Fatigue index of double-sided submerged arc ssaw steel pipe:
1) Fatigue: Under the ultimate strength, the metal material is under alternating load (ie size, direction and load change) for a long time. In this case, there will be no obvious plastic deformation and sudden fracture, which is called fatigue. The fatigue index includes fatigue limit and fatigue strength.
2) Fatigue limit: How much stress a metal material can withstand under repeated or alternating stress cycles is called the fatigue limit.
3) Fatigue strength: The larger stress that a metal material bears under repeated or alternating stress is called fatigue strength. At this point, N is referred to as the fatigue life of the material. Some metal materials have no obvious fatigue limit under repeated or alternating stress, and fatigue strength is commonly used.
After the steel plate enters the production line, ultrasonic flaw detection of the whole plate is firstly carried out. In addition, according to API standards and other relevant standards and the special requirements of some users, it is also necessary to carry out damage detection on ssaw steel pipes, including the physical and chemical properties of raw materials, and the inspection of the appearance of steel plates.
Tips: ssaw steel pipes are mainly used in tap water engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, urban construction, and are one of the 20 key products developed in my country. For liquid transportation: water supply, drainage, sewage treatment engineering, mud transportation, marine water transportation; for gas transportation: gas, steam, liquefied petroleum gas; for structure: as piling pipe, as bridge, wharf, road, building structure with pipes, marine piling pipes, etc.