ASTM A709/A709M Grade 50 Type 4 Introduce
The ASTM A709/A709M Grade 50 Type 4 steel standard is applicable to structural shapes, plates and bars. It is ideal for many applications including bridges and other structures where corrosion resistance and strength are critical. It can be used in harsher environments than typical low-carbon steel grades, and can often be found in marine, corrosive and shipbuilding applications.
Smelting temperature:1927°C - 1532°C
Application:Structural steel for bridge
ASTM A709/A709M Grade 50 Type 4 Material Chemical Composition
The chemical composition of the ASTM A709/A709M Grade 50 Type 4 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Silicon (Si) | 0.1500 | 0.4000 |
| Sulfur (S) | - | 0.0500 |
| PhOsphorus (P) | - | 0.0400 |
| Manganese (Mn) | - | 1.3500 |
| Copper (Cu) | - | 0.1800 |
| Carbon (C) | - | 0.2300 |
ASTM A709/A709M Grade 50 Type 4 Material Mechanical Properties
Yield strength is the maximum stress which an object can withstand before it is no longer able to return to its original shape. ASTM A709/A709M Grade 50 Type 4 steel has a high yield strength, ranging from 380MPa to 690MPa, depending on the grade and alloy combination. This allows the steel to withstand tremendous loads without permanently deforming or losing strength.
The mechanical properties of the ASTM A709/A709M Grade 50 Type 4 steel are as follows:
| YieldRp0.2 | ≤ 387 (MPa) |
| TeileRm | ≤ 777 (MPa) |
| ImpactKV/Ku | 43(J) |
| ElongationA | 14% |
| Reduction in cross section on fractureZ | 13% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 434 |
ASTM A709/A709M Grade 50 Type 4 Material Thermal Properties
The thermal performance parameters of the ASTM A709/A709M Grade 50 Type 4 steel are as follows:
| Temperature (°C) | 31 | 178 | 988 |
| Modulus of elasticity (GPa) | - | 193 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 21 |
| Thermal conductivity (W/m·°C) | - | 22.3 | 31.2 |
| Specific thermal capacity (J/kg·°C) | - | 441 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.41 | - | - |
| Deity (kg/dm³) | - | - | 142 |
| Poisson’s coefficient, ν | - | - | 142 |