Non-destructive Testing of Parts

The STF Testing Center offers non-destructive material tests such as ultrasonic (UT) and radiographic tests (RT) not only stationary at the laboratory at Oberteuringen but also with the mobile lab van at your premises. The mobile lab provides the test results immediately and enables you to react at once.

Defects in welds, cast parts or other raw materials can be detected with these processes. Besides radiographic and ultrasonic tests we also offer dye penetrant testing (PT), magnet particle testing (MT) as well as visual tests (VT).

All these procedures are executed with state-of-the-art technique by personnel qualified according to DIN EN ISO 9712.

Ultrasonic Testing

Through acoustic pulses, ultrasonic testing reveals defects, such as cracks, porosities and lacks of fusion.
Additionally, sheet metals can be checked for doublings i.e. rolling defects.

Ultrasonic testing (UT) sends soundwaves into the part to be tested by a probe.

According to this principle, welds are tested for cracks, porosities and lack of fusion. Additionally, sheet metal thicknesses and residual wall thickness of pipes and vessels can be determined.

In ultrasonic testing of sheet metals for doublings (rolling defects), the probe sends soundwaves into the sheet metal to fully traverse it and to return thereafter to the probe.

The thickness of the sheet metal, i.e. the distance, is determined by the ratio sonic speed to sonic transit time. If the sheet metal has a concentric rolling defect i.e. a doubling, the echo shows a peak on the device’s display.

We perform this test both, in our facilities and in your workshop or at your construction site.

Radiographic Testing

The radiographic or x-ray testing uncovers internal defects, such as cracks or porosities, in welds.

For radiographic or X-ray testing ionizing radiation is generated with an X-ray tube. It penetrates materials such as steel and densifies a silver bromide coated film attached to the component.

Porosities or blowholes in the test component are shown as dark areas on the x-ray film. At defects, the ionizing radiation penetrates less material and therefore more radiation impinges on the film.

Components or objects, accessible from at least two sides, can be tested with  radiographic or X-ray inspection.

Radiographic technology is often used to test weldsand cast parts. Furthermore, plug-in connections can be tested for junction without destruction.

We perform this test both, in our facilities and in your workshop or at your construction site.

Penetrant Test

The penetrant test (PT) quickly and uncomplicated reveals defects opening to the surface, such as porosities and cracks.

For the dye penetrant test the component is cleaned to prevent later misinterpretations due to grease or dirt on the surface.

A colored, almost red, dye penetrant is sprayed on. Due to the capillary effect, it penetrates existing cracks or porosities.

After the stipulated penetration time, the penetrant is superficially washed off.

The component is dried and a developer is sprayed onto the spot to be tested.

After the given developing time, upwardly open cracks or porosities are visible on the component and will be evaluated by our level-2-certified testers.

We perform this test both, in our facilities and your workshop or at your construction site.

Magnetic Particle Test

Magnetic particle test is applied to ferromagnetic materials to find defects, such as porosities or cracks, on or near the surface.

Magnetic particle testing (MT) can be applied to all ferromagnetic materials.

For magnetic particle testing a magnetic field is induced to the component between two poles by a hand yoke. The testing surface is sprayed with a suspension enriched with magnetic chips.

If the tested area does not have material separations such as cracks, porosities or harsh transitions, the magnetic field  "flows" through the part without interruption.

If there is a material separation within the component, permeability of the component and of the defect differ so much that the magnetic field "diverts"and emerges to the surface. The previously applied enriched suspension forms a visible "powder caterpillar" providing for the evaluation by the inspector.

We perform this test both, in our facilities and your workshop or at your construction site.

Visual Test

Through direct and indirect visual testing (VT), components are checked for mechanical defects or surface qualities are evaluated. Welds are evaluated according to the regulations by using visual criteria.

During the direct visual test (VT = visual test), the tested part is inspected without tools. Criteria like surface quality of cast parts are evaluated or serial parts are checked for mechanical damage.

For theindirect visual test viewing devices such as an endoscope or a mirror are used. With the endoscope the inside of a component or of a pipeline is examined. Hard-to-access areas are examined with mirrors. This is not possible without optical devices.

Welds are visually tested for specified values such as excess weld metals, undercuts or design throat thickness.

Our team helps When final inspection by your own staff is insufficient, as the customer or the respective regulations require certified personnel,

We perform the tests in our testing center, at your factory or on  site.

Materialanalysis / X-ray Fluorescence Analysis RFA

The x-ray fluorescence analysis determines the material composition of the present raw material or work piece.

The STF RFA equipment facilitates the analysis of metallic materials such as steel, stainless steel, titanium and aluminum as well as their alloys. Their contents are recorded in percent and can be printed out.