless steel pipe is irregular, and the ellipticity error is large. The reason is that in order to increase the production, the reduction amount of the first two passes of the finished product is too large, the strength of this seamless steel pipe is greatly reduced, and it does not meet the standard for the outer dimension of the seamless steel pipe.
10. The material of inferior seamless steel pipe contains many impurities, the density of the steel is relatively small, and the size is seriously out of tolerance, so it can be weighed and checked without a vernier caliper.
11. The inner diameter of the inferior non-glare steel pipe fluctuates greatly because of;
(1) The steel temperature is unstable and has yin and yang sides.
(2) The composition of the steel is uneven.
(3) Due to poor equipment, low foundation strength, and large bouncing of the milking machine, there will be large changes in the same week. Such seamless steel pipes are prone to breakage due to uneven stress.
12. The trademarks and printing of high-quality seamless steel pipes are relatively standardized.
13. Manufacturers of inferior seamless steel pipes pack loosely. The sides are relatively round.
Mainly due to two reasons:
(1) Inferior seamless steel pipes have more impurities and uneven materials.
(2) The guides and guards of inferior pipe manufacturers are poorly equipped, and are particularly prone to sticking to steel. The pipes containing impurities are prone to scarring after being bitten into the rolled spokes.
2. Inferior seamless steel pipes are prone to pipe folding.
The so-called folding refers to the various fold lines formed on the surface of the seamless steel pipe, and this defect often runs through the longitudinal direction of the entire product. The reason for the folding is that the manufacturer pursues high efficiency in order to increase the output, and the reduction in the production process is too large, resulting in ears, which are prone to folding in the next rolling process. The folded product is easy to crack after being bent, which greatly reduces the strength of the pipe.
3. Inferior seamless steel pipes are prone to scratches. The reason is that inferior steel pipe manufacturers have poor production equipment, and the products are prone to burrs, scratching the surface of the steel, and deep scratches will reduce the strength of the steel.
4. The surface of inferior seamless steel pipes often has pockmarks. Pockmarked surface is a defect of irregular unevenness on the surface of the steel due to severe wear of the rolling groove. Because manufacturers of inferior steel pipes want to pursue profits, groove rolling often exceeds the standard.
5. The surface of poor-quality pipes is prone to cracks. One of the reasons is that its bad material is soil damage.
6. Inferior seamless steel pipes have no metallic luster and are light red or similar in color to pig iron. There are two reasons:
(1) Its bad material is adobe.
(2) The rolling temperature of inferior materials is not standard, and their steel temperature is measured visually, so that rolling cannot be carried out according to the specified austenite region, and the performance of the steel cannot meet the standard naturally.
7. The horizontal ribs of inferior seamless steel pipes are thin and low, and often appear to be full and dissatisfied. The reason is that in order to achieve a large negative tolerance, the reduction in the first few passes of the finished product is too large, the iron shape is too small, and the pass is not full.
8. The composition of high-quality steel is uniform, the specification of the pipe cutting machine is high, and the end face of the cutting head is smooth and neat, while the end face of the cutting head is often uneven and has no metallic luster due to the poor quality of the material. Moreover, because the products of inferior material manufacturers have fewer heads, big ears will appear at the head and tail.
9, the cross-section of inferior seamless steel pipe is irregular, and the ellipticity error is large. The reason is that in order to increase the production, the reduction amount of the first two passes of the finished product is too large, the strength of this seamless steel pipe is greatly reduced, and it does not meet the standard for the outer dimension of the seamless steel pipe.
10. The material of inferior seamless steel pipe contains many impurities, the density of the steel is relatively small, and the size is seriously out of tolerance, so it can be weighed and checked without a vernier caliper.
11. The inner diameter of the inferior non-glare steel pipe fluctuates greatly because of;
(1) The steel temperature is unstable and has yin and yang sides.
(2) The composition of the steel is uneven.
(3) Due to poor equipment, low foundation strength, and large bouncing of the milking machine, there will be large changes in the same week. Such seamless steel pipes are prone to breakage due to uneven stress.
12. The trademarks and printing of high-quality seamless steel pipes are relatively standardized.
13. Manufacturers of inferior seamless steel pipes pack loosely. The sides are relatively round.
