ASTM A376 TP347H Stainless Steel Seamless Pipe for High Temperature

ASTM A376 TP347H Stainless Steel Seamless Pipe for High-Temperature

ASTM A376 is a standard developed by the American Society for Testing and Materials for austenitic stainless steel seamless pipes used in high-temperature central stations. It emphasizes the long-term performance of steel pipes in high-temperature operating environments and specifies requirements for chemical composition, mechanical properties, dimensional tolerances, heat treatment processes, and testing methods. TP347H is a grade under this standard. With a high carbon content, it exhibits high creep and endurance strength at high temperatures. It is primarily suitable for designs in high-temperature and high-pressure environments, such as power plant boilers, superheaters, and reheaters.

ASTM A376 Stainless Steel Seamless Pipe Chemical Composition

ASTM A376 TP347H Stainless Steel Seamless Pipe Mechanical Properties

Comparison of ASTM A376 TP347H with Other Materials

• vs. TP304H: TP304H is the most widely used high-temperature austenitic stainless steel, but it contains no stabilizing elements. Therefore, it presents a risk of intergranular corrosion when welded or used in sensitive temperature ranges. TP347H addresses this issue by adding niobium, resulting in improved weldability.
• vs. TP321H: TP321H is a titanium-stabilized austenitic stainless steel, also designed to address intergranular corrosion. However, titanium easily forms inclusions such as titanium nitride at high temperatures, which can affect high-temperature strength. Niobium-stabilized TP347H, on the other hand, offers superior high-temperature strength.
• vs. TP347: Standard TP347 has a lower upper limit on carbon content, generally ≤0.08%. Its high-temperature strength is inferior to TP347H, making it unsuitable for the highest-performance ultra-supercritical units.

ASTM A376 TP347H Stainless Steel Seamless Pipe Application

1.Power Generation Industry (Core Application): Superheaters and reheaters for supercritical and ultra-supercritical power plant boilers, main steam piping, high-temperature reheat piping, and other heat exchange tube bundles subject to high temperatures and high pressures.

2.Petrochemical Industry: Ethylene cracking furnace tubes, hydrogen conversion furnace tubes, and other process piping for high-temperature environments.

3.Nuclear Industry: Certain non-nuclear-grade auxiliary piping systems within nuclear power plants that require high-temperature performance.