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Performance Difference Between Seamless Pipes & Traditional Pipes
Dec 13, 2020
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This article tells about the performance difference between seamless steel pipes and traditional pipes.
Seamless steel pipes have hollow cross-section, which are widely used for transporting fluid, such as oil, natural gas, gas, water and some solid materials. Compared with solid steel such as round steel, the steel tube is lighter in weight when the bending and torsion strength is the same, so it is a kind of economical section steel.
What is seamless steel pipe?
The seamless steel pipe is not rare in our life, as long as we pay attention to it, we can see it all around such as hot water pipes, our bicycle frames and so on. The seamless steel pipe is widely used in construction, mechanical parts and other fields because of its light weight and the same bending and torsion strength. In China, the strength of the brand is very strong, so is the seamless steel pipe. What is the performance difference between seamless steel pipes and traditional pipes? Now let's take a look at the knowledge of the seamless steel pipe.
The seamless steel pipe has hollow cross-section, which is widely used for transporting fluid, such as oil, natural gas, gas, water and some solid materials. Compared with solid steel such as round steel, steel pipes are lighter in weight when bending and torsion strength is the same. It is a kind of economical section steel. It is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycle frames and steel scaffold used in construction. It can improve the utilization rate of materials, simplify the manufacturing process, and save materials and materials working hours, like rolling bearing rings and Jack sleeves, which have been widely used in steel pipes manufacturing.
Application
1. Seamless steel pipe is widely used. The seamless steel pipe for general use is rolled by common carbon structural steel, low alloy structural steel or alloy structural steel, with the largest output. It is mainly used as pipeline or structural parts for conveying fluid.
2. According to different uses, it can be divided into three types:
A. supply according to chemical composition and mechanical properties.
B. supply according to mechanical properties.
C. supply according to hydraulic test. If the steel pipes supplied according to a and B are used to bear liquid pressure, hydrostatic test shall also be conducted.
3. There are many kinds of seamless pipes for special applications, such as boiler seamless pipes, geological seamless pipes and petroleum seamless pipes.
Production process of seamless steel pipes
The production methods of seamless steel pipes can be roughly divided into cross rolling method (Mannesmann method) and extrusion method.
1. The method of cross rolling (Mannesmann method) is to pierce the damaged pipe with inclined roll, and then extend it by rolling mill. This method is fast in production, but has high requirements for the processability of tube blanks. It is mainly suitable for the production of carbon steel and low alloy steel pipe.
2. The extrusion method is that the tube blank or ingot is pierced by a piercer, and then extruded into a steel pipe by the extruder. This method has lower efficiency than the cross rolling method and it is suitable for producing high strength alloy steel pipes.
The tube billet or ingot must be heated before the cross rolling and extrusion methods. The steel pipe produced is called hot rolling pipe. The steel pipe produced by hot working method can be cold processed as required. There are two methods of cold working: one is cold drawing, which is to draw the steel pipe through the drawing pipe, so that the steel pipe gradually becomes thinner and longer; the other is cold rolling method, which applies the hot rolling mill invented by Mannesmann brothers in cold working. The cold working of seamless steel pipes can improve the dimensional accuracy and processing smoothness of seamless steel pipes, and improve the mechanical properties of materials.
1. Compared with other traditional pipes, seamless steel pipes have the advantages of light raw material, high strength, good resistance, high internal pressure, sensitive production and application, and it can be used to messy or harsh geological conditions.
2. However, there is a large rate of steel pipes in the process of application, mainly due to the trouble of internal and external anti-corrosion treatment. The first question of external anti-corrosion is very important, the quality of external anti-corrosion directly affects its service life. At present, the external anti-corrosion of domestic steel pipes is mainly: concealment method. All steel pipes are required to be reinforced or extra strengthened external corrosion protection, and cathodic protection is promoted in some areas. The hidden external anti-corrosion methods are usually coatings such as petroleum asphalt and epoxy coal tar pitch. The latter is not easy to solidify at low temperature, and there are more questions in the field welding joint construction. This chlorosulfonated polyethylene was used before, because most of the solvents are easy to produce pinholes, and the resistance to penetration is not up to standard. Some areas are clear about it and no longer used it. As for cathodic protection, its anti-corrosion effect is better, but because of the sacrificial anode method, the anode must be replaced regularly in future operation, which increases the operation cost and operation.
Besides, there are three methods for seamless steel pipes supply: anticorrosive coating, resin mortar and cement mortar. There are two questions in the three methods: the first is about the bond strength between anticorrosive coating and steel pipes, which has been mentioned before by cement mortar. As for anticorrosive coating and resin mortar, both the inner and outer surfaces of steel pipes are required to be completely derusted before construction, but it is difficult to achieve this point. Therefore, the rust spots will form the source of delamination in the future, forming corrosion and scaling. The second is that most of the steel pipes are butt welded on site, and anticorrosion is carried out after welding. It can only be done manually. The quality is not easy to control, and the pipe with smaller diameter is no longer anticorrosive because personnels can not enter the construction. It also forms the hidden danger of weld damage in the future.
According to the analysis of several pipe burst accidents, it is mainly caused by weld corrosion with low weld quality.
3. The cost of seamless steel pipe supply is high.
4. Poor hydraulic function and high energy consumption. The internal roughness coefficient of the steel pipe is between 0.013-0.014. Therefore, for the pipeline with the same water delivery capacity and equal pipe diameter, the resistance along the pipeline is high. The demand increases the pump head and the initial investment, and the operation cost increases greatly due to the large power consumption.
5. The pipeline has the disadvantage of poor bearing capacity to water hammer.
Seamless steel pipes have hollow cross-section, which are widely used for transporting fluid, such as oil, natural gas, gas, water and some solid materials. Compared with solid steel such as round steel, the steel tube is lighter in weight when the bending and torsion strength is the same, so it is a kind of economical section steel.
What is seamless steel pipe?
The seamless steel pipe is not rare in our life, as long as we pay attention to it, we can see it all around such as hot water pipes, our bicycle frames and so on. The seamless steel pipe is widely used in construction, mechanical parts and other fields because of its light weight and the same bending and torsion strength. In China, the strength of the brand is very strong, so is the seamless steel pipe. What is the performance difference between seamless steel pipes and traditional pipes? Now let's take a look at the knowledge of the seamless steel pipe.
The seamless steel pipe has hollow cross-section, which is widely used for transporting fluid, such as oil, natural gas, gas, water and some solid materials. Compared with solid steel such as round steel, steel pipes are lighter in weight when bending and torsion strength is the same. It is a kind of economical section steel. It is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycle frames and steel scaffold used in construction. It can improve the utilization rate of materials, simplify the manufacturing process, and save materials and materials working hours, like rolling bearing rings and Jack sleeves, which have been widely used in steel pipes manufacturing.
Application
1. Seamless steel pipe is widely used. The seamless steel pipe for general use is rolled by common carbon structural steel, low alloy structural steel or alloy structural steel, with the largest output. It is mainly used as pipeline or structural parts for conveying fluid.
2. According to different uses, it can be divided into three types:
A. supply according to chemical composition and mechanical properties.
B. supply according to mechanical properties.
C. supply according to hydraulic test. If the steel pipes supplied according to a and B are used to bear liquid pressure, hydrostatic test shall also be conducted.
3. There are many kinds of seamless pipes for special applications, such as boiler seamless pipes, geological seamless pipes and petroleum seamless pipes.
Production process of seamless steel pipes
The production methods of seamless steel pipes can be roughly divided into cross rolling method (Mannesmann method) and extrusion method.
1. The method of cross rolling (Mannesmann method) is to pierce the damaged pipe with inclined roll, and then extend it by rolling mill. This method is fast in production, but has high requirements for the processability of tube blanks. It is mainly suitable for the production of carbon steel and low alloy steel pipe.
2. The extrusion method is that the tube blank or ingot is pierced by a piercer, and then extruded into a steel pipe by the extruder. This method has lower efficiency than the cross rolling method and it is suitable for producing high strength alloy steel pipes.
The tube billet or ingot must be heated before the cross rolling and extrusion methods. The steel pipe produced is called hot rolling pipe. The steel pipe produced by hot working method can be cold processed as required. There are two methods of cold working: one is cold drawing, which is to draw the steel pipe through the drawing pipe, so that the steel pipe gradually becomes thinner and longer; the other is cold rolling method, which applies the hot rolling mill invented by Mannesmann brothers in cold working. The cold working of seamless steel pipes can improve the dimensional accuracy and processing smoothness of seamless steel pipes, and improve the mechanical properties of materials.
1. Compared with other traditional pipes, seamless steel pipes have the advantages of light raw material, high strength, good resistance, high internal pressure, sensitive production and application, and it can be used to messy or harsh geological conditions.
2. However, there is a large rate of steel pipes in the process of application, mainly due to the trouble of internal and external anti-corrosion treatment. The first question of external anti-corrosion is very important, the quality of external anti-corrosion directly affects its service life. At present, the external anti-corrosion of domestic steel pipes is mainly: concealment method. All steel pipes are required to be reinforced or extra strengthened external corrosion protection, and cathodic protection is promoted in some areas. The hidden external anti-corrosion methods are usually coatings such as petroleum asphalt and epoxy coal tar pitch. The latter is not easy to solidify at low temperature, and there are more questions in the field welding joint construction. This chlorosulfonated polyethylene was used before, because most of the solvents are easy to produce pinholes, and the resistance to penetration is not up to standard. Some areas are clear about it and no longer used it. As for cathodic protection, its anti-corrosion effect is better, but because of the sacrificial anode method, the anode must be replaced regularly in future operation, which increases the operation cost and operation.
Besides, there are three methods for seamless steel pipes supply: anticorrosive coating, resin mortar and cement mortar. There are two questions in the three methods: the first is about the bond strength between anticorrosive coating and steel pipes, which has been mentioned before by cement mortar. As for anticorrosive coating and resin mortar, both the inner and outer surfaces of steel pipes are required to be completely derusted before construction, but it is difficult to achieve this point. Therefore, the rust spots will form the source of delamination in the future, forming corrosion and scaling. The second is that most of the steel pipes are butt welded on site, and anticorrosion is carried out after welding. It can only be done manually. The quality is not easy to control, and the pipe with smaller diameter is no longer anticorrosive because personnels can not enter the construction. It also forms the hidden danger of weld damage in the future.
According to the analysis of several pipe burst accidents, it is mainly caused by weld corrosion with low weld quality.
3. The cost of seamless steel pipe supply is high.
4. Poor hydraulic function and high energy consumption. The internal roughness coefficient of the steel pipe is between 0.013-0.014. Therefore, for the pipeline with the same water delivery capacity and equal pipe diameter, the resistance along the pipeline is high. The demand increases the pump head and the initial investment, and the operation cost increases greatly due to the large power consumption.
5. The pipeline has the disadvantage of poor bearing capacity to water hammer.
