How is a seamless pipe made​

Seamless steel pipes are known for their durability and quality, which are
important for building, plumbing, and various industrial uses.

What is Seamless Steel Pipe?
Pipes without welds are called seamless pipes, often made of carbon steel,
stainless steel, or metal steel. Seamless pipes offer advantages such as
increased strength, reliability, and rust resistance, making them ideal for
critical industries like oil and gas, chemicals, and power generation.
How is a seamless pipe made?
1. Raw Material Selection
Choosing high-quality steel billets for uniform composition and structural
integrity.

2. Heating
Uniformly heating billets to around 1,200°C to facilitate deformation.

3. Rotary Piercing
Piercing heated billets using skewed rollers and a mandrel to create a hollow
shell.

4. Elongation and Sizing
Stretching and reducing the hollow shell to achieve the desired dimensions
using rolling mills.

5. Heat Treatment
Applying processes like normalizing and tempering to enhance mechanical
properties.

6. Straightening and Inspection
Correcting deformations and inspecting for defects using non-destructive
testing methods.

7. Cutting and Finishing
Cutting to specified lengths and applying surface finishes like threading or
coating

Comparison of the Processes
There are two main ways to make seamless pipes: hot-rolling and cold-drawing,
each with unique features for different uses.

Hot-rolled seamless pipes
Hot-rolled pipes are formed by passing heated steel billets through processes
like piercing and rolling. They are widely used in general structures and
mechanical structures, offering high production efficiency and relatively low
cost.

Cold-drawn seamless pipes
Cold-drawn pipes are produced by cold-drawing on hot-rolled seamless pipes,
resulting in higher dimensional accuracy and surface finish. They are ideal for
high-precision machinery manufacturing and hydraulic equipment where precision
is crucial.

hot and cold rolled seamless pipe
Hot-Rolled Seamless Pipe Cold-Rolled Seamless Pipe
Manufacturing Temperature Produced at high temperatures (>1,000°C)
Produced at room temperature or slightly elevated
Surface Finish Rough, may have scale Smooth, clean surface, minimal
oxidation
Strength Lower tensile strength and hardness Higher tensile
strength, more precise dimensions
Cost Less expensive More expensive due to additional processing
Applications Heavy-duty, low-precision uses Precision engineering,
automotive, aerospace, pressure vessels
Choosing the right type depends on specific engineering needs, performance
requirements, and manufacturing costs.

Rayoung has been a China SMLS Steel Pipe supplier and exporter since 1983. We
offer various oil, gas, and fire protection pipeline solutions. Our steel pipe
experts and efficient teams are available online!


Email: info@js07chinajsgj.com

Minimum Order: 10 pieces

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