ASTM A312/A312M Type 348 Introduce
ASTM A312/A312M is an international standard for seamless, welded, and heavily cold worked austenitic stainless steel pipes. It defines the chemical, mechanical, and metallurgical properties of the steel, along with the required physical and test results for standard pipes. The standard, which was first released in 2001, is published by the American Society for Testing and Materials (ASTM).
Smelting temperature:1392°C - 1155°C
Application:Seamless and welded austenitic stainless steel tube
ASTM A312/A312M Type 348 Material Chemical Composition
The chemical composition of the ASTM A312/A312M Type 348 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Tantalum (Ta) | - | 0.1000 |
| Silicon (Si) | - | 1.0000 |
| Sulfur (S) | - | 0.0300 |
| PhOsphorus (P) | - | 0.0450 |
| Nickel (Ni) | 9.0000 | 13.0000 |
| Niobium (Nb) | - | 1.0000 |
| Manganese (Mn) | - | 2.0000 |
| Chromium (Cr) | 17.0000 | 19.0000 |
| Carbon (C) | - | 0.0800 |
ASTM A312/A312M Type 348 Material Mechanical Properties
The mechanical properties of ASTM A312/A312M Type 348 stainless steel pipe are essential in determining the strength, ductility, and toughness of the material. The three main mechanical properties of this material are its yield strength, tensile strength, and modulus of elasticity. The minimum required yield strength of these pipes is 0.2% of the specified ultimate tensile strength, the minimum required ultimate tensile strength is 65 Ksi (448 MPa), and the minimum required modulus of elasticity is 29,000 ksi (200,000 MPa).
The mechanical properties of the ASTM A312/A312M Type 348 steel are as follows:
| YieldRp0.2 | ≤ 326 (MPa) |
| TeileRm | ≤ 268 (MPa) |
| ImpactKV/Ku | 11(J) |
| ElongationA | 14% |
| Reduction in cross section on fractureZ | 43% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 223 |
ASTM A312/A312M Type 348 Material Thermal Properties
The thermal performance parameters of the ASTM A312/A312M Type 348 steel are as follows:
| Temperature (°C) | 34 | 315 | 748 |
| Modulus of elasticity (GPa) | - | 468 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 32 |
| Thermal conductivity (W/m·°C) | - | 34.3 | 31.2 |
| Specific thermal capacity (J/kg·°C) | - | 322 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.44 | - | - |
| Deity (kg/dm³) | - | - | 331 |
| Poisson’s coefficient, ν | - | - | 422 |
ASTM A312/A312M Type 348 Material Machining Technology
Machining ASTM A312/A312M Type 348 steel is a complex process, but it can be highly rewarding if done correctly. The key to success is to select the right tools and cutting strategies, employ coolant strategies to reduce heat generation and tool wear, and utilize the right finishing techniques to achieve the desired surface quality. With experience and knowledge of how to best work with this special type of steel, skilled machinists can produce high-quality parts and components from ASTM A312/A312M Type 348 steel.