Cold drawn Q420B seamless steel pipes combine the high strength and toughness of low-alloy structural steel with the precision and surface finish advantages of cold drawing.
These pipes are ideal for load-bearing applications, structural supports, and projects requiring tight dimensional tolerances. ASTM A252 Grade 3 ensures a high minimum yield strength, excellent weldability, and reliable impact resistance, making these pipes suitable for critical construction and industrial applications.
Material Characteristics
High Strength: Yield strength ≥ 420 MPa (for Ø ≤16mm)
Toughness & Ductility: Excellent elongation and impact energy at ambient and sub-zero temperatures
Weldability: Low carbon content (≤0.20%) with controlled S and P ensures good weldability
Cold Drawing Benefits:
Tighter dimensional tolerances
Smooth surface finish
Improved straightness and concentricity
Higher mechanical strength compared to hot-rolled pipes
Chemical Composition (Max %)
| Element | C | Mn | Si | P | S | V | Nb | Ti | Cr | Ni |
|---|---|---|---|---|---|---|---|---|---|---|
| Max % | 0.20 | 1.00–1.70 | 0.55 | 0.040 | 0.040 | 0.02–0.20 | 0.015–0.060 | 0.02–0.20 | 0.40 | 0.70 |
Mechanical Properties (GB/T 1591 Q420B / ASTM A252 Gr 3)
| Thickness / Diameter | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) | Impact Energy (J) |
|---|---|---|---|---|
| ≤16 mm | 420 | 520–680 | 18 | 34 @ +20℃ |
| >16–35 mm | 400 | 520–680 | 18 | 34 @ +20℃ |
| >35–50 mm | 380 | 520–680 | 18 | 34 @ +20℃ |
| >50–100 mm | 360 | 520–680 | 18 | 34 @ +20℃ |
Key Features
Precision Cold Drawing: Ensures accurate diameter and wall thickness
High-Strength Low-Alloy Steel: Ideal for structural supports and high-stress applications
Excellent Weldability & Toughness: Suitable for construction, bridge, and machinery applications
Durable & Reliable: Maintains strength and performance in harsh working conditions
Applications
Construction & Structural Engineering: Piling, steel structures, bridges, high-rise buildings
Industrial Machinery: Crane booms, support structures, and heavy-duty equipment
Energy & Infrastructure: Oil, gas, and water pipelines, offshore and onshore platforms
Marine & Transportation: Shipbuilding, railway components, and other high-strength requirements
