Thick-walled steel pipe production steps and the phenomenon of inferior steel pipes

Thick walled steel pipes: Steel pipes with an outer diameter to wall thickness ratio less than 20 are called thick walled steel pipes. It is mainly used for drilling pipes in petroleum geology, cracking pipes in the petrochemical industry, boiler steel pipes, bearing steel pipes, and high-precision structural steel pipes for automobiles, tractors, etc.
 
The significant difference between thick walled steel pipes and thin-walled steel pipes is the thickness of the steel pipe wall. Generally speaking, thin-walled steel pipes use cold drawing techniques, while thick walled steel pipes typically use hot rolling techniques. If they are distinguished by measurement units, it is generally believed that a wall thickness/steel pipe diameter equal to 0.02 is the dividing line between thick walled steel pipes and thin-walled steel pipes. Steel pipes with a wall thickness/diameter less than 0.02 are thin-walled, while steel pipes with a wall thickness/diameter greater than 0.02 are thick walled. In terms of usage, thin-walled steel pipe wall pipes are mostly used for steel pipes. Thick walled steel pipes are mainly used as blanks for hollow parts. Used for pressure and important steel pipes.
 

Thick walled steel pipes are mainly used in water supply projects, petrochemical industry, chemical industry, power industry, agricultural irrigation, and urban construction. Used for liquid transportation: water supply and drainage. Used for gas transportation: coal gas, steam, liquefied petroleum gas. For structural purposes: stacking steel pipes, bridges; Steel pipes for docks, roads, building structures, etc

The phenomenon of counterfeit thick walled steel pipes:
1. False and lower wall steel pipes are prone to folding.
2. False thick walled steel pipes usually have dents on the surface.
3. The surface of fake thick walled steel pipes is prone to scars.
4. The surface of fake and inferior materials is prone to cracking.
5. Fake thick walled steel pipes are easy to scratch.
6. False thick walled steel pipes lack metallic luster, are light red or similar in color to pig iron.
7. The transverse ribs of pseudo thick walled steel pipes are thin and low, and they are often insufficiently filled.
The cross-section of the fake thick walled steel pipe is elliptical.
10. The material of fake thick walled steel pipes contains many impurities, and the density of the steel is relatively low.
11. The inner diameter of the fake thick walled steel pipe fluctuates greatly.
12. The trademark and printing of steel pipes are relatively standardized.
13. For the large threads of three steel pipes with a diameter of 16 or more, the distance between the two trademarks exceeds 1M.
14. The longitudinal bars of counterfeit steel bars are usually wavy in shape.
15. The manufacturer of fake and lower wall steel pipes did not operate, resulting in loose packaging. The side profile is elliptical.
 
Production steps for thick walled steel pipes:
1. The stainless steel elbow changes the wall thickness of the thick walled steel pipe, thereby altering the wall thickness along the length of the steel pipe;
2. Process the square steel pipe section, then change the circular section to a square, elliptical, or polygonal shape;
3. Square steel pipes with curling and bottom sealing, curled to the outside or inside of the pipe to increase the total strength of the pipe end or seal the end of the square steel pipe;
4. Stainless steel elbow diameter square steel pipe, which means that the diameter of the steel pipe end or some parts of the steel pipe are reduced;
5. Stainless steel elbow is used to bend square steel pipes. The most common contact is to turn straight steel pipes into bends with different curvature radii, such as elbows, bent steel pipes, etc.
6. Square steel pipes with flanges and circular edges. The former refers to the end of a convex pipe pointing inward or outward, while the latter refers to a square steel pipe with protrusions or grooves formed in the circumferential direction of the pipe.