GB 713 Q420R Introduce
GB 713 Q420R is a special steel grade designed and manufactured by the China Iron and Steel Research Institute Group (CISRI). It is a medium carbon structural steel usually applied in boiler and pressure vessels. GB 713 Q420R is a kind of low alloy steel, which is characterized by high strength, good ductility and resistance to corrosion. It also has a low thermal expansion coefficient, good toughness and high hardness. This steel is also well known for its excellent welding performance and its convenience for machining.
Smelting temperature:1752°C - 1297°C
Application:Steel plate for boiler
GB 713 Q420R Material Chemical Composition
The chemical composition of the GB 713 Q420R steel are as follows:
| Element | Min | Max |
|---|---|---|
| Sulfur (S) | - | 0.0100 |
| PhOsphorus (P) | - | 0.0200 |
| Titanium (Ti) | - | 0.0300 |
| Vanadium (V) | - | 0.1000 |
| Niobium (Nb) | 0.0150 | 0.0500 |
| Molybdenum (Mo) | - | 0.0800 |
| Chromium (Cr) | - | 0.3000 |
| Nickel (Ni) | 0.2000 | 0.5000 |
| Copper (Cu) | - | 0.3000 |
| Manganese (Mn) | 1.3000 | 1.7000 |
| Silicon (Si) | - | 0.5500 |
| Carbon (C) | - | 0.2000 |
GB 713 Q420R Material Mechanical Properties
The mechanical properties of the GB 713 Q420R steel are as follows:
| YieldRp0.2 | ≤ 139 (MPa) |
| TeileRm | ≤ 287 (MPa) |
| ImpactKV/Ku | 22(J) |
| ElongationA | 12% |
| Reduction in cross section on fractureZ | 14% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 211 |
GB 713 Q420R Material Thermal Properties
The thermal performance parameters of the GB 713 Q420R steel are as follows:
| Temperature (°C) | 23 | 868 | 415 |
| Modulus of elasticity (GPa) | - | 738 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 34 |
| Thermal conductivity (W/m·°C) | - | 13.3 | 21.2 |
| Specific thermal capacity (J/kg·°C) | - | 323 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.41 | - | - |
| Deity (kg/dm³) | - | - | 213 |
| Poisson’s coefficient, ν | - | - | 332 |