ASTM A312/A312M Type 304H Introduce
ASTM A312/A312M is an important international standard that defines the chemical, mechanical, and metallurgical properties of five types of austenitic stainless steel alloy. It helps ensure product quality and consistency, and reduces product defects and lead times. The standard is used to manufacture stainless steel pipes for a variety of applications, including heating and cooling systems, process piping, pressure vessels, and food and beverage processing equipment.
Smelting temperature:1545°C - 1566°C
Application:Seamless and welded austenitic stainless steel tube
ASTM A312/A312M Type 304H Material Chemical Composition
The chemical composition of the ASTM A312/A312M Type 304H steel are as follows:
| Element | Min | Max |
|---|---|---|
| Silicon (Si) | - | 1.0000 |
| Sulfur (S) | - | 0.0300 |
| PhOsphorus (P) | - | 0.0450 |
| Nickel (Ni) | 8.0000 | 11.0000 |
| Manganese (Mn) | - | 2.0000 |
| Chromium (Cr) | 18.0000 | 20.0000 |
| Carbon (C) | 0.0400 | 0.1000 |
ASTM A312/A312M Type 304H Material Mechanical Properties
The mechanical properties of ASTM A312/A312M Type 304H 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 304H steel are as follows:
| YieldRp0.2 | ≤ 313 (MPa) |
| TeileRm | ≤ 219 (MPa) |
| ImpactKV/Ku | 14(J) |
| ElongationA | 11% |
| Reduction in cross section on fractureZ | 32% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 143 |
ASTM A312/A312M Type 304H Material Thermal Properties
The thermal performance parameters of the ASTM A312/A312M Type 304H steel are as follows:
| Temperature (°C) | 23 | 692 | 767 |
| Modulus of elasticity (GPa) | - | 236 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 42 |
| Thermal conductivity (W/m·°C) | - | 23.3 | 41.2 |
| Specific thermal capacity (J/kg·°C) | - | 242 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.21 | - | - |
| Deity (kg/dm³) | - | - | 341 |
| Poisson’s coefficient, ν | - | - | 433 |
ASTM A312/A312M Type 304H Material Machining Technology
Machining of ASTM A312/A312M Type 304H steel is a highly complex process, but it is essential for producing items such as pipes and tubing. This special type of steel is an austenitic stainless steel, meaning it has a high level of corrosion and heat resistance due to its chromium content. Machining this type of steel requires precise control and a great deal of skill. As a result, it is only suitable for experienced machinists who understand the characteristics of this material and its machinability.