GB/T 699 U20702 Introduce
Steel is one of the most widely used materials in the world, used for a variety of applications from construction to transportation. GB/T 699 U20702 is a popular alloy steel used for a variety of purposes, from precision machining to general engineering use. GB/T 699 U20702 is an alloy which is made up of two different types of steel: high-carbon steel and low-carbon steel. The high-carbon steel is used for the formation of the "matrix" of the metal; this contains the majority of the chemical elements listed above. The low-carbon steel is added for strength and is found mainly in the "alloying" elements. This combination of high-carbon and low-carbon steel creates a metal that is stronger and more durable than either type of steel alone.
Smelting temperature:1589°C - 1121°C
Application:High quality carbon structural steel
GB/T 699 U20702 Material Chemical Composition
The chemical composition of the GB/T 699 U20702 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Carbon (C) | 0.6700 | 0.7500 |
| Silicon (Si) | 0.1700 | 0.3700 |
| Manganese (Mn) | 0.5000 | 0.8000 |
| PhOsphorus (P) | - | 0.0350 |
| Sulfur (S) | - | 0.0350 |
| Chromium (Cr) | - | 0.2500 |
| Nickel (Ni) | - | 0.3000 |
| Copper (Cu) | - | 0.2500 |
| Copper (Cu) | - | 0.2500 |
| Chromium (Cr) | - | 0.2000 |
GB/T 699 U20702 Material Mechanical Properties
The mechanical properties of the GB/T 699 U20702 steel are as follows:
| YieldRp0.2 | ≤ 127 (MPa) |
| TeileRm | ≤ 579 (MPa) |
| ImpactKV/Ku | 43(J) |
| ElongationA | 22% |
| Reduction in cross section on fractureZ | 32% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 211 |
GB/T 699 U20702 Material Thermal Properties
The thermal performance parameters of the GB/T 699 U20702 steel are as follows:
| Temperature (°C) | 43 | 469 | 465 |
| Modulus of elasticity (GPa) | - | 546 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 24 |
| Thermal conductivity (W/m·°C) | - | 21.3 | 32.2 |
| Specific thermal capacity (J/kg·°C) | - | 124 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.23 | - | - |
| Deity (kg/dm³) | - | - | 442 |
| Poisson’s coefficient, ν | - | - | 144 |
GB/T 699 U20702 Material Machining Technology
Machining of GB/T 699 U20702 steel typically requires a combination of diverse machining processes for quality production of more complex components. China being the biggest steel producers in the world, manufactures and supplies GB/T 699 U20702 steel, which is a high-quality carbon structural steel. This type of steel is machinable and is suitable for the manufacture of automotive parts, machine tools, and many other machines. Typically, GB/T 699 U20702 steel is used extensively in the manufacture of machinery and tools, as it is strong, durable and has excellent corrosion resistance.