According to statistics of seamless steel pipe technical data, 80% of steel pipe fractures are caused by fatigue. The main points are analyzed as follows:

Steel pipe fatigue: The size and direction of the load bearing periodically change with time. Under the action of alternating stress, it often breaks under a stress far less than the strength limit, or even less than the yield limit.

Fatigue limit of steel pipe: The highest stress value at which a material can undergo numerous stress cycles without fatigue fracture.

Steel pipe condition fatigue limit: the maximum stress value that can withstand 107 stress cycles without breaking.

Factors affecting steel pipe fatigue

Cyclic stress characteristics, temperature, material composition and organization, inclusions, surface state, residual stress, etc.

Other factors related to fatigue

The fatigue resistance of ceramics and polymer materials is very low, the fatigue strength of metal materials is high, and fiber-reinforced composite materials also have good fatigue resistance.