ASTM A656/A656M 550-Ⅲ Introduce

ASTM A656/A656M 550-Ⅲ is an American Society for Testing and Materials (ASTM) steel standard that defines the properties of hot-rolled structural steel, high-strength low-alloy plates, and quenched and tempered alloy plates used in the construction of bridges and buildings. The standard is composed of three major parts, product specifications, chemical composition, and mechanical properties. ASTM A656/A656M 550-Ⅲ steel is used to make high-strength steel plates and components for building structures, mining equipment, industrial tools and storage tanks. Tests are conducted to verify the mechanical properties, such as the yield strength, tensile strength, and elongation of ASTM A656/A656M 550-Ⅲ steel.

Smelting temperature:1652°C - 1496°C

Application:High-strength low-alloy hot-rolled structural steel plate with improved forgeability

ASTM A656/A656M 550-Ⅲ Material Chemical Composition

The chemical composition of the ASTM A656/A656M 550-Ⅲ steel are as follows:

ElementMinMax
Copper (Cu)0.00800.1000
Vanadium (V)-0.0800
Nickel (Ni)-0.0200
PhOsphorus (P)-0.0250
Sulfur (S)-0.0350
Manganese (Mn)-1.6500
Silicon (Si)-0.6000
Carbon (C)-0.1800
Niobium (Nb)0.00500.1500

ASTM A656/A656M 550-Ⅲ 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 550-Ⅲ 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 550-Ⅲ steel are as follows:

YieldRp0.2 ≤ 613 (MPa)
TeileRm≤ 163 (MPa)
ImpactKV/Ku41(J)
ElongationA22%
Reduction in cross section on fractureZ31%
As-Heat-Treated ConditionSolution and Aging, Annealing, Ausaging, Q+T,etc
Brinell hardness (HBW)311

ASTM A656/A656M 550-Ⅲ Material Thermal Properties

The thermal performance parameters of the ASTM A656/A656M 550-Ⅲ steel are as follows:

Temperature (°C)41366371
Modulus of elasticity (GPa)-788-
Mean coefficient of thermal expaion ×10-6/(°C)--24
Thermal conductivity (W/m·°C)-41.331.2
Specific thermal capacity (J/kg·°C)-112-
Specific electrical resistivity (Ω mm²/m)0.12--
Deity (kg/dm³)--344
Poisson’s coefficient, ν--221

ASTM A656/A656M 550-Ⅲ Material Machining Technology

Machining ASTM A656/A656M 550-Ⅲ steel requires the use of specialized cutting tools and processes. Cutting tools must be selected carefully, and cutting parameters should be optimized for the application at hand. Additionally, machinability of ASTM A656/A656M 550-Ⅲ steel can be improved through appropriate cutting fluid, heat treatments, and chip control. In summary, machining ASTM A656/A656M 550-Ⅲ steel requires a great deal of skill and experience in order to be successful.