1. Generally speaking: Due to the strong bending resistance of steel pipes, in recent years, they have been widely used in the roof frames, beams, and columns of buildings such as factory halls and stadiums. For example, the construction of Beijing's sports venues, Chengdu, Shanghai, Shenyang airports, and other terminal buildings. Seamless steel pipes of various grades produced in accordance with domestic and international standards, including carbon structural steel, low-alloy structural steel, alloy structural steel, and stainless steel, are playing an increasingly significant role in the national economic development and the improvement of people's living standards.

2. High-pressure Seamless Steel Tubes for Thermal Power Boilers: · Diagram of power plant boiler: The process of heating water into steam and superheating the steam: Softened water enters the boiler first into the economizer, where it is heated by the residual heat of the flame within the furnace to increase the water temperature. It then enters the water-cooled wall tubes arranged around the furnace, where it is heated by the flame burning within the furnace, transforming into wet steam. This steam is collected in the drum for water and steam separation. The separated water re-enters the water-cooled wall, while the steam enters the superheater located above the furnace, further heating it to reach the required temperature and pressure. The steam is then sent through steam pipes outside the boiler to the steam turbine. After passing through the turbine, the steam's temperature and pressure have significantly decreased and must be returned to the boiler. It is reheated in the reheater to become superheated steam for reuse. The technical specifications of high-pressure boiler tubes also continuously improve with the development of power plant units. Initially, the capacity was nearly 10,000 kW, which later increased to 100,000, 200,000, 300,000, and 600,000 kW. Currently, the single unit capacity of the new power plant in Pudong has reached 900,000 kW. This requires the steel tubes within the boiler to withstand higher temperatures and pressures. For example, the steam pressure has gradually increased from the early 4 MPa to the current 25-30 MPa, and the steam temperature has risen from 450°C to 540-560°C. The high wall temperatures of the superheater and reheater tubes have reached 600-630°C. To meet these development requirements, the steel material for high-pressure boiler tubes has evolved from carbon steel to low-alloy steels, alloy steels, and high-alloy heat-resistant steels, with a higher purity requirement for the steel.

3. Drilling Oil and Gas Wells: Oil and natural gas are deeply buried underground. To extract them, drilling wells (oil wells or gas wells) must be done by boring down from the ground surface. The drilling process involves the use of drilling tools, where the drill string, consisting of steel pipes connected together (excluding the drill bit), is the core tool used to bore holes from the ground to the bottom of the well. It also serves as a conduit from the ground to the wellbore. The drill string is composed of a square drill pipe, drill pipes (including a few heavy-weight drill pipes), and drill collars, with the majority being the drill pipes. During drilling, the drilling rig rotates the square drill pipe, which is connected to the bottom of the drill pipe. The drill pipe is then connected to the drill collar and drill bit below. The drill pipe thus plays a role in transmitting power and transporting drilling mud. As the drilling depth increases, the drill pipes are added one by one and connected to continuously lengthen the drill string until the required depth is reached. During the drilling process, casing must be inserted based on the stratigraphic conditions to support the wellbore of the oil or gas well. Depending on the depth and stratigraphy, multiple layers of casing are typically required for a single well, including surface casing, technical casing, and oil (or gas) casing.