Spiral steel pipe with double-sided submerged arc welding
Double-sided submerged arc welded spiral steel pipe has the advantages of high pressure capacity, low resistance, low temperature resistance, corrosion resistance, easy installation maintenance, etc., it is more more popular in oil gas, slurry transportation, urban construction other industries. Full board ultrasonic inspection.
Fatigue index of double-sided submerged arc welding spiral steel pipe
Fatigue: The metal material is below the ultimate strength is subjected to long-term alternating load (that is, the load with repeated changes in size direction). The phenomenon of sudden fracture without significant plastic deformation is called fatigue. Fatigue index includes fatigue limit fatigue strength.
Fatigue limit: The stress that a metal material can withstand under repeated alternating stresses without breaking after a weekly (N) stress cycle is called the fatigue limit
Fatigue strength: The stress that a metal material can withstand when it breaks after repeated cycles (N) under the action of repeated alternating stress is called fatigue strength. At this time, N is called the fatigue life of the material. Some metal materials have no obvious fatigue limit under the action of repeated alternating stress, are commonly expressed as fatigue strength.