Extrusion production process of precision seamless steel pipe

The production of precision seamless steel tubes typically follows a process involving furnace heating and electro-slag remelting (ESR), followed by forging or rolling of billets. The resulting products can be round bars, square flats, or forgings. These materials are further processed, often into special shapes, with a metal utilization rate of about 30%. Using the extrusion method for production offers several advantages:

- Optimized Stress State: During the hot extrusion process, precision seamless steel tubes achieve an optimal stress state, reducing internal defects.

- Versatile Cross-Sectional Shapes: Extrusion allows for easy implementation of diverse cross-sectional shapes, making it suitable for varied and small batch production.

- Uniform Performance: The process ensures uniformity of performance in all directions.

The main production process for extrusion includes:

Electric Arc Furnace (EAF) + ESR

Forging or rolling cogging

Induction heating

Extrusion

Annealing

Differences Between Extrusion and Forging/Rolling

- Heating Temperature: Precision seamless extrusion requires heating temperatures that are 30-60°C higher than those used in forging or rolling.

- Deformation Speed: The extrusion process involves high-speed deformation, requiring only 2-4 seconds for the deformed steel.

- Metal Consumption: Extrusion involves multiple steps, leading to higher metal consumption.

In summary, the extrusion process for producing precision seamless steel pipes enhances product quality by minimizing internal defects, accommodating various shapes, and ensuring uniform performance, despite the higher metal consumption and temperature requirements compared to forging and rolling.