The material of large - diameter steel pipes mainly depends on specific application scenarios and requirements, such as conditions of withstanding pressure, temperature, and corrosion. The following are some common materials for large - diameter steel pipes:

Carbon steel: It is mainly used for general transmission pipelines and has fairly good pressure - bearing capacity and corrosion - resistance performance.

Stainless steel: It is suitable for highly corrosive and high - temperature environments, such as in the fields of chemical industry and seawater desalination.

Alloy steel: It is suitable for high - temperature and high - pressure environments, such as in the fields of petroleum and chemical industry.

Copper alloy: It is suitable for transporting high - purity gases and liquids, such as in the fields of aerospace and electronics.

Aluminum alloy: It is lightweight and suitable for transporting low - pressure gases and liquids, such as in the fields of ventilation and refrigeration.

The above are some common materials, and the specific selection still needs to be determined according to actual needs and design requirements.