Production process:
（1） Strict requirements for chemical composition, requiring a higher carbon and silicon content in the original molten iron compared to gray cast iron, reducing the content of manganese, phosphorus, and sulfur in ductile iron
（2） The discharge temperature of molten iron is higher than that of gray cast iron to compensate for the loss of molten iron temperature during spheroidization and inoculation treatment
（3） Perform spheroidization treatment by adding spheroidizing agents to the molten iron
（4） Add inoculant for inoculation treatment
（5） Ductile iron has poor flowability and large shrinkage, so it requires a higher pouring temperature and a larger pouring system size. Reasonable use of risers and chilled iron should follow the principle of sequential solidification
（6） Perform heat treatment

Carbon steel pipe producing process:
1. Round pipe billets are cut into billets of approximately 1 meter in length by a cutting machine and sent via a conveyor belt to be heated in a furnace.The billet is heated in the furnace at a temperature of about 1200 degrees Celsius. The fuel is hydrogen or acetylene.
2. After the round billets come out of the furnace they are pierced by a pressure piercing machine. The more common piercing machine is the conical roll piercing machine. After that, the round billet is successively rolled by three-roll tilting, continuous rolling or extrusion.
3. After extrusion, the pipe is taken off for sizing. Sizing machine through the conical drill bit rotating at high speed into the steel embryo perforation, the formation of steel pipe. The inner diameter of the steel pipe is determined by the length of the outer diameter of the drill bit of the sizing machine.
4. After sizing, the steel pipe enters a cooling tower and is cooled by spraying water. After cooling, it is straightened.
5. A conveyor belt sends the steel pipe to a metal flaw detector (or water pressure test) for internal flaw detection.

Carbon steel pipe producing process:
1. Round pipe billets are cut into billets of approximately 1 meter in length by a cutting machine and sent via a conveyor belt to be heated in a furnace.The billet is heated in the furnace at a temperature of about 1200 degrees Celsius. The fuel is hydrogen or acetylene.
2. After the round billets come out of the furnace they are pierced by a pressure piercing machine. The more common piercing machine is the conical roll piercing machine. After that, the round billet is successively rolled by three-roll tilting, continuous rolling or extrusion.
3. After extrusion, the pipe is taken off for sizing. Sizing machine through the conical drill bit rotating at high speed into the steel embryo perforation, the formation of steel pipe. The inner diameter of the steel pipe is determined by the length of the outer diameter of the drill bit of the sizing machine.
4. After sizing, the steel pipe enters a cooling tower and is cooled by spraying water. After cooling, it is straightened.
5. A conveyor belt sends the steel pipe to a metal flaw detector (or water pressure test) for internal flaw detection.

Carbon steel pipe producing process:
1. Round pipe billets are cut into billets of approximately 1 meter in length by a cutting machine and sent via a conveyor belt to be heated in a furnace.The billet is heated in the furnace at a temperature of about 1200 degrees Celsius. The fuel is hydrogen or acetylene.
2. After the round billets come out of the furnace they are pierced by a pressure piercing machine. The more common piercing machine is the conical roll piercing machine. After that, the round billet is successively rolled by three-roll tilting, continuous rolling or extrusion.
3. After extrusion, the pipe is taken off for sizing. Sizing machine through the conical drill bit rotating at high speed into the steel embryo perforation, the formation of steel pipe. The inner diameter of the steel pipe is determined by the length of the outer diameter of the drill bit of the sizing machine.
4. After sizing, the steel pipe enters a cooling tower and is cooled by spraying water. After cooling, it is straightened.
5. A conveyor belt sends the steel pipe to a metal flaw detector (or water pressure test) for internal flaw detection.

Production process:
（1） Strict requirements for chemical composition, requiring a higher carbon and silicon content in the original molten iron compared to gray cast iron, reducing the content of manganese, phosphorus, and sulfur in ductile iron
（2） The discharge temperature of molten iron is higher than that of gray cast iron to compensate for the loss of molten iron temperature during spheroidization and inoculation treatment
（3） Perform spheroidization treatment by adding spheroidizing agents to the molten iron
（4） Add inoculant for inoculation treatment
（5） Ductile iron has poor flowability and large shrinkage, so it requires a higher pouring temperature and a larger pouring system size. Reasonable use of risers and chilled iron should follow the principle of sequential solidification
（6） Perform heat treatment

Standard:
API SPEC 5L - American Petroleum Institute
GB/T9711- Chinese National Standard
Purpose:
Oxygen, water, and oil delivery pipes used in the petroleum and natural gas industries
Main steel pipe grades for production:
B. X42, X52, X60, X65, X70 L245 L290 L320 L360 L390 L450 L485