SB410: Carbon Steel for Low-Pressure Boilers and Pressure Vessels
SB410 carbon steel, specified under JIS G3103 standard, is a low-alloy carbon steel primarily designed for fabricating low-pressure boilers, pressure vessels, and related components. With its controlled composition and robust mechanical properties, it offers reliable performance in moderate-temperature and pressure environments, ensuring safety and durability in industrial applications. This article explores its chemical makeup, mechanical characteristics, production methods, usage areas, and comparative insights.
1. Core Chemical Composition (JIS G3103 Standard)
| Element | Content Range | Function |
|---|---|---|
| Carbon (C) | ≤ 0.30% | Provides basic strength; limited to ensure weldability and ductility |
| Manganese (Mn) | 0.30 – 0.90% | Enhances deoxidation and toughness; improves hot working properties |
| Phosphorus (P) | ≤ 0.035% | Controlled impurity; minimizes brittleness and embrittlement risks |
| Sulfur (S) | ≤ 0.035% | Restricted to prevent hot shortness and ensure good forgeability |
| Silicon (Si) | ≤ 0.55% | Aids in deoxidation during smelting; supports oxidation resistance |
2. Key Mechanical Properties (Room Temperature)
- Tensile Strength: 410 – 530 MPa (adequate for pressure containment)
- Yield Strength: ≥ 235 MPa (ensures deformation resistance under load)
- Elongation: ≥ 22% (sufficient ductility for forming and fabrication)
- Hardness (HB): ≤ 170 (Brinell; facilitates machining and assembly)
- Impact Toughness: Suitable for low-temperature service up to -20°C without fracturing
3. Manufacturing Process Characteristics
- Smelting: Basic oxygen furnace (BOF) or electric arc furnace (EAF) with ladle refining to achieve low impurity levels and uniform composition.
- Hot Rolling: Processed at 850-1100°C to produce plates or sheets, followed by controlled cooling to refine grain structure and enhance toughness.
- Normalization: Heat treatment at 880-950°C with air cooling to relieve internal stresses and improve uniformity in mechanical properties.
- Testing & Inspection: Ultrasonic testing for internal defects, tensile and bend tests per JIS standards to verify compliance.
- Surface Preparation: Shot blasting or pickling to remove scale, ensuring clean surfaces for welding and coating applications.
4. Typical Application Fields
Boiler Manufacturing
Low-pressure steam boilers, fire tubes, and economizers — ideal for generating steam in industrial heating systems.
Pressure Vessels
Storage tanks for gases and liquids under moderate pressure, such as compressed air receivers and hot water tanks.
Industrial Piping
Headers, manifolds, and piping components in power plants and chemical processing for low-corrosion duties.
General Fabrication
Structural components in machinery housings and supports where cost-effective strength is required.
5. Difference from Similar Grades (SB410 vs SB450 vs SB480)
| Grade | Tensile Strength (MPa) | Key Advantage | Suitable Scenario |
|---|---|---|---|
| SB410 | 410 – 530 | Cost-effective with good weldability | Low-pressure boilers (up to 1.75 MPa) |
| SB450 | 450 – 580 | Higher strength for increased loads | Medium-pressure vessels and pipes |
| SB480 | 480 – 620 | Superior tensile properties | High-stress boiler components |
6. Selection & Usage Precautions
- Pressure Limits: Designed for service pressures not exceeding 1.75 MPa; for higher pressures, opt for alloy steels like SA516.
- Welding Guidelines: Preheat at 100-150°C for thicknesses over 20mm; use low-hydrogen electrodes (e.g., E7018) to prevent cracking.
- Corrosion Protection: Apply protective coatings in humid or corrosive atmospheres to extend service life.
- Quality Assurance: Ensure material traceability with mill test certificates (MTC) confirming JIS G3103 compliance and hydrostatic test results.
7. Get a Carbon Steel Quote
If you need customized SB410 carbon steel products (plates, sheets, pipes) or want to get a detailed price quote, please contact our team directly. Our specialists will provide professional technical support and competitive pricing based on your requirements.