Q345 STEEL – STRUCTURAL STEEL
Description
What is Q345 steel?
Q345 is a low-alloy, high-strength structural steel composed of approximately 98-99% iron and 1-2% alloying elements such as carbon, manganese, silicon, and trace amounts of other elements like phosphorus and sulfur. It is typically available in solid, flat, or plate forms and has a greyish-metallic appearance. It is primarily used in construction and engineering applications, such as bridges, buildings, and machinery. The steel is processed through hot rolling, which enhances its mechanical properties. Q345 can be further classified into subgrades like Q345A, Q345B, Q345C, Q345D, and Q345E, based on the impact toughness and testing temperature.Characteristics of Q345 Steel
Q345 steel offers an enhanced strength-to-weight ratio, making it ideal for large-scale projects. It has superior toughness, high fatigue resistance, improved corrosion resistance, and excellent low-temperature performance. Additionally, Q345 steel is eco-friendly and recyclable, contributing to sustainable construction practices. Standardized production ensures consistent quality, while its machinability and weldability facilitate easy fabrication and assembly of complex structures. However, it may not be suitable for applications requiring extremely high corrosion resistance or performance in very high-temperature environments.Chemical Compositions
| lement | Carbon (C) | Silicon (Si) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Chromium (Cr) | Nickel (Ni) | Iron (Fe) |
|---|---|---|---|---|---|---|---|---|
| 310 | ≤ 0.25% | ≤ 1.50% | ≤ 2.00% | ≤ 0.045% | ≤ 0.030% | 24.0-26.0% | 19.0-22.0% | Balance |
| 310S | ≤ 0.08% | ≤ 1.50% | ≤ 2.00% | ≤ 0.045% | ≤ 0.030% | 24.0-26.0% | 19.0-22.0% | Balance |
Physical Properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| Melting Point | 1420-1450°C | 2588-2642°F |
| Thermal Conductivity | 24.3 W/m·K | 14.1 BTU·in/hr·ft²·°F |
| Electrical Resistivity | 0.15 µΩ·m | 0.15 µΩ·m |
| Specific Heat Capacity | 486 J/kg·K | 0.116 BTU/lb·°F |
| Thermal Expansion Coefficient | 11.7 x 10⁻⁶ /°C | 6.5 x 10⁻⁶ /°F |
Mechanical Properties
| Property | Value (Metric) | Value (Imperial) |
|---|---|---|
| Tensile Strength | 470-630 MPa | 68-91 ksi |
| Yield Strength | 345 MPa | 50 ksi |
| Vickers Hardness (HV) | 140-180 | 140-180 |
| Brinell Hardness (HB) | 135-160 | 135-160 |
| Rockwell Hardness (HRC) | 20-25 | 20-25 |
| Elongation | 20-26% | 20-26% |
| Elastic Modulus | 210 GPa | 30.5 Msi |
Industries & Applications
| Applications | Components |
|---|---|
| Construction | Beams, Columns, Trusses, Frames |
| Industrial Facilities | Factory structures, Warehouse supports, Heavy machinery frameworks, Plant columns |
| Bridges | Beam bridges, Arch bridges, Suspension bridges, Truss bridges |
| Commercial Buildings | Office building frameworks, Retail store supports, Parking garage columns, Shopping mall trusses |
| Residential Buildings | Apartment building beams, Condominium columns, Housing complex trusses, Residential steel frames |
| Infrastructure | Roadway bridges, Rail bridge supports, Overpass trusses, Utility tower frames |
| Agriculture | Barn frameworks, Silo supports, Greenhouse structures, Farm machinery components |
| Energy | Wind turbine towers, Power plant frameworks, Oil rig structures, Solar panel mounts |
Machining
Q345 Heat Treating Instructions: Q345 steel is typically used in its as-rolled or normalized condition and does not require additional heat treatment. If needed, normalizing can be applied to enhance its mechanical properties by refining the grain structure.
Q345 Surface Finish: The surface of Q345 steel can be treated through methods such as painting, galvanizing, or powder coating to improve corrosion resistance and durability, particularly in outdoor or harsh environments.
Custom grades can be produced upon request to meet specific requirements.
Our Service
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