(1) Importance of structure Heavy industrial building structures, large-span structures, high-rise or super high-rise civil building structures or structures, etc., should consider the selection of good quality seamless steel pipes. For general industrial and civil building structures, press The nature of the work is selected from ordinary quality seamless steel pipes.
(2) Load conditions For structures directly subjected to dynamic loads and structures of strong seismic zones, seamless steel pipes with good comprehensive performance should be selected; for structures with static load, low-cost seamless steel pipes can be used.
(3) Connection method Welding deformation, welding stress and other welding defects may occur during the welding process, and there is a risk of causing cracks or brittle fractures in the structure. Therefore, the material requirements of the welded structure should be stricter.
(4) The temperature and environment in which the structure is located. When the seamless steel pipe is at low temperature, it is easy to be cold and brittle. Therefore, the structure working under low temperature conditions, especially the welded structure, should be made of killed steel with good resistance to low temperature brittle fracture. In addition, the Taiyuan seamless steel pipe with open-air structure is prone to aging, and the seamless steel pipe with harmful medium is easy to corrode, fatigue and break, and different materials should be selected differently.
(5) The thickness of the too seamless steel tube, the number of times of thin seamless steel pipe rolling, the compression ratio of rolling is large, and the compression ratio of seamless steel pipe with large thickness is small, so the precision steel pipe with large thickness is not only low in strength, but also plastic and impact. Toughness and weldability are also poor. Therefore, the welded structure with a large thickness should be made of a seamless steel pipe with a better material.