High-strength Carbon Steel Tubes For Low And Medium-pressure Boilers
Gb 3087 grade 20 seamless tubes, compliant with gb 3087-2008, are high-quality carbon structural steel tubes designed for low and medium-pressure boilers, offering high strength and good weldability for heating surfaces and steam pipelines.
High-strength Carbon Steel Tubes For Low And Medium-pressure Boilers
Gb 3087 grade 20 seamless tubes, compliant with gb 3087-2008, are high-quality carbon structural steel tubes designed for low and medium-pressure boilers, offering high strength and good weldability for heating surfaces and steam pipelines.
GB 3087 Grade 20 seamless tubes, compliant with GB 3087-2008, are high-quality carbon structural steel tubes designed for low and medium-pressure boilers operating at pressures ≤5.9 MPa. These tubes are manufactured using seamless processes, either hot-rolled (extruded, expanded) or cold-drawn (rolled), ensuring uniform quality and enhanced mechanical properties. They are suitable for heating surfaces with wall temperatures ≤510°C and headers or steam pipes with wall temperatures ≤450°C, as per the standard.
Available in outer diameters from 33 mm to 323 mm and wall thicknesses from 3.2 mm to 21 mm, GB 3087 Grade 20 seamless tubes offer superior tensile strength (410–550 MPa) and good plasticity compared to Grade 10. The manufacturing process involves electric furnace, oxygen converter, or open-hearth smelting, with tube blanks produced via hot rolling, continuous casting, or steel ingots. Normalizing heat treatment at 900–940°C enhances toughness and strength, while rigorous testing (hydraulic, flattening, flaring, and optional ultrasonic) ensures defect-free surfaces and compliance with GB/T 699 for chemical composition.
Compared to Grade 10 or alloy steel grades like 15CrMo, Grade 20 provides higher strength but slightly lower plasticity, making it suitable for applications requiring robust performance, such as boiler heating surfaces, steam pipelines, and heat exchangers. Weldability is good, typically using manual welding (e.g., E4303 or E4315 electrodes) or gas-shielded welding without preheating or post-weld heat treatment. These tubes are widely used in industrial boilers, locomotive boilers, and petrochemical systems, with surface finishes like varnishing or galvanizing to prevent rust. Delivery options include plain, beveled, or threaded ends.
GB 3087 Grade 20 seamless tubes are a reliable, high-performance solution for low and medium-pressure boiler systems, offering durability and cost-effectiveness in demanding industrial environments.
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.17–0.24 |
| Silicon (Si) | 0.17–0.37 |
| Manganese (Mn) | 0.38–0.65 |
| Phosphorus (P) | ≤0.035 |
| Sulfur (S) | ≤0.035 |
| Property | Value |
|---|---|
| Tensile Strength (MPa) | 410–550 |
| Yield Strength (MPa) | ≥245 |
| Elongation, min (%) | ≥21 |
| Impact Energy (J, 0°C) | ≥27 |
Tensile strength of 410–550 MPa for robust performance.
Weldable without preheating or post-weld treatment.
Handles up to 510°C for heating surfaces.
Uniform structure for pressure resistance.
Varnished or galvanized for rust protection.
Affordable for low/medium-pressure applications.
| Feature | GB 3087 Grade 20 | GB 3087 Grade 10 | 15CrMo (GB 5310) |
|---|---|---|---|
| Material Type | Carbon Steel | Carbon Steel | Low-Alloy Steel |
| Temperature Range | ≤510°C (heating surface) | ≤480°C (heating surface) | 450–650°C |
| Tensile Strength (MPa) | 410–550 | 335–475 | 440–640 |
| Yield Strength (MPa) | ≥245 | ≥195 | ≥235 |
| Weldability | Good | Excellent | Moderate |
| Applications | Low/medium-pressure boilers | Low/medium-pressure boilers | High-pressure boilers |
| Key Advantage | Higher strength | High plasticity | High thermal strength |
GB 3087 Grade 20 seamless tubes are essential for low and medium-pressure boiler systems, heat exchangers, and locomotive boilers, offering high strength and reliability.
Used in heating surfaces up to 510°C.
Efficient thermal transfer in low-pressure systems.
Reliable for steam pipelines up to 450°C.
Handles medium-pressure steam flow.
Resists thermal stress in boiler systems.
Used in low-pressure fluid pipelines.
Gb 3087 grade 10 seamless pipes, compliant with gb...
