There are many longitudinal quality inspection method, wherein the physical method is the most commonly used test methods, physical examination is the use of some physical phenomena or measurement methods were tested. Longitudinal Q235B material or internal defects and inspection, it is generally used NDT methods. The current non-destructive testing with a magnetic detection, ultrasonic flaw detection, radiation detection, penetration testing and so on.
Magnetic inspection
Magnetic testing can only find defects Longitudinal magnetic surface and near surface defects and can only do quantitative analysis, the nature and depth of the defect can only be estimated based on experience. Test is the use of magnetic leakage magnetic field generated by the magnetization of ferromagnetic Longitudinal to discover defects. Press the measurement of magnetic flux leakage methods can be divided into magnetic particle method, the magnetic induction method and a magnetic recording method, in which the magnetic particle method most widely used.
Penetrant inspection
Penetration testing is the use of permeability and other physical properties of certain liquids to discover and display defects, including coloring test testing two kinds of fluorescence can be used to detect defects of ferromagnetic and non-ferromagnetic material surface.
Ray detection
Ray detection is the use of substances and attenuation in the material properties rays penetrate to discover a flaw detection method for defects. Press ray detection used can be divided into X-ray detection, γ-ray detection, energy-ray detection of three. Because of their different methods of displaying defect, each ray detection are divided ionization method, screen observation, photographically and industrial Television Act. Ray inspection is mainly used to test the internal Longitudinal welds crack, incomplete penetration, porosity, slag and other defects.
Ultrasonic Inspection
Ultrasonic metal and other media spread evenly, since the interface of different media will produce reflection, it can be used to test internal defects. Ultrasonic welding can test any piece of material, defects in any part of, and can be more sensitive to the position of a defect is discovered, but the nature of the defect, the shape and size difficult to determine.
