There are many kinds of custom-made quality inspection methods for stainless steel welded pipes. Among them, physical methods are also commonly used inspection methods. Physical inspection is a method of measuring or inspecting using some physical phenomena. The inspection of materials or internal defects of stainless steel welded pipes generally adopts non-destructive testing methods. The current non-destructive testing includes magnetic testing, ultrasonic testing, radiographic testing, penetrating testing, etc.

Magnetic inspection 　　

Magnetic inspection can only find defects on the surface and near the surface of customized magnetic stainless steel welded pipes, and only quantitative analysis of defects can be done, and the nature and depth of defects can only be estimated based on experience. Magnetic inspection is to use magnetic field magnetization of ferromagnetic stainless steel welded pipes to generate magnetic flux leakage to find defects. According to the different methods of measuring magnetic flux leakage, it can be divided into magnetic particle method, magnetic induction method and magnetic recording method. Among them, the magnetic particle method is widely used.

Penetration test 　　

Penetration inspection uses physical properties such as the permeability of certain liquids to find and display defects, including coloring inspection and fluorescent inspection, which can be used to inspect defects on the surface of ferromagnetic and non-ferromagnetic materials.

Radiographic inspection 　

Radiation inspection is a method of detecting defects by using radiopaque materials and the characteristics of attenuation in the materials. According to the different rays used in flaw detection, it can be divided into three types: X-ray flaw detection, γ-ray flaw detection, and high-energy ray flaw detection. Because of the different methods of displaying defects, each type of radiographic inspection is divided into ionization method, fluorescent screen observation method, photographic method and industrial television method. Radiographic inspection is mainly used to inspect defects such as cracks, incomplete penetration, pores, and slag inclusions in the weld of stainless steel welded pipes.

Ultrasonic flaw detection

When ultrasonic waves propagate in metals and other homogeneous media, they can be used for internal defect inspection because they reflect on the interface of different media. Ultrasonic can detect defects in any weldment material and any part, and can find the defect location more sensitively, but it is difficult to determine the nature, shape and size of the defect. Therefore, ultrasonic inspection of stainless steel welded pipe is often used in conjunction with radiographic inspection.