ASTM A312/A312M Type 309HCb Introduce
ASTM A312/A312M is the standard specification for seamless and welded austenitic stainless steel pipes for high temperature and general corrosive service. It covers austenitic stainless steel pipes used in corrosive and high temperature applications, including pipes for pressure vessels and heat exchangers.
Smelting temperature:1169°C - 1479°C
Application:Seamless and welded austenitic stainless steel tube
ASTM A312/A312M Type 309HCb Material Chemical Composition
The chemical composition of the ASTM A312/A312M Type 309HCb steel are as follows:
| Element | Min | Max |
|---|---|---|
| Silicon (Si) | - | 1.0000 |
| Sulfur (S) | - | 0.0300 |
| PhOsphorus (P) | - | 0.0450 |
| Nickel (Ni) | 12.0000 | 16.0000 |
| Niobium (Nb) | - | 1.1000 |
| Molybdenum (Mo) | - | 0.7500 |
| Manganese (Mn) | - | 2.0000 |
| Chromium (Cr) | 22.0000 | 24.0000 |
| Carbon (C) | 0.0400 | 0.1000 |
ASTM A312/A312M Type 309HCb Material Mechanical Properties
ASTM A312/A312M is a standard specification for seamless and welded austenitic stainless steel pipes used for high-temperature and general corrosive service. This specification covers nominal wall thickness, minimum wall thickness, and ASTM's requirements for chemical composition, mechanical properties, and burst testing of these stainless steel pipes. we will focus primarily on the mechanical properties of this stainless-steel pipe, as the most important factor for assessing the suitability of a pipe for a particular application will be determined by its mechanical properties.
The mechanical properties of the ASTM A312/A312M Type 309HCb steel are as follows:
| YieldRp0.2 | ≤ 261 (MPa) |
| TeileRm | ≤ 696 (MPa) |
| ImpactKV/Ku | 41(J) |
| ElongationA | 34% |
| Reduction in cross section on fractureZ | 24% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 441 |
ASTM A312/A312M Type 309HCb Material Thermal Properties
The thermal performance parameters of the ASTM A312/A312M Type 309HCb steel are as follows:
| Temperature (°C) | 44 | 529 | 655 |
| Modulus of elasticity (GPa) | - | 141 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 22 |
| Thermal conductivity (W/m·°C) | - | 34.3 | 13.2 |
| Specific thermal capacity (J/kg·°C) | - | 314 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.21 | - | - |
| Deity (kg/dm³) | - | - | 442 |
| Poisson’s coefficient, ν | - | - | 342 |
ASTM A312/A312M Type 309HCb Material Machining Technology
Machining of ASTM A312/A312M Type 309HCb 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.