ASTM A790/A790M Grade 690W Type A Introduce
The ASTM A790/A790M steel standard outlines specific requirements for welding duplex and stainless steel pipes and fittings. It specifies applicable welding techniques, joint design and thickness, welding procedure specifications, welding related nondestructive examination and weld acceptance criteria. The standard requires that the welding techniques and procedures used must be suitable for the application and are capable of producing a suitable weld.
Smelting temperature:1269°C - 1257°C
Application:Seamless and welded ferritic/austenitic stainless steel tube
ASTM A790/A790M Grade 690W Type A Material Chemical Composition
The chemical composition of the ASTM A790/A790M Grade 690W Type A steel are as follows:
| Element | Min | Max |
|---|---|---|
| Zirconium (Zr) | 0.0500 | 0.1500 |
| Silicon (Si) | 0.4000 | 0.8000 |
| Sulfur (S) | - | 0.0350 |
| PhOsphorus (P) | - | 0.0350 |
| Molybdenum (Mo) | 0.1800 | 0.2800 |
| Manganese (Mn) | 0.8000 | 1.1000 |
| Chromium (Cr) | 0.5000 | 0.8000 |
| Carbon (C) | 0.1500 | 0.2100 |
| Boron (B) | - | 0.0025 |
ASTM A790/A790M Grade 690W Type A Material Mechanical Properties
ASTM A790/A790M Grade 690W Type A steel has excellent corrosion resistance when exposed to aggressive, corrosive environments. This makes it a valuable choice for applications such as marine structures, chemical processing and food processing. The material is typically resistant to chlorides, sulfates and organic acids, making it suitable for a variety of different industrial environments.
The mechanical properties of the ASTM A790/A790M Grade 690W Type A steel are as follows:
| YieldRp0.2 | ≤ 631 (MPa) |
| TeileRm | ≤ 396 (MPa) |
| ImpactKV/Ku | 44(J) |
| ElongationA | 24% |
| Reduction in cross section on fractureZ | 11% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 221 |
ASTM A790/A790M Grade 690W Type A Material Thermal Properties
The thermal performance parameters of the ASTM A790/A790M Grade 690W Type A steel are as follows:
| Temperature (°C) | 11 | 164 | 864 |
| Modulus of elasticity (GPa) | - | 159 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 13 |
| Thermal conductivity (W/m·°C) | - | 42.3 | 24.2 |
| Specific thermal capacity (J/kg·°C) | - | 211 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.13 | - | - |
| Deity (kg/dm³) | - | - | 222 |
| Poisson’s coefficient, ν | - | - | 441 |
ASTM A790/A790M Grade 690W Type A Material Machining Technology
When machining ASTM A790/A790M Grade 690W Type A steel, there are several key factors to consider in order to ensure successful machining. The type of machining process, the type of cutting tool, the type of coolant, and the feed and speed are all important considerations that can have an effect on the accuracy and quality of the machining operation. By selecting the correct combination of these variables, it is possible to produce quality, precision parts and components with ASTM A790/A790M Grade 690W Type A steel.