Cold-rolled steel pipe
Cold-rolled steel pipe is a high-precision steel product widely used in industries requiring superior surface finish and dimensional accuracy. Manufactured through an advanced cold-rolling process, these pipes exhibit excellent mechanical properties and corrosion resistance.
Key Specifications of Cold-rolled Steel Pipe
- Material: Carbon steel, alloy steel, stainless steel
- Outer Diameter: 6mm to 426mm
- Wall Thickness: 0.5mm to 20mm
- Length: 3m to 12m (custom lengths available)
- Tolerance: ±0.05mm to ±0.15mm
Mechanical Properties Comparison
| Property | Cold-rolled Steel Pipe | Hot-rolled Steel Pipe |
|---|---|---|
| Tensile Strength | 450-850 MPa | 350-600 MPa |
| Yield Strength | 300-700 MPa | 200-450 MPa |
| Elongation | 15-30% | 20-40% |
| Surface Roughness | 0.8-3.2 μm | 6.3-12.5 μm |
Applications of Cold-rolled Steel Pipe
- Automotive components (shafts, chassis parts)
- Hydraulic and pneumatic cylinders
- Precision machinery and equipment
- Architectural applications
- Oil and gas transmission
Cold-rolled Steel Pipe FAQ
Q: What are the main advantages of cold-rolled steel pipe over hot-rolled pipe?
A: Cold-rolled steel pipe offers several advantages including tighter dimensional tolerances (typically ±0.1mm compared to ±0.5mm for hot-rolled), superior surface finish (smoothness 4-8 times better), and enhanced mechanical properties due to work hardening during the cold-rolling process. The cold-working process also improves yield strength by 10-30% compared to equivalent hot-rolled products.
Q: How should cold-rolled steel pipes be stored to prevent corrosion?
A: Cold-rolled steel pipes should be stored in a dry, well-ventilated warehouse away from corrosive elements. For long-term storage, we recommend applying anti-corrosion oil or using VCI (Volatile Corrosion Inhibitor) packaging. Pipes should be kept on wooden pallets or racks to prevent ground moisture contact, and stacked with proper spacing between layers to allow air circulation.
Q: What quality certifications should I look for when purchasing cold-rolled steel pipe?
A: Reputable manufacturers should provide certifications including ISO 9001 for quality management, EN 10219 for cold-formed welded structural hollow sections, ASTM A500 for structural tubing, and material test reports (MTRs) showing chemical composition and mechanical properties. For specific applications, look for additional certifications like API 5CT for oil country tubular goods or PED certification for pressure equipment.
Quality Inspection Standards
| Inspection Item | Method | Standard |
|---|---|---|
| Outer Diameter | Micrometer | ±0.1% of nominal diameter |
| Wall Thickness | Ultrasonic testing | ±5% of nominal thickness |
| Straightness | Straight edge measurement | ≤1.5mm per meter |
| Surface Defects | Visual inspection | No cracks, folds or inclusions |
Cold-rolled Steel Pipe Processing Capabilities
- Precision cutting to ±0.2mm tolerance
- Threading (metric, NPT, BSPP, BSPT)
- Heat treatment (annealing, normalizing)
- Surface treatments (zinc plating, painting, powder coating)
- CNC machining (drilling, milling, turning)