ASTM A709/A709M A709 Grade 345 Type 3 Introduce

The ASTM A709/A709M steel standard is a globally recognized specification. It is used in a wide variety of structural applications due to its superior strength and durability compared to other steels. The standard is regularly revised in order to ensure the highest quality and safety of construction materials.

Smelting temperature:1193°C - 1617°C

Application:Structural steel for bridge

ASTM A709/A709M A709 Grade 345 Type 3 Material Chemical Composition

The chemical composition of the ASTM A709/A709M A709 Grade 345 Type 3 steel are as follows:

ElementMinMax
Copper (Cu)0.2000-
Niobium (Nb)0.00500.0500
Vanadium (V)0.01000.1500
PhOsphorus (P)-0.0400
Sulfur (S)-0.0500
Manganese (Mn)-1.3500
Silicon (Si)-0.4000
Carbon (C)-0.2300
(V+Nb)0.01000.1600
Silicon (Si)0.15000.4000
Niobium (Nb)0.00400.0600
Manganese (Mn)-1.3500
Copper (Cu)-0.1800
Carbon (C)-0.2300

ASTM A709/A709M A709 Grade 345 Type 3 Material Mechanical Properties

Yield strength is the maximum stress which an object can withstand before it is no longer able to return to its original shape. ASTM A709/A709M A709 Grade 345 Type 3 steel has a high yield strength, ranging from 380MPa to 690MPa, depending on the grade and alloy combination. This allows the steel to withstand tremendous loads without permanently deforming or losing strength.

The mechanical properties of the ASTM A709/A709M A709 Grade 345 Type 3 steel are as follows:

YieldRp0.2 ≤ 725 (MPa)
TeileRm≤ 187 (MPa)
ImpactKV/Ku12(J)
ElongationA12%
Reduction in cross section on fractureZ13%
As-Heat-Treated ConditionSolution and Aging, Annealing, Ausaging, Q+T,etc
Brinell hardness (HBW)114

ASTM A709/A709M A709 Grade 345 Type 3 Material Thermal Properties

The thermal performance parameters of the ASTM A709/A709M A709 Grade 345 Type 3 steel are as follows:

Temperature (°C)22345383
Modulus of elasticity (GPa)-187-
Mean coefficient of thermal expaion ×10-6/(°C)--33
Thermal conductivity (W/m·°C)-34.311.2
Specific thermal capacity (J/kg·°C)-234-
Specific electrical resistivity (Ω mm²/m)0.23--
Deity (kg/dm³)--134
Poisson’s coefficient, ν--412