SAE J1268 AISI 4340H Introduce
Steel is one of the most common materials used in a variety of construction projects, as it is readily available, strong, and durable. Various types of steel offer different mechanical and physical properties, such as ductility, strength, weldability and corrosion resistance. SAE J1268 AISI 4340H steel is a low-carbon steel alloy that contains a range of other elements, such as manganese and chromium, that work to improve its strength and ductility. These elements also add to the steel's corrosion resistance. On its own, low-carbon steel is prone to corrosion when exposed to environmental factors, so adding other alloying elements can help protect the steel from rust and other forms of corrosion.
Smelting temperature:1188°C - 1587°C
Application:Hardenability bands for carbon and alloy H steels
SAE J1268 AISI 4340H Material Chemical Composition
The chemical composition of the SAE J1268 AISI 4340H steel are as follows:
| Element | Min | Max |
|---|---|---|
| Silicon (Si) | 0.1500 | 0.3500 |
| Sulfur (S) | - | 0.0400 |
| PhOsphorus (P) | - | 0.0300 |
| Nickel (Ni) | 1.5500 | 2.0000 |
| Molybdenum (Mo) | 0.2000 | 0.3000 |
| Manganese (Mn) | 0.5500 | 0.9000 |
| Copper (Cu) | - | 0.3500 |
| Chromium (Cr) | 0.6500 | 0.9500 |
| Carbon (C) | 0.3700 | 0.4400 |
SAE J1268 AISI 4340H Material Mechanical Properties
The mechanical properties of the SAE J1268 AISI 4340H steel are as follows:
| YieldRp0.2 | ≤ 275 (MPa) |
| TeileRm | ≤ 766 (MPa) |
| ImpactKV/Ku | 42(J) |
| ElongationA | 14% |
| Reduction in cross section on fractureZ | 12% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 432 |
SAE J1268 AISI 4340H Material Thermal Properties
The thermal performance parameters of the SAE J1268 AISI 4340H steel are as follows:
| Temperature (°C) | 11 | 435 | 982 |
| Modulus of elasticity (GPa) | - | 453 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 34 |
| Thermal conductivity (W/m·°C) | - | 31.3 | 11.2 |
| Specific thermal capacity (J/kg·°C) | - | 144 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.32 | - | - |
| Deity (kg/dm³) | - | - | 113 |
| Poisson’s coefficient, ν | - | - | 234 |