NDT Testing

LIQUID PENETRANT INSPECTION according to ASTM E-1417

Liquid Penetrant Inspection (LPI) is a non-destructive testing method used to detect open surface defects on metallic and non-metallic materials. The method is described in ASTM E-1417, “Standard Practice for Liquid Penetrant Testing”.

In essence, the LPI test involves the application of a penetrating liquid, which can be colored or fluorescent, on the surface of the material to be tested. The liquid penetrates the open defects on the surface and is left to act for a certain period of time, usually 10-30 minutes, so that it can completely fill the defect.

Next, the penetrant is removed from the surface and a fixative is applied, which helps hold the penetrant within the defect. Finally, a developer is applied, which absorbs the remaining liquid penetrant and produces a visible reaction on the surface of the material, highlighting the defects.

The LPI test is used to detect surface defects such as cracks, porosity, pores, slag inclusions and other surface discontinuities that can affect material performance. The method is widely used in industries such as aerospace, automotive, electronics manufacturing, and the oil and gas industry.

MAGNETIC INSPECTION

Magnetic inspection, also known as magnetoscopy or magnetography, is a non-destructive testing method used to detect defects in the internal structure of ferromagnetic materials such as steel. The method is based on the use of magnetic fields to detect discontinuities in the material.

There are two main techniques for magnetic inspection: direct magnetization and indirect magnetization. In direct magnetization, a magnetic field is applied directly to the material to be tested, while in indirect magnetization, the magnetic field is generated by an electric current flowing through a coil placed close to the material.

Once the magnetic field has been applied, any changes in the magnetic field caused by any defects or discontinuities present in the material are observed. These changes can be visualized using special sensing techniques such as the use of magnetic particles or a magnetic field sensor.

Magnetic inspection is commonly used in various sectors such as aerospace, automotive, railway, petrochemical and in all cases where it is necessary to verify the structural integrity of metallic components.