GB/T 1299 SM55 Introduce
GB/T 1299 SM55 steel is an alloy of iron and carbon, with production and use stretching back thousands of years. Steel can also contain other elements such as silicon and manganese, as well as trace elements such as cobalt and chromium. When it comes to commercial steel, however, one of the most commonly used and specified grades is GB/T 1299 SM55 steel.
Smelting temperature:1929°C - 1764°C
Application:Alloy tool steel
GB/T 1299 SM55 Material Chemical Composition
The chemical composition of the GB/T 1299 SM55 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Nickel (Ni) | - | 0.2500 |
| Chromium (Cr) | - | 0.2500 |
| Copper (Cu) | - | 0.2500 |
| Sulfur (S) | - | 0.0250 |
| PhOsphorus (P) | - | 0.0250 |
| Manganese (Mn) | 0.5000 | 0.8000 |
| Silicon (Si) | 0.1700 | 0.3700 |
| Carbon (C) | 0.5200 | 0.5800 |
GB/T 1299 SM55 Material Mechanical Properties
GB/T 1299 SM55 steel is used in almost every branch of industry due to its unique combination of mechanical and physical properties. GB/T 1299 SM55 Grade steel is one such variety that is used particularly in the construction industry. It has excellent mechanical properties, such as high strength and ductility, and can be used in a wide variety of applications.
The mechanical properties of the GB/T 1299 SM55 steel are as follows:
| YieldRp0.2 | ≤ 321 (MPa) |
| TeileRm | ≤ 963 (MPa) |
| ImpactKV/Ku | 24(J) |
| ElongationA | 24% |
| Reduction in cross section on fractureZ | 24% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 333 |
GB/T 1299 SM55 Material Thermal Properties
The thermal performance parameters of the GB/T 1299 SM55 steel are as follows:
| Temperature (°C) | 33 | 915 | 563 |
| Modulus of elasticity (GPa) | - | 413 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 44 |
| Thermal conductivity (W/m·°C) | - | 23.3 | 14.2 |
| Specific thermal capacity (J/kg·°C) | - | 342 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.31 | - | - |
| Deity (kg/dm³) | - | - | 131 |
| Poisson’s coefficient, ν | - | - | 311 |