ASTM A240/A240M N08904 Introduce
ASTM A240/A240M N08904 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:1164°C - 1166°C
Application:Heat-resistant chrome and chrome-nickel stainless steel sheets, sheets and strips for pressure vessels
ASTM A240/A240M N08904 Material Mechanical Properties
Due to the high chromium and nickel content, ASTM A240/A240M N08904 steel is highly resistant to corrosion and has a high level of corrosion resistance over a wide range of corrosive environments. The molybdenum content improves the corrosion resistance of the steel and prevents pitting, crevice corrosion, and stress corrosion cracking.
The mechanical properties of the ASTM A240/A240M N08904 steel are as follows:
| YieldRp0.2 | ≤ 781 (MPa) |
| TeileRm | ≤ 394 (MPa) |
| ImpactKV/Ku | 22(J) |
| ElongationA | 13% |
| Reduction in cross section on fractureZ | 34% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 213 |
ASTM A240/A240M N08904 Material Thermal Properties
The thermal performance parameters of the ASTM A240/A240M N08904 steel are as follows:
| Temperature (°C) | 42 | 655 | 733 |
| Modulus of elasticity (GPa) | - | 574 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 34 |
| Thermal conductivity (W/m·°C) | - | 23.3 | 42.2 |
| Specific thermal capacity (J/kg·°C) | - | 133 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.41 | - | - |
| Deity (kg/dm³) | - | - | 213 |
| Poisson’s coefficient, ν | - | - | 421 |
ASTM A240/A240M N08904 Material Machining Technology
When machining ASTM A240/A240M N08904 steel, chip formation should be monitored closely to ensure that no warping or surface defects occur. Chip breakers may be used to help reduce chip formation, while depth of cut, feed rate, and cutting speed should all be set to minimize the load applied to the tool.