Boiler steam pipes require materials that can withstand high temperatures, pressure, and potential corrosion. Common materials include:

Carbon Steel: Grades like ASTM A106 (for seamless carbon steel pipes) are frequently used in high-temperature boiler steam lines, given their good mechanical properties and moderate cost. A106 Grade B is a popular choice in lower-pressure systems.

Alloy Steel: Alloys like ASTM A335 (e.g., P11, P22, and P91 grades) are used in higher-temperature and higher-pressure steam pipes. These alloys contain chromium and molybdenum, enhancing heat and corrosion resistance, making them ideal for superheaters and reheaters.

Stainless Steel: For extreme temperatures or environments with higher corrosion risks, stainless steel grades such as TP304, TP316, and TP347 are used. They offer excellent oxidation and creep resistance.

Ferritic and Martensitic Steels: These steels, containing chromium for corrosion resistance, are used in advanced applications due to their ability to maintain strength at elevated temperatures, though they are more costly than carbon steel.

Each material is selected based on the specific conditions within the boiler system, balancing factors such as cost, corrosion resistance, and mechanical strength.