ASTM A684/A684M 1065 Introduce
ASTM A684/A684M 1065 was first published in 1985 and is an evolution of earlier standards, including AASHTO 2024 (1974) and ASTM A36 (1980). The new standard was approved in 2000 and is now known as ASTM A684/A684M. The difference between ASTM A36 and ASTM A684/A684M is the amount of manganese, which increases the steel's strength and resistance to ductile fracture. ASTM A684/A684M 1065 covers the requirements for high-strength carbon-manganese-silicon steel plates, shapes and bars designed for structural, pressure vessel and bridge applications. It is applicable to both hot-rolled and cold-finished steel specimens.
Smelting temperature:1741°C - 1151°C
Application:Cold rolled high carbon steel strip
ASTM A684/A684M 1065 Material Chemical Composition
The chemical composition of the ASTM A684/A684M 1065 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Carbon (C) | 0.6000 | 0.7000 |
| Manganese (Mn) | 0.6000 | 0.9000 |
| PhOsphorus (P) | - | 0.0300 |
| Sulfur (S) | - | 0.0350 |
| Silicon (Si) | 0.1500 | 0.3000 |
| Nickel (Ni) | - | 0.3000 |
| Chromium (Cr) | - | 0.2500 |
| Molybdenum (Mo) | - | 0.1000 |
| Copper (Cu) | - | 0.3000 |
| (Cr+Ni+Cu+Mo) | - | 0.8000 |
| Silicon (Si) | 0.1500 | 0.3000 |
| Nickel (Ni) | - | 0.3000 |
| Molybdenum (Mo) | - | 0.1000 |
| Copper (Cu) | - | 0.3000 |
| Chromium (Cr) | - | 0.2500 |
ASTM A684/A684M 1065 Material Mechanical Properties
Heat treatment is often used to improve the hardness and tensile strength of ASTM A684/A684M 1065 steel. It is normally done by heating the steel to a specific temperature and then cooling it quickly. The cool down process can be done in air or by quenching, which involves submerging the sample in a liquid coolant. The heat treatment increases the toughness, wear resistance and fatigue strength of the material.
The mechanical properties of the ASTM A684/A684M 1065 steel are as follows:
| YieldRp0.2 | ≤ 943 (MPa) |
| TeileRm | ≤ 986 (MPa) |
| ImpactKV/Ku | 41(J) |
| ElongationA | 42% |
| Reduction in cross section on fractureZ | 41% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 233 |
ASTM A684/A684M 1065 Material Thermal Properties
The thermal performance parameters of the ASTM A684/A684M 1065 steel are as follows:
| Temperature (°C) | 12 | 947 | 647 |
| Modulus of elasticity (GPa) | - | 127 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 42 |
| Thermal conductivity (W/m·°C) | - | 31.3 | 33.2 |
| Specific thermal capacity (J/kg·°C) | - | 432 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.14 | - | - |
| Deity (kg/dm³) | - | - | 122 |
| Poisson’s coefficient, ν | - | - | 134 |
ASTM A684/A684M 1065 Material Machining Technology
Another advantage of machining ASTM A684/A684M 1065 steel is that it does not require excessive amounts of heat for the process. The low melting point of the metal makes it easy to cut with mechanical tools instead of heat-based techniques, which can save time, resources and money.