GB/T 714 Q420qNHD Introduce

GB/T 714 Q420qNHD Steel is a metal alloy composed primarily of iron, carbon, and other elements such as manganese, phosphorus, sulfur, and silicon. Steel has a broad range of applications, from construction to machine parts, due to its strength, durability, and ability to be formed into various shapes and sizes.

Smelting temperature:1957°C - 1814°C

Application:Structural steel for bridge

GB/T 714 Q420qNHD Material Chemical Composition

The chemical composition of the GB/T 714 Q420qNHD steel are as follows:

ElementMinMax
(Pcm)-0.2200
Hydrogen (H)-0.0002
Boron (B)-0.0005
Sulfur (S)-0.0150
PhOsphorus (P)-0.0250
(Nb+V+Ti)-0.2200
Aluminum (Al)0.01500.0500
Nitrogen (N)-0.0080
Molybdenum (Mo)-0.2000
Copper (Cu)0.25000.5000
Nickel (Ni)0.30000.4000
Chromium (Cr)0.40000.7000
Titanium (Ti)0.00600.0300
Vanadium (V)0.01000.1000
Niobium (Nb)0.01000.1000
Manganese (Mn)1.10001.5000
Silicon (Si)0.15000.5000
Carbon (C)-0.1100

GB/T 714 Q420qNHD Material Mechanical Properties

The mechanical properties of the GB/T 714 Q420qNHD steel are as follows:

YieldRp0.2 ≤ 191 (MPa)
TeileRm≤ 841 (MPa)
ImpactKV/Ku21(J)
ElongationA22%
Reduction in cross section on fractureZ24%
As-Heat-Treated ConditionSolution and Aging, Annealing, Ausaging, Q+T,etc
Brinell hardness (HBW)211

GB/T 714 Q420qNHD Material Thermal Properties

The thermal performance parameters of the GB/T 714 Q420qNHD steel are as follows:

Temperature (°C)23243576
Modulus of elasticity (GPa)-452-
Mean coefficient of thermal expaion ×10-6/(°C)--13
Thermal conductivity (W/m·°C)-33.314.2
Specific thermal capacity (J/kg·°C)-213-
Specific electrical resistivity (Ω mm²/m)0.13--
Deity (kg/dm³)--114
Poisson’s coefficient, ν--433