ASTM A684/A684M 1055 Introduce
ASTM A684/A684M 1055 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 1055 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:1798°C - 1281°C
Application:Cold rolled high carbon steel strip
ASTM A684/A684M 1055 Material Chemical Composition
The chemical composition of the ASTM A684/A684M 1055 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Carbon (C) | 0.5000 | 0.6000 |
| 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 1055 Material Mechanical Properties
One of the major advantages of ASTM A684/A684M 1055 steel is its corrosion resistance. Increased chromium and molybdenum contents make the steel more resistant to corrosion in different environments, including salt water and certain acidic solutions. Chromium forms a protective oxide layer on the surface of the steel, which helps to prevent further corrosion. The nickel content also improves corrosion resistance, making it a great choice for marine applications.
The mechanical properties of the ASTM A684/A684M 1055 steel are as follows:
| YieldRp0.2 | ≤ 734 (MPa) |
| TeileRm | ≤ 298 (MPa) |
| ImpactKV/Ku | 32(J) |
| ElongationA | 43% |
| Reduction in cross section on fractureZ | 42% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 114 |
ASTM A684/A684M 1055 Material Thermal Properties
The thermal performance parameters of the ASTM A684/A684M 1055 steel are as follows:
| Temperature (°C) | 11 | 585 | 617 |
| Modulus of elasticity (GPa) | - | 493 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 32 |
| Thermal conductivity (W/m·°C) | - | 33.3 | 12.2 |
| Specific thermal capacity (J/kg·°C) | - | 313 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.23 | - | - |
| Deity (kg/dm³) | - | - | 213 |
| Poisson’s coefficient, ν | - | - | 341 |
ASTM A684/A684M 1055 Material Machining Technology
The mechanical properties of ASTM A684/A684M 1055 steel must meet the requirements specified in the following table. The material is designed for Structural, Bridge and Pressure Vessel applications. The material is required to meet specific strengths, elongation, yield strength, and toughness requirements to ensure reliable performance in its application.