ASTM A709/A709M Grade 690 Type M Introduce
Standard ASTM A709/A709M steel covers high strength, low-alloy structural steel shapes, plates and bars. ASTM A709/A709M steel comes in a variety of grades, from the general purpose A709 Grades 36 and 50, to the higher-strength A709 Grades HPS 70W and 100, with added copper and nickel to improve the corrosion resistance of the material. The ASTM A709/A709M steel standard also offers several grades that include higher-strength, normalized grades (A709 Grades HPS 50W/HPS 70W/HPS 100W) for applications requiring enhanced toughness and corrosion resistance.
Smelting temperature:1986°C - 1984°C
Application:Structural steel for bridge
ASTM A709/A709M Grade 690 Type M Material Chemical Composition
The chemical composition of the ASTM A709/A709M Grade 690 Type M steel are as follows:
| Element | Min | Max |
|---|---|---|
| Boron (B) | 0.0010 | 0.0050 |
| Molybdenum (Mo) | 0.4500 | 0.6000 |
| Nickel (Ni) | 1.2000 | 1.5000 |
| PhOsphorus (P) | - | 0.0350 |
| Sulfur (S) | - | 0.0350 |
| Manganese (Mn) | 0.4500 | 0.7000 |
| Silicon (Si) | 0.2000 | 0.3500 |
| Carbon (C) | 0.1200 | 0.2100 |
ASTM A709/A709M Grade 690 Type M Material Mechanical Properties
Tensile strength is a measure of the maximum load applied to an object before it deforms, breaks, or is otherwise mechanically stressed. ASTM A709/A709M Grade 690 Type M steel has an exceptional combination of high strength and ductility, allowing it to withstand heavy loads without fracturing or losing shape. The tensile strength of the steel ranges from 485MPa to 620MPa, depending on the grade and alloy combination.
The mechanical properties of the ASTM A709/A709M Grade 690 Type M steel are as follows:
| YieldRp0.2 | ≤ 619 (MPa) |
| TeileRm | ≤ 568 (MPa) |
| ImpactKV/Ku | 42(J) |
| ElongationA | 41% |
| Reduction in cross section on fractureZ | 34% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 212 |
ASTM A709/A709M Grade 690 Type M Material Thermal Properties
The thermal performance parameters of the ASTM A709/A709M Grade 690 Type M steel are as follows:
| Temperature (°C) | 14 | 658 | 351 |
| Modulus of elasticity (GPa) | - | 488 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 31 |
| Thermal conductivity (W/m·°C) | - | 41.3 | 33.2 |
| Specific thermal capacity (J/kg·°C) | - | 214 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.34 | - | - |
| Deity (kg/dm³) | - | - | 242 |
| Poisson’s coefficient, ν | - | - | 323 |