Hot-Rolled Seamless Carbon Steel Pipes
Hot-Rolled Seamless Carbon Steel Pipes - Full-Scale, High-Pressure Capable, Fully Traceable Industrial Conduits
Process Principle: One-Piece Forging from Billet to Pipe
Process Principle: One-Piece Forging from Billet to Pipe
Hot-rolled seamless pipes are made by heating solid round billets1200°C - 1250°C(above recrystallization temperature) in a rotary hearth furnace, followed by descaling, piercing into a hollow shell in a cross-roll piercer, and then reducing diameter & wall thickness through continuous rolling mills (e.g., ASSEL mill, Accu-Roll mill) or plug mills. Finally, a sizing mill ensures precise outer diameter. The entire process keeps the metal in the austenite phase, delivering fine grain structure without any weld seam.
Metallurgical advantages over cold-drawn or welded pipes:
Uniform grain size through dynamic recrystallization
High isotropy - minimal difference between longitudinal and transverse properties
No residual welding stress or heat-affected zone
Capable of thick wall (≥60mm) and large OD (≥630mm)
Competitive Advantages
Full Size Coverage - Reduce Welding
Large OD hot-rolled pipes directly serve hydraulic cylinders, columns, and bridge casings, eliminating weld seams from joining smaller pipes.
Surface Quality Control
● Outer surface: as-rolled (mill scale) or blasted (Sa2.5)
● Inner surface: smooth, free from laps and inner folds, Ra ≤ 6.3μm
● Optional: internal rust preventive oil or external black paint
Customized Processing
● End beveling (30° / 37.5°)
● Cut-to-length (±1.5mm accuracy)
● Threading (NPT / BSP / tubing threads)
● Heat treatment: annealing, normalizing, stress relieving
Full Traceability System
Each pipe is marked (sprayed/labeled) with: heat number, batch number, size, grade, standard. Deliverables include:
● Raw material certificate
● Heat treatment record
● Mechanical test report
● NDT report
● Third-party inspection (SGS/BV/Intertek) available
Typical Applications
Industry | Application |
|---|---|
Petrochemical | High-pressure process piping |
Construction Machinery | Hydraulic cylinder tubes, piston rod sleeves |
Shipbuilding | Boiler & superheater tubes |
Power Generation | High-pressure feedwater & steam lines |
Mining & Construction | Columns, piling pipes, slurry lines |
General Machining | Shaft sleeves, rollers, flange blanks |
Quality Assurance & Supply Commitment
Testing equipment: Eddy current tester, hydrostatic tester, universal testing machine, impact tester, PMI (spectrometer), metallurgical microscope
Certifications: ISO 9001:2015, API 5L Monogram (if applicable), PED 2014/68/EU
Delivery condition: Hot-rolled, normalized, N T, stress-relieved
Packing: Hexagonal bundles steel strips waterproof cover, plastic end caps, sea-worthy
We don't just sell steel pipes. We deliver calculable, safe pressure conduits for your critical infrastructure.
