Nondestructive testing (NDT)
We develop and implement processes for the nondestructive testing (NDT) of tubular and flat products as well as new process control methods and also provide ad-hoc assistance.
In our NDT laboratory we have a wide range of equipment at our disposal:
- Ultrasonic (UT) diving technology (scanner, pipe testing)
- High-frequency ultrasound for the detection of purity levels (MIDAS)
- Test bench for magnetic particle testing (MT)
- Roller tables and scanners for electromagnetic processes: Eddy current (ET), flux leakage (FT)
- Equipment for dye penetrant testing (PT)
- X-ray equipment (RT)
For mobile use:
- UT (also phased array) with mobile scanners
All tests are performed by certified employees (according to ISO 9712 Level 2 and 3).
Equipment for the ultrasonic inspection of welded pipes, plates/sheets and containers
The design and manufacture of ultrasonic inspection systems for use in production operations require comprehensive knowledge of the industrial ultrasound application. We have many years of experience in the fabrication of customer-specific solutions. Along with comprehensive know-how in testing technology, we offer impressive inspection and assessment concepts with solid execution as well as clear and simple system operation.
Testing technology, testing electronics, testing mechanics, equipment control system and the integration of operating data acquisition (ODA) form a complete, optimally matched system.
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We design and manufacture customized sensors, especially for the processes eddy current (coils), flux leakage (Hall and GMR sensors) and EMAT (coil systems with integrated magnets), e. g:
- water-cooled coils for hot tube testing
- EMAT systems for the excitation of rotating waves
We have been using the finite element method (FEM) in 2D and 3D for years now – to better understand and optimize inspection methods and their analysis, for example.
We work with the COMSOL Multiphysics program, which we can be used to link different physical scenarios together. We also conduct simulations in the main areas of electromagnetic systems and acoustics. For the design of ultrasonic inspection and eddy current testing, we rely on the commercial software package CIVA.
Used to improve defect characterization
The increasing availability of hand-held devices with special software modules has broadened the use of ultrasonic imaging in recent years. We use this technology in the form of hardware and software that we develop on our own as well as commercially available products. They include:
- Synthetic Aperture Focusing Technique (SAFT)
- Total Focusing Method (TFM)
- Time of Flight Diffraction (ToFD)
We apply ultrasonic imaging mainly to achieve better defect characterization than with conventional methods of defect analysis.
Marking and sorting pipes
In a magnetically saturated pipe, external and internal defects disturb the magnetic field lines creating a so-called “flux leakage”. The flux leakage emitted on the surface can be recorded with magnetically sensitive sensors and used to detect inhomogeneity. The signals are further processed (filtered, classified, etc.) and used to mark and sort pipes.
For the first time worldwide, we developed and implemented an operational testing unit that uses giant magnetoresistance (GMR) sensors to record flux leakage.
Testing of steel pipes with larger outside diameter
The testing of pipes for discontinuities or material mix-ups can be automated at high testing speeds. This test method is often combined in multi-test blocks with other methods – generally ultrasonic inspection. We support production operations in the areas of equipment verification, probe design, probe fabrication, filter techniques (e.g. wavelet) and evaluation procedures.
... at temperatures up to 600 °C – developed by SZMF
Electromagnetic acoustic transducers (EMATs) can be used to conduct couplant-free ultrasonic wall thickness measurements on electrically conductive materials even at high temperatures. Unlike the conventional method, ultrasonic (US) waves are excited inside the specimen via electromagnetic interaction, thereby eliminating the need for a couplant to transmit sound. In ferromagnetic steels, especially effective transversal US waves are excited.
With special transmission and receiving electronics, EMATs can be operated with nearly all standard ultrasound testing and evaluation systems.
Direct transferability of results to the material steel
Our ultrasonic visualization system is based on the photoelastic effect. This enables the system to render transversal and longitudinal waves visible in the material glass. Various types of glass are used, in which the sound velocities are very similar to those in steel. That is the basic precondition for the direct transferability of the results. Using the available evaluation software, the system measures the photoelastic images quantitatively (as a function of location and time). This makes it possible to reach reliable conclusions about the actual angle of incidence, acoustic beam divergence, focus points, etc. of real transducers.
Suitable for a wide range of applications!
Applications range from simple thickness measurement on a substrate (e.g. paint) to the highly demanding longitudinally scaled depth profiling of thermal and/or optical properties. Practical examples of the method include the characterization of anticorrosion primers on automotive metal sheets with regard to their weldability, determination of the thickness of scale layers on piercing mandrels, and the depth profiling of hardness values.
Active thermography requires thermal or mechanical excitation, at which induction coils, strobe lamps or high-intensity focused ultrasound are often used. Application areas include moisture detection, delamination, and inspection for cracks, inhomogeneities or other inclusions.
Passive thermography observes e. g. cooling conditioned by the process.
Our patented process identifies pipes made from the wrong material
In the production of steel pipes, material/batch mix-ups must be avoided. To make sure this doesn't happen, manufacturers sometimes use electromagnetic processes. Materials can be distinguished from each other based on their different magnetic characteristics. In this context, measurement data often lie very close together (specifically in the case of identically alloyed steels with different heat treatment). An expanded analysis with greater sensitivity and selectivity based on different data mining algorithms was developed and patented.
Rapid geometric acquisition of large objects and areas
3D laser scanners are used to measure buildings and plants.
The beam of a laser-based distance measurement system is refracted into two orthogonal angles and uses high measurement frequency to determine the distance to all object points in the scanning area. We then use that measurement data to prepare CAD models.
Standard-compliant inspection and analysis
As X-ray sources, we use our 200-kV micro-focus X-ray unit and a 320-kV direct emitter. This makes it possible to conduct weld inspections according to DIN EN ISO 17636-2 Class B. A highly effective software program, partly developed in-house, enables certified inspectors (EN 9712 Level 2 and 3) to conduct standard-compliant inspection and analysis.
Non-contact, material-independent determination of 3D surface coordinates
For specimens under both static and dynamic loads. Large displacements and deformations (>> 100%) can be measured in specimens ranging in size from a few millimeters to several meters.
We use two ARAMIS systems that use the principle of digital image correlation. They give us precise information about 3D displacement and velocities while also providing data about strains and strain rates across an angular range of nearly 180° at the same time.