LSAW steel pipe quality check methods, during which the physical approach is the most commonly used inspection methods, physical examination is the use of physical phenomena to determine or check the method.
Magnetic flaw detection can only find the appearance and appearance of magnetic straight seam welded pipe shortcomings, and the shortcomings can only do quantitative analysis, the nature and depth of the shortcomings can only be based on experience to estimate. Magnetic inspection is the use of magnetic field magnetization of ferromagnetic Longitudinal Welded Pipe leakage occurred to find the shortcomings. According to the measurement of magnetic flux leakage method is not the same, can be divided into magnetic powder method, magnetic induction method and magnetic recording method, during which the most widely used magnetic powder method.
Penetration test is the use of some of the liquid permeability and other physical properties to discover and show shortcomings, including the color check and fluorescence detection of two, can be used to view the appearance of ferromagnetic and non-ferromagnetic material shortcomings.
Radiographic testing is the use of ray penetrable material and attenuation in the material properties to detect defects in a method of detection. According to the different rays used in flaw detection, can be divided into X-ray detection, γ-ray detection, high-energy ray detection of three. Because of its shortcomings are not the same way, each ray detection are divided ionization method, fluorescent screen observation, photography and industrial television law. Ray inspection is mainly used to check the longitudinal seam weld internal cracks, not penetration, pores, slag and other shortcomings.
Ultrasonic flaw detection
Ultrasound in metal and other homogeneous media, because in the same media interface will occur on the reflection, and thus can be used for internal defects inspection. Ultrasonic can detect any weldment data, any part of the shortcomings, and can more sensitive to find the defect orientation, but the nature of the defect, shape and size of the more difficult to determine. So Longitudinal Welded Pipe Ultrasonic flaw detection and cooperation often used.