Straight seam steel pipe breakage

Generally, hydraulic ( pneumatic ) parts in the design using the mechanical properties are assumed material is uniform, continuous, isotropic, According to this method of design that is safe, sometimes accidents fracture accidents.

Straight seam steel pipe(lsaw steel pipe) drawing, since the hot tube defects such as cracks or high-precision drawing after the tank is made, in the course of the fracture occurred, almost no plastic deformation occurs, in general are brittle fracture. Brittle fracture is caused by a variety of reasons. Such as: precipitates on the grain boundaries, regardless of the intensity ratio of the matrix strength strong or weak, are all causes cracks; grain boundary segregation of inclusions also cause fracture; addition, even in far less than the yield limit of the cross- variable loads, can also cause fatigue fracture phenomena.

Found brittle fracture but also with use of components temperature. The study found that people when the temperature drops below a certain temperature, the material will be brittle transition state, the impact absorbed energy decreased, a phenomenon known as cold brittleness, high strength metal materials, low stress occurring in brittle fracture process, the material structure is far from homogeneous and isotropic. Tissues have cracks, there will be inclusions, porosity and other defects, which are a material can be seen in the micro- cracks. Therefore, the design also according to the operating temperature to select members with appropriate cold brittle transition temperature of the material.