ASTM A240/A240M A240 Type 304N Introduce
ASTM A240/A240M A240 Type 304N provides the requirements for a wide range of products, ranging from general purpose to stress relieved pressure vessels and related components. It also provides requirements for flat-rolled and cold-rolled sheet, strip and strip-maps, coils, and plates. The specification includes requirements for chemical composition, surface quality, final heat treatment, physical and mechanical properties, heat-resistance, shop surface finishing, and packaging.
Smelting temperature:1989°C - 1286°C
Application:Heat-resistant chrome and chrome-nickel stainless steel sheets, sheets and strips for pressure vessels
ASTM A240/A240M A240 Type 304N Material Mechanical Properties
The chromium and nickel content of ASTM A240/A240M A240 Type 304N steel gives it increased corrosion resistance, while the molybdenum gives it improved ductility and improved heat and oxidation resistance. The nitrogen content helps to increase its strength.
The mechanical properties of the ASTM A240/A240M A240 Type 304N steel are as follows:
| YieldRp0.2 | ≤ 612 (MPa) |
| TeileRm | ≤ 144 (MPa) |
| ImpactKV/Ku | 24(J) |
| ElongationA | 14% |
| Reduction in cross section on fractureZ | 34% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 412 |
ASTM A240/A240M A240 Type 304N Material Thermal Properties
The thermal performance parameters of the ASTM A240/A240M A240 Type 304N steel are as follows:
| Temperature (°C) | 22 | 449 | 574 |
| Modulus of elasticity (GPa) | - | 182 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 14 |
| Thermal conductivity (W/m·°C) | - | 33.3 | 11.2 |
| Specific thermal capacity (J/kg·°C) | - | 232 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.22 | - | - |
| Deity (kg/dm³) | - | - | 242 |
| Poisson’s coefficient, ν | - | - | 232 |
ASTM A240/A240M A240 Type 304N Material Machining Technology
ASTM A240/A240M A240 Type 304N steel is more difficult to work with due to its high temperature strength, low ductility, and high yield strength. When machining, the tool must be sharp, and a wider cutting edge must be used to avoid tool failure. Additionally, stainless steel is not suitable for welding, as it requires special procedures to prevent cracking or corrosion.