ASTM A656/A656M A656 Type 7 Grade 70 Introduce
ASTM A656/A656M A656 Type 7 Grade 70 covers the chemical composition of the alloy, which specifies the appropriate chemical balance that must be present in the product. This balance ensures that the products from different suppliers have similar properties and characteristics. The mechanical properties that the product must meet are defined in the last part such as the required specified yield strengths and tensile strength.
Smelting temperature:1688°C - 1447°C
Application:High-strength low-alloy hot-rolled structural steel plate with improved forgeability
ASTM A656/A656M A656 Type 7 Grade 70 Material Chemical Composition
The chemical composition of the ASTM A656/A656M A656 Type 7 Grade 70 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Carbon (C) | - | 0.1800 |
| Manganese (Mn) | - | 1.6500 |
| PhOsphorus (P) | - | 0.0250 |
| Sulfur (S) | - | 0.0300 |
| Silicon (Si) | - | 0.6000 |
| Vanadium (V) | - | 0.1500 |
| Nitrogen (N) | - | 0.0300 |
| Niobium (Nb) | - | 0.1000 |
| Sulfur (S) | - | 0.0350 |
| Niobium (Nb) | - | 0.1000 |
ASTM A656/A656M A656 Type 7 Grade 70 Material Mechanical Properties
Tensile strength is the maximum stress that can be applied to a material before it yields or breaks. It is also an indication of a material's ductility; the higher the tensile strength, the more ductile a material is considered to be. The minimum specified tensile strength for ASTM A656/A656M A656 Type 7 Grade 70 steel is 150 ksi. This yields the material with excellent formability and makes it suitable for applications subject to high stress levels.
The mechanical properties of the ASTM A656/A656M A656 Type 7 Grade 70 steel are as follows:
| YieldRp0.2 | ≤ 793 (MPa) |
| TeileRm | ≤ 734 (MPa) |
| ImpactKV/Ku | 33(J) |
| ElongationA | 22% |
| Reduction in cross section on fractureZ | 43% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 221 |
ASTM A656/A656M A656 Type 7 Grade 70 Material Thermal Properties
The thermal performance parameters of the ASTM A656/A656M A656 Type 7 Grade 70 steel are as follows:
| Temperature (°C) | 33 | 192 | 277 |
| Modulus of elasticity (GPa) | - | 833 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 34 |
| Thermal conductivity (W/m·°C) | - | 34.3 | 43.2 |
| Specific thermal capacity (J/kg·°C) | - | 322 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.14 | - | - |
| Deity (kg/dm³) | - | - | 234 |
| Poisson’s coefficient, ν | - | - | 334 |
ASTM A656/A656M A656 Type 7 Grade 70 Material Machining Technology
ASTM A656/A656M A656 Type 7 Grade 70 is highly formable and can be readily welded, machined, and cold worked. It easily bends, curves, and can be cut to the required size and shape. It is possible that an increased amount of formability may be available in ASTM A656/A656M A656 Type 7 Grade 70 as compared to standard carbon steels.