GB/T 1591 Q420B Introduce
GB/T 1591 has brought about unified production standards and made it easier for consumers to compare different steel products. This improves communication between manufacturers and consumers and helps to build a fair market. It is expected that the implementation of GB/T 1591 will bring further economic and environmental benefits to China's steel industry.
Smelting temperature:1769°C - 1572°C
Application:Low alloy high strength structural steel
GB/T 1591 Q420B Material Chemical Composition
The chemical composition of the GB/T 1591 Q420B steel are as follows:
| Element | Min | Max |
|---|---|---|
| Carbon (C) | - | 0.2000 |
| Silicon (Si) | - | 0.5000 |
| Manganese (Mn) | - | 1.7000 |
| PhOsphorus (P) | - | 0.0350 |
| Sulfur (S) | - | 0.0350 |
| Niobium (Nb) | - | 0.0700 |
| Vanadium (V) | - | 0.2000 |
| Titanium (Ti) | - | 0.2000 |
| Chromium (Cr) | - | 0.3000 |
| Nickel (Ni) | - | 0.8000 |
| Copper (Cu) | - | 0.3000 |
| Nitrogen (N) | - | 0.0150 |
| Molybdenum (Mo) | - | 0.2000 |
GB/T 1591 Q420B Material Mechanical Properties
GB/T 1591 Q420B steels are high-strength structural steel grades developed by China. The mechanical properties of these steels are heavily influenced by the grade and chemical composition of the material. Carbon, copper, manganese and phosphorus are important elements when considering the strength and hardness of the steel, while chromium, nickel and molybdenum are important when considering corrosion resistance. The weldability of the steel is also affected by the level of carbon, phosphorus and sulfur in the material. The elasticity, strength, toughness, fatigue strength and wear resistance of GB/T 1591 Q420B steels are all important properties when selecting the most suitable material for an application.
The mechanical properties of the GB/T 1591 Q420B steel are as follows:
| YieldRp0.2 | ≤ 945 (MPa) |
| TeileRm | ≤ 689 (MPa) |
| ImpactKV/Ku | 34(J) |
| ElongationA | 32% |
| Reduction in cross section on fractureZ | 13% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 331 |
GB/T 1591 Q420B Material Thermal Properties
The thermal performance parameters of the GB/T 1591 Q420B steel are as follows:
| Temperature (°C) | 41 | 462 | 144 |
| Modulus of elasticity (GPa) | - | 521 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 33 |
| Thermal conductivity (W/m·°C) | - | 43.3 | 12.2 |
| Specific thermal capacity (J/kg·°C) | - | 432 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.21 | - | - |
| Deity (kg/dm³) | - | - | 442 |
| Poisson’s coefficient, ν | - | - | 114 |
GB/T 1591 Q420B Material Machining Technology
In addition to its excellent performance, GB/T 1591 Q420B also provides good weldability. Under the same conditions, compared with other steels, GB/T 1591 Q420Bs are required to use smaller welding rods. Therefore, the cost is lower. GB/T 1591 Q420B is a kind of high-performance alloy steel. Its excellent performance makes it widely used in various industries and can reduce the cost of use. Therefore, it is an ideal choice for large-scale projects.