Metals industry

A piano is one of the most complex instruments to play, having 88 keys and countless combination possibilities. However, not only is playing the piano complex, but the mechanics behind it are too. Piano Wire, a spring wire drawn and turned into a spiral that is spun around the strings and vibrates as a result of hammer strokes, is especially important for sound generation. The sound generated in this way is amplified by the resonance chamber.

For an incomparable pure sound, high quality demands are placed on the material. The raw material is carefully selected and various control and testing mechanisms during the production of the spring wire ensure perfect quality. This is critical because, surface defects in the material, for example cracks, can negatively affect the sound or even cause the spring to break.

For perfect symphony to occur, the DEFECTOMAT and CIRCOGRAPH systems check the spring wire for longitudinally and transverse oriented surface defects. The complete process is carried out with non-destructive eddy current technology, with which even tiny material defects can be reliably detected. In this way, we invisibly contribute to a perfect sound.

For cutting or milling metals, extremely hard and wear-resistant tools are needed, so-called carbide tools. Hard metals have microstructures made of metallic hard materials such as tungsten carbide and a so-called binding metal, for example, cobalt.

To manufacture hard metal, the metallic hard material and the binder are mixed in powder form and finely ground. Next, the granulate is pressed in a mold and sintered. During this process, the binder is heated until it melts and fills in the hollow spaces between the carbides. This produces a blank that can be further processed into drill blanks or thread milling cutters for example.

Quality requirements of hard metals include the grain size as well as the homogenous structure of the sintered hard metals. The KOERZIMAT from FOERSTER provides information on the grain size and uniform distribution of the carbides in the sintered composite by determining the coercive field strength and the saturation magnetization. This ensures that the hard metals meet the high quality requirements.

What do a wind turbine, a container ship, and an oil rig have in common?

Thick and heavy plate is used for the construction or manufacturing of all three. The plate is manufactured in a steel mill. The raw material is large blocks of metal, so-called slabs. These are driven by giant pairs of rollers, the clearance of which is continually reduced. This is done until the desired plate thickness is achieved.

A distinction is made between the hot rolling and cold rolling process. In hot rolling, the material is processed while it is glowing hot. This process is used above all when the plate is to have a greater strength. Cold rolling is used for lower strengths. It is now standard to test the plates for quality and defects after rolling, since only tested material is used for shipbuilding or wind turbines.

The PLATEPROOF testing system from FOERSTER tests the plates for laminar discontinuities, using water-coupled ultrasonic methods. Automatic evaluation is then carried out from the acquired and processed data according to relevant testing standards. The largest testing width realized by FOERSTER to date is 5.4 m. Plates of this size are primarily used in shipbuilding and on oil rigs, or for the walls of chemical reactors and power plants.

The applications for heavy plate are as varied as the number of products made with the help of FOERSTER to ensure their quality.

During a train journey, have you ever wondered how the rails are made over which you smoothly travel?

While the early horse drawn rail systems were made of wood, the manufacture of railway tracks is now the task of highly specialized rail rolling mills. Reliability and safety are a major requirement of rails, and only high-quality steel is used for this, which is shaped in several rolling operations. Since the rails will be subject to great loads during service and have to last for many years, it is important that the rails are tested for material defects during manufacturing.

Due to the profile structure of the rails, special eddy current testing systems are necessary. For this reason, FOERSTER has developed the CIRCOSCAN sensor system. This is based on rotating discs that use the eddy current method to scan rails for longitudinally oriented surface defects in combination with the CIRCOGRAPH test electronics. The process works completely non-destructively and contactless. In this way, defects can be detected and corrected at an early stage. For the detection of transverse surface defects, the test electronics can be expanded to include the DEFECTOMAT. With this system, the rails are inspected with a special profile testing coil also using eddy current. The new ultrasonic system expands the FOERSTER product range with a method that can determine defects inside the rails. FOERSTER thus offers a complete solution for the quality control of rails.

Tested by us for you – to make train journeys relaxing.

Application Notes - Spring wire