There are four main production processes for thick-walled seamless steel pipes: hot rolling, cold drawing, cold rolling, and spinning. The production process of thick-walled seamless steel pipes seems professional, but it is not difficult to understand! Many friends often encounter these troubles when purchasing or using: insufficient strength of steel pipes, rough inner walls, long delivery cycles, and even cost surges due to improper process selection. Don’t worry, today we will start from the actual pain points and disassemble the four core production processes in the most down-to-earth way to help you avoid pitfalls easily!
1. Production process of thick-walled seamless steel pipes—hot rolling method (hot extrusion)
Pain points: Traditional processes are inefficient and dimensional accuracy is difficult to control
This is the most classic method, just like “kneading dough”-the heated red steel billet is hollowed out with a piercer, and then repeatedly rolled and formed by a tube rolling machine. The advantage is that it can produce ultra-large diameter steel pipes (up to 650mm!), but the surface is prone to oxide scale and requires additional polishing. Suitable for “rough work” scenes such as thermal power generation and petroleum steel pipes.
2. Production process of thick-walled seamless steel pipes—cold drawing method
Pain point: thin-walled steel pipes are easy to deform and the processing cost is high
Treat the hot-rolled steel pipe as “plasticine” and use a mold to hard draw it at room temperature. Just like making hand-pulled noodles, the diameter shrinks a little with each pull. The surface of the steel pipe is as smooth as a mirror, and the size is accurate to the hair level (±0.05mm). Medical equipment and precision instruments love to be used. But be careful that too thin-walled steel pipes may be torn!
3. Production process of thick-walled seamless steel pipes—cold rolling method
Pain point: large equipment investment, small batch production is not cost-effective
It is equivalent to doing “SPA” for steel pipes: using a tapered mandrel to roll while rotating, the whole process is like twisting a towel. The biggest highlight is that it can produce ultra-thick-walled steel pipes (wall thickness of more than 100mm!), and the metal fiber is denser. High-pressure reactors in chemical equipment and sealed shells in nuclear power plants all rely on it. However, the production line costs hundreds of millions, which is suitable for enterprises with strong economic strength.
4. Production process of thick-walled seamless steel pipes—spinning method
Pain point: It is difficult to process special-shaped steel pipes
This is a new “black technology” that allows steel pipes to rotate and shape like pottery. It is especially suitable for manufacturing “high-end products” such as rocket engine casings and special-shaped military pipe fittings. The advantage is that it can achieve operation methods such as variable diameter and variable wall thickness, but the craftsmanship of the master directly determines the quality of the finished product. At present, there are no more than 10 manufacturers in China who have mastered the core technology.
Post time: Jun-20-2025