ASTM A709/A709M A709 Grade 345 Type 4 Introduce
ASTM A709/A709M A709 Grade 345 Type 4 is a type of high strength, low-alloy structural steel designed to provide superior corrosion resistance and enhanced strength at elevated temperatures. The standard specifies the grades, types, shapes and sizes of {stnadard} steel that meet the requirements for performance in various applications. A709/A709M steel is available as a full range of plates, sheets, strips, bars, shapes, and rounds and is used in a wide variety of applications in the construction industry.
Smelting temperature:1211°C - 1979°C
Application:Structural steel for bridge
ASTM A709/A709M A709 Grade 345 Type 4 Material Chemical Composition
The chemical composition of the ASTM A709/A709M A709 Grade 345 Type 4 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Nitrogen (N) | - | 0.0150 |
| Copper (Cu) | 0.2000 | - |
| Vanadium (V) | 0.0100 | 0.0150 |
| PhOsphorus (P) | - | 0.0400 |
| Sulfur (S) | - | 0.0500 |
| Manganese (Mn) | - | 1.3500 |
| Silicon (Si) | - | 0.4000 |
| Carbon (C) | - | 0.2300 |
| Silicon (Si) | 0.1500 | 0.4000 |
| Manganese (Mn) | - | 1.3500 |
| Copper (Cu) | - | 0.1800 |
| Carbon (C) | - | 0.2300 |
ASTM A709/A709M A709 Grade 345 Type 4 Material Mechanical Properties
ASTM A709/A709M A709 Grade 345 Type 4 steel is a highly engineered, low-alloy structural steel commonly used in modern engineering applications due to its exceptional combination of mechanical properties that make it an ideal choice for creating structures that need to be strong, durable, and yet lightweight. The steel is part of a family of steels known as ASTM A709/A709M A709 Grade 345 Type 4, and is produced in a variety of grades with different chemical compositions, mechanical properties, and physical characteristics.
The mechanical properties of the ASTM A709/A709M A709 Grade 345 Type 4 steel are as follows:
| YieldRp0.2 | ≤ 573 (MPa) |
| TeileRm | ≤ 219 (MPa) |
| ImpactKV/Ku | 32(J) |
| ElongationA | 13% |
| Reduction in cross section on fractureZ | 44% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 312 |
ASTM A709/A709M A709 Grade 345 Type 4 Material Thermal Properties
The thermal performance parameters of the ASTM A709/A709M A709 Grade 345 Type 4 steel are as follows:
| Temperature (°C) | 42 | 926 | 983 |
| Modulus of elasticity (GPa) | - | 824 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 14 |
| Thermal conductivity (W/m·°C) | - | 12.3 | 24.2 |
| Specific thermal capacity (J/kg·°C) | - | 121 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.22 | - | - |
| Deity (kg/dm³) | - | - | 141 |
| Poisson’s coefficient, ν | - | - | 222 |