Cold-drawn seamless tube is a kind of seamless pipe. Seamless pipe is a long steel material with a hollow cross-section and no seams around it. Compared with welded steel pipes, cold-drawn seamless pipes are a type of steel processed through a series of cold drawing, cold bending and other technologies in a normal temperature environment. Compared with cold-drawn pipes, hot-rolled seamless pipes are a type of steel that is processed above the recrystallization temperature.
Manufacturing process of cold drawn seamless tube
1. Raw material preparation
The raw material of cold drawn seamless steel pipe is steel ingot or billet, and its chemical composition should comply with relevant national standards. Steel needs to be surface treated so that its finish and surface roughness are controlled.
2. Preheating
Steel needs to be cold drawn multiple times during the cold drawing process. In order to avoid steel pipe deformation and quality problems caused by deformation and strain caused by the cold drawing process, the steel needs to be preheated. The preheating temperature is generally around 600°C and the time is about 30 minutes.
3. Cutting
The preheated steel is cut through machinery and equipment to obtain steel pipe blanks of appropriate size.
4. Pickling
Put the steel pipe blank into the acid solution, and use chemical reactions to remove rust, oxide scale and other impurities on its surface, making the steel surface cleaner and reducing the damage to the steel pipe caused by cold drawing processing.
5. Welding
For long steel products, in order to reduce waste, some shorter steel pipe blanks can be cut out in the middle of a section of steel using the principle of high-frequency induction heating, and then these shorter steel pipe blanks are welded to obtain long steel pipe blanks.
6. Cold drawing processing
The steel pipe blank is processed with a cold drawing machine, and the steel is slowly deformed through the drilling die until it becomes a seamless steel pipe. During the cold drawing process, attention should be paid to controlling parameters such as temperature, perforation, and drawing speed to ensure the stability of steel pipe quality.
7. Heat treatment
After the cold-drawn seamless steel pipe process is completed, heat treatment can improve its mechanical properties and increase its ductility and toughness. The heat treatment temperature is generally around 800°C and the time is about 1 hour.
8. Surface treatment
The surface of seamless steel pipes needs to undergo rust removal, grinding, painting and other treatments to achieve the effects of beauty, corrosion resistance and reduced surface roughness.
9. Inspection
The final step is testing and inspection. The inspection mainly includes appearance inspection and performance inspection. Observation inspection mainly checks the surface quality, dimensional accuracy, etc. of the steel pipe; performance inspection involves conducting tensile, impact, hardness and other tests on the steel pipe to check whether its mechanical properties meet the standard requirements. During the inspection process, inspection standards and inspection methods need to be strictly controlled to ensure that the quality of the final product meets customer requirements.
The above are the main steps in the production process of cold drawn seamless steel pipe. Each step requires strict control of the process flow and involves issues such as accuracy requirements of machinery and equipment. Only by strictly implementing production operating procedures and quality control standards can high-quality seamless steel pipes be produced.
Manufacturing process of cold drawn seamless tube
1. Raw material preparation
The raw material of cold drawn seamless steel pipe is steel ingot or billet, and its chemical composition should comply with relevant national standards. Steel needs to be surface treated so that its finish and surface roughness are controlled.
2. Preheating
Steel needs to be cold drawn multiple times during the cold drawing process. In order to avoid steel pipe deformation and quality problems caused by deformation and strain caused by the cold drawing process, the steel needs to be preheated. The preheating temperature is generally around 600°C and the time is about 30 minutes.
3. Cutting
The preheated steel is cut through machinery and equipment to obtain steel pipe blanks of appropriate size.
4. Pickling
Put the steel pipe blank into the acid solution, and use chemical reactions to remove rust, oxide scale and other impurities on its surface, making the steel surface cleaner and reducing the damage to the steel pipe caused by cold drawing processing.
5. Welding
For long steel products, in order to reduce waste, some shorter steel pipe blanks can be cut out in the middle of a section of steel using the principle of high-frequency induction heating, and then these shorter steel pipe blanks are welded to obtain long steel pipe blanks.
6. Cold drawing processing
The steel pipe blank is processed with a cold drawing machine, and the steel is slowly deformed through the drilling die until it becomes a seamless steel pipe. During the cold drawing process, attention should be paid to controlling parameters such as temperature, perforation, and drawing speed to ensure the stability of steel pipe quality.
7. Heat treatment
After the cold-drawn seamless steel pipe process is completed, heat treatment can improve its mechanical properties and increase its ductility and toughness. The heat treatment temperature is generally around 800°C and the time is about 1 hour.
8. Surface treatment
The surface of seamless steel pipes needs to undergo rust removal, grinding, painting and other treatments to achieve the effects of beauty, corrosion resistance and reduced surface roughness.
9. Inspection
The final step is testing and inspection. The inspection mainly includes appearance inspection and performance inspection. Observation inspection mainly checks the surface quality, dimensional accuracy, etc. of the steel pipe; performance inspection involves conducting tensile, impact, hardness and other tests on the steel pipe to check whether its mechanical properties meet the standard requirements. During the inspection process, inspection standards and inspection methods need to be strictly controlled to ensure that the quality of the final product meets customer requirements.
The above are the main steps in the production process of cold drawn seamless steel pipe. Each step requires strict control of the process flow and involves issues such as accuracy requirements of machinery and equipment. Only by strictly implementing production operating procedures and quality control standards can high-quality seamless steel pipes be produced.
