GB/T 3077 A20402 Introduce
GB/T 3077 A20402 is one of the most commonly used Chinese structural steels especially for low to medium strength applications. It is well suited for hot forming and cold forming, and it is often used for medium strength mechanical parts. Its tensile strength is from 370 to 500MPa and yield strength from 310 to 390MPa. GB/T 3077 A20402 is widely used for the production of hot rolled steels for machine building, brakes and press components, crankshafts, gears, shafts for engines, hydraulic power units and parts for oil-field industry. It is also suitable for manufacturing heat-resistant parts, vehicle load components, shafts, and such.
Smelting temperature:1711°C - 1287°C
Application:Alloy structural steel
GB/T 3077 A20402 Material Chemical Composition
The chemical composition of the GB/T 3077 A20402 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Silicon (Si) | 0.1700 | 0.3700 |
| Sulfur (S) | - | 0.0350 |
| PhOsphorus (P) | - | 0.0350 |
| Nickel (Ni) | - | 0.3000 |
| Molybdenum (Mo) | - | 0.1500 |
| Manganese (Mn) | 0.5000 | 0.8000 |
| Copper (Cu) | - | 0.2000 |
| Chromium (Cr) | 0.8000 | 1.1000 |
| Carbon (C) | 0.3700 | 0.4400 |
| Copper (Cu) | - | 0.3000 |
GB/T 3077 A20402 Material Mechanical Properties
The mechanical properties of GB/T 3077 A20402 steel, hardness, impact resistance, and fatigue resistance.
Hardness: GB/T 3077 A20402 steel has a high hardness level, with a maximum hardness of up to HRC 58. This makes it resistant to wear and tear, and ideal for applications such as military vehicles and sheet metal components that require superior wear and abrasion resistance.
Impact resistance: GB/T 3077 A20402 steel is highly resistant to impacts caused by vibrations, temperature extremes, and impacts from dropping heavy objects. This makes it well suited for applications such as auto parts and construction components, which must be able to withstand frequent vibration or impacts without breaking or deforming.
Fatigue resistance: GB/T 3077 A20402 steel is resistant to fatigue due to its high strength-to-weight ratio. This means it can be used in applications where the steel must be able to withstand repeated cycles of loading and unloading without breaking or deforming.
The mechanical properties of the GB/T 3077 A20402 steel are as follows:
| YieldRp0.2 | ≤ 231 (MPa) |
| TeileRm | ≤ 167 (MPa) |
| ImpactKV/Ku | 41(J) |
| ElongationA | 32% |
| Reduction in cross section on fractureZ | 21% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 121 |
GB/T 3077 A20402 Material Thermal Properties
The thermal performance parameters of the GB/T 3077 A20402 steel are as follows:
| Temperature (°C) | 43 | 863 | 576 |
| Modulus of elasticity (GPa) | - | 756 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 42 |
| Thermal conductivity (W/m·°C) | - | 22.3 | 43.2 |
| Specific thermal capacity (J/kg·°C) | - | 311 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.14 | - | - |
| Deity (kg/dm³) | - | - | 113 |
| Poisson’s coefficient, ν | - | - | 134 |
GB/T 3077 A20402 Material Machining Technology
When working with GB/T 3077 A20402 steel, it is important to be aware of the materials and tools required to achieve the desired results. Generally, this type of steel is machined using standard tools, such as drills, taps, reamers, and turning tools. It can be machined using both traditional and CNC machines, including lathes and mills.