After a weld is welded, the appearance quality can be observed and measured. However, the internal weld of the weld can be found by radiographic inspection, such as: porosity, inclusions, cracks, unfused and other defects.

The magnetization method uses a fixed electromagnetic yoke with two magnetic poles to clamp the parts for overall magnetization, or a portable electromagnetic yoke with two magnetic poles contacting the workpiece surface for local magnetization.

Non-destructive testing personnel shall perform X-ray shooting of the weld according to the number of films taken by the on-site surveyor and the position of the film.

Magnetization is divided into two directions: longitudinal magnetization, circumferential magnetization, and composite magnetization.

Magnetizing a workpiece that requires magnetization in a coil or magnetizing a large workpiece around a cable, often referred to as a coil method

NDT technology has a wide range of applications in the design, production, use and repair of ships. Special NDT technology is an important guarantee for the quality of shipbuilding.