Straight seam welded pipe quality inspection method,

There are many kinds of straight seam welded pipe quality inspection method, physical method which is the most commonly used inspection method, physical test some physical phenomena is used for measurement or test methods. Material or internal defects of Q235B straight seam welded pipe inspection, are generally adopt the method of nondestructive flaw detection. Current NDT magnetic testing, ultrasonic testing, X-ray flaw detection, penetration testing, etc.

 Magnetic inspection

 Magnetic testing can only be found magnetic Q235B straight seam welded pipe surface and near surface defects, and can only do quantitative analysis of defects, for the nature of the defect and depth also can only be estimated according to the experience. Magnetic inspection is ferromagnetic magnetization of the magnetic fields produced by Q235B straight seam welded pipe leakage to find defects. According to the different method of measurement of magnetic flux leakage, the magnetic particles can be divided into method, induction method and magnetic recording, of which the most widely used method of magnetic powder.

Penetrant inspection

Some liquid penetrant inspection is to use the physical properties such as permeability to find and display defects, including two fluorescent dye penetrant inspection and testing, can be used to check the ferromagnetic and the defects on the surface of the ferromagnetic materials.

X-ray detector

Radiographic examination is to use the rays can penetrate and attenuation in the material properties to find a flaw detection method. According to the detection of radiation is different, can be divided into X ray flaw detection and gamma ray flaw detection and high-energy X-ray detector. Due to the different methods display the defect, each ray flaw detection and ionization method, screen method of observation, photography and industrial television method. Ray inspection is mainly used for Q235B straight seam welded pipe inside weld crack, lack of penetration, porosity, slag inclusion and other defects.

Ultrasonic flaw detection

Ultrasound in metal and other homogeneous medium propagation, due to the different medium interface will produce reflection, thus can be used in the inspection of internal defects. Ultrasound can test any welding materials, any part of the defects, and is more sensitive to find defect position, but the nature of defects, shape and size are difficult to determine. So Q235B straight seam welded pipe ultrasonic testing is often used with X-ray inspection