ASTM A618 HSLA Steel Grade Ib

ASTM A618 HSLA Steel Grade Ib, Thickness < 19 mm (3/4 in.) Product Information -:- For detailed product information, please contact sales. -: ASTM A618 HSLA Steel Grade Ib, Thickness < 19 mm (3/4 in.) Synonyms -:- For detailed product information, please contact sales. -:

ASTM A618 HSLA Steel Grade Ib, Thickness < 19 mm (3/4 in.) Product Information -:- For detailed product information, please contact sales. -: ### **ASTM A618 Grade Ib: Hot-Formed Welded High Strength Low-Alloy Structural Steel Tubing (Thickness < 19 mm / ¾ in.)** #### **1. Overview** ASTM A618 Grade Ib is a specification for **hot-formed welded high strength low-alloy (HSLA) structural steel tubing** with **superior atmospheric corrosion resistance**, designed for thicknesses less than 19 mm (¾ inch). This weathering steel develops a dense, adherent protective oxide patina when exposed to atmospheric conditions, providing approximately **four times better corrosion resistance** than conventional carbon steel. Grade Ib offers an excellent balance of strength, durability, and aesthetic appeal for structural tubular applications in exposed environments. #### **2. Chemical Composition** The chemical composition is precisely controlled for enhanced corrosion resistance: | Element | Composition (%) | |---------|-----------------| | Carbon (C) | 0.22 max | | Manganese (Mn) | 0.75 - 1.25 | | Phosphorus (P) | 0.04 max | | Sulfur (S) | 0.05 max | | Silicon (Si) | 0.15 - 0.50 | | Copper (Cu) | 0.20 - 0.40 | | Chromium (Cr) | 0.40 - 0.70 | | Nickel (Ni) | 0.25 - 0.50 | **Enhanced Composition Features:** - **Optimized Copper-Chromium-Nickel System**: Creates superior protective patina formation - **Controlled Carbon Content**: Maintains excellent weldability for tubular structures - **Enhanced Nickel Content**: Improves overall corrosion resistance and toughness - **Balanced Silicon Level**: Ensures good strength while maintaining formability #### **3. Physical & Mechanical Properties** **Mechanical Properties (for thickness < 19 mm / ¾ in.):** | Property | Requirement | |----------|-------------| | **Tensile Strength** | 70 ksi min (485 MPa min) | | **Yield Strength** | 50 ksi min (345 MPa min) | | **Elongation in 2 inches** | 22% min | | **Bend Test** | Bend 180° around diameter equal to thickness | **Superior Performance Characteristics:** - **Enhanced Atmospheric Corrosion Resistance**: 4x better than carbon steel without copper - **High Strength-to-Weight Ratio**: Enables lightweight structural designs - **Excellent Weldability**: All standard welding processes applicable - **Good Cold Forming Capability**: Suitable for moderate fabrication requirements **Physical Properties (Typical):** - **Density**: 0.284 lb/in³ (7,850 kg/m³) - **Modulus of Elasticity**: 29,000 ksi (200 GPa) - **Poisson's Ratio**: 0.29 - **Coefficient of Thermal Expansion**: 6.5 × 10⁻⁶/°F (11.7 × 10⁻⁶/°C) - **Thermal Conductivity**: 42.5 W/m·K at 212°F (100°C) #### **4. Product Applications** Grade Ib finds extensive use in demanding structural tubular applications: **Architectural and Building Structures:** - Architectural exposed structural columns - Building facade support systems - Monumental structural elements - High-end architectural features **Bridge and Infrastructure:** - Bridge structural members and trusses - Highway sign support structures - Pedestrian bridge components - Transportation infrastructure elements **Industrial and Special Applications:** - Industrial platform structural frames - Material handling system supports - Special equipment structural components - Heavy-duty structural frameworks #### **5. International Standards & Equivalents** | Region/Country | Standard | Equivalent Grade | Notes | |----------------|----------|------------------|-------| | **International** | **ISO 4952** | E460D | Weathering steel equivalent | | **Europe** | **EN 10219** | S355J2H | Hollow structural sections | | **Japan** | **JIS G3475** | STKN 400B | High-strength carbon steel tubes | | **China** | **GB/T 6728** | Q355GNH | Weathering steel hollow sections | **A618 Grade Ib Special Characteristics:** | Parameter | Grade Ia | Grade Ib | |-----------|----------|----------| | **Corrosion Resistance** | 2x Carbon Steel | 4x Carbon Steel | | **Nickel Content** | 0.25% max | 0.25-0.50% | | **Typical Applications** | General Structural | Enhanced Performance | #### **6. Fabrication & Quality Assurance** **Welding and Fabrication Requirements:** - **Pre-heat Requirements**: 250-400°F (120-205°C) based on section thickness - **Welding Processes**: GMAW, FCAW, GTAW with low-hydrogen consumables - **Interpass Control**: Maximum 400°F (205°C) - **Post-Weld Treatment**: Generally not required for thin sections **Tubing Manufacturing Quality:** - **Hot-Forming Process**: Ensures uniform mechanical properties - **Weld Integrity**: Full penetration welds with consistent quality - **Dimensional Accuracy**: Tight tolerances for structural applications - **Surface Quality**: Suitable for weathering characteristics development **Corrosion Performance Features:** - **Rapid Patina Formation**: Develops within 1-3 years in proper conditions - **Self-Protecting Mechanism**: Eliminates need for protective coatings - **Environmental Versatility**: Performs well in various atmospheric conditions - **Low Maintenance**: Minimal upkeep after patina establishment **Quality Control Protocols:** - **Comprehensive Testing**: Tension, bend, and flattening tests - **Chemical Verification**: Strict control of alloying elements - **Dimensional Inspection**: Precise measurement of tubular sections - **Surface Quality Assessment**: Visual and non-destructive examination --- **Technical Advantages:** - **Superior corrosion protection** in exposed environments - **Excellent strength-to-weight ratio** for efficient designs - **Aesthetically pleasing weathered appearance** - **Reduced lifecycle costs** through eliminated maintenance **Design Considerations:** - **Optimize section designs** for weathering performance - **Ensure proper drainage** in tubular configurations - **Select compatible connection** methods and materials - **Consider environmental factors** in design calculations **Service Limitations:** - **Not suitable** for continuous immersion conditions - **Avoid crevice corrosion** traps in designs - **Limited performance** in severe marine environments - **Maximum service temperature** of 750°F (400°C) **Disclaimer:** This technical information serves as a reference guide. For structural applications employing A618 Grade Ib steel tubing, consultation with the latest ASTM A618 specification and relevant structural design codes is essential. All fabrication must adhere to established procedures for weathering steel tubular structures, and designs require approval by qualified professional engineers experienced with hollow structural sections and weathering steel performance characteristics. -:- For detailed product information, please contact sales. -: ASTM A618 HSLA Steel Grade Ib, Thickness < 19 mm (3/4 in.) Specification Dimensions Size： Diameter 20-1000 mm Length <4489 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: ASTM A618 HSLA Steel Grade Ib, Thickness < 19 mm (3/4 in.) Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A618 HSLA Steel Grade Ib, Thickness < 19 mm (3/4 in.) -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A618 HSLA Steel Grade Ib, Thickness < 19 mm (3/4 in.) -:- For detailed product information, please contact sales. -:

Packing of ASTM A618 HSLA Steel Grade Ib, Thickness < 19 mm (3/4 in.) -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 960 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition