ASTM B407 Incoloy 800H / UNS N08810 / 1.4958 Seamless Alloy Steel Tube

1. Solution Annealing:

   • The tube is heated to a temperature between 1900°F to 2100°F (1038°C to 1150°C).
   • This high-temperature treatment helps to dissolve any carbides and allows for the homogenization of the microstructure.

2. Holding Time:

   • The material is held at the solution annealing temperature for a specific duration, usually for about 30 minutes to 1 hour per inch of thickness, to ensure complete transformation and dissolution of phases.

3. Quenching:

   • After the holding time, the tube is rapidly cooled. This can be done using water quenching or oil quenching, depending on the specific manufacturing process and desired properties. Rapid cooling is essential to prevent the formation of adverse phases like sigma phase.

4. Stabilization (Optional):

   • In some cases, especially when service conditions involve exposure to higher temperatures, a stabilization anneal may be performed afterward. This involves heating the material at a lower temperature (around 1600°F to 1800°F or 871°C to 982°C) for a controlled time to enhance resistance to intergranular corrosion.

5. Final Cooling:

   • Following the quenching or stabilization, the tube is allowed to cool to room temperature. This ensures that the material remains in a favorable phase that provides the necessary strength and resistance characteristics.

Application

- Ethylene furnace quench boilers

- Hydrocarbon cracking

- Valves, fittings and other components exposed to corrosive attack from 1100-1800° F

- Industrial furnaces

- Heat-treating equipment

- Chemical and petrochemical processing

- Super-heater and re-heaters in power plants

- Pressure vessels

- Heat exchangers