In the overview of the Slitting Lines made by FIMI able to process high-strength steel, we would like to present the Case History of the last installed plant, that is the one made for Voestalpine Steel & Service Center and commissioned to FIMI for its own establishment of Linz in Austria.
Voestalpine is a world-leading steel and technological industry, composed of about 500 companies which constitute the Group operating at a global level in more than 50 countries.
The Customer need was to extend the already wide production range, adding a new plant for cutting high-strength steel coils into strips, characterized by an elevated technological level and an automation capable to control efficiency and performance.
Enquiries that our designers have been able to meet thanks to the know-how that FIMI can boast in almost 60 years of activity and more than 1.500 plants installed all over the world.
FIMI Slitting Lines for hot-rolled steels of thick gauge have been developed with success to be adapted to the typical application in structural engineering, cranes, lifting equipment in general, poles for wind turbines and the tube industry. Thickness standard range goes from 1 to 8 mm but, in some cases, it can be also 16-18 mm for tubes. These cutting lines require special solutions for the strip feeding process - in particular after the slitting shear - for the cutting, the handling of scrap, the recoiling and the discharge of slitted coils.
As mentioned before, the processing material is hot-rolled steel, pickled and not pickled, according to EN10025/ EN10149/EN10083/EN10084/EN10051 norms, dry and oiled, with tensile strength from 400 N/ mm2 to 1.500 N/ mm2 (up to 10 mm thickness), 1.300 N/mm2 (up to 12 mm thickness). Width from 300 up to 1.800 mm, thickness from 1,5 to 12 mm, maximum coil weight 40 Ton.
The plant layout is similar to the other Slitting Lines for thick gauge made with success by FIMI but with some peculiarities that mark it.
- The line has been equipped with a Notcher, a machine able to make two cuts on the strip edges about 1 meter from its head. This allows the strip to be introduced into the slitting shear reaching the final penetration value of blades before of these two cuts. This keeps the front of the strip in one piece and makes it easier to feed the material to the recoiling mandrel.
Moreover, the two cuts made by Notcher allow to remove the scrap from the head itself and to feed it into the scrap cutter.
- Then there are the automatic separators for thick gauge. This technology, employed in the thickness range up to 8 mm since many years, has been enlarged to all thickness range of this line allowing a setup time optimization and so an increase of productivity even on a line of these performances.
The slitting shear is equipped with an automatic centring device and a steering pinch roll. This last one guarantees to have always the material perfectly in the middle of the slitting shear blade formation, avoiding the risk to lose the scrap in case of material width irregularity.
The recoiling mandrel piloted with strip guide system for optimal wind alignment on the recoiled sub-coils, allowing also the usage of the line as recoiling with only rewound or trimmed strip.
The head and tail folding system which makes the head introduction and the strips discharge easier. This function is a must in the thick gauge lines where, in order to facilitate the discharge of the sub-coils and the circumferential strapping, the head and tail of the strips must be folded.
Furthermore, the line is also provided with an in-line electrostatic oiling machine.
Control systems as the thickness and width measuring device. The line, which is completely interfaced with the level 2, is able to compare the received information with the introduction of the coil and to verify the material quality, automatically rejecting what is not conform due to out-of-tolerance thickness. Moreover, downstream the slitting shear, the strips width is verified to track any tolerance defects.
Flanged mandrels with automatic changeover. The line can recoil the material of 3 different diameters: 508, 610 and 762. Each diameter can be processed by equipping the line with a special mandrel that is automatically replaced by a hydraulic locking system and with the usage of a change mandrels system by means of carriages. The changeover mandrel requires about 10 minutes and so it speeds up the equipment of the machine and the production change.
The configured plant achieves excellent performances, always guaranteeing quality and reliability, which are primary goals for all FIMI designed products.
For instance, it can made 20 cuts working at a speed of 200 m/min on thickness of 4 mm and 600 N/ mm2 of tensile strength or 10 cuts with 8 mm of thickness of 800 N/mm2.
Another important outcome concerns the scrap: the inlet is fully automatic and it is possible to cut and trim the material up to 100 mm of width.
As with all FIMI plants, the automation that equips the system plays a fundamental role in the quality of the project, not only in the performance and productivity sector but also for what concerns the efficiency of the line and the security for the operators who use it.
The automatic introduction of the material from uncoiler to recoiler and the automatic introduction of the scrap in channels are the most significant example. Once the head of the material is fed into the entry pinch roll, the process goes automatically on until the head of the material is ready to be introduced into the recoiling mandrel. This is useful since it enables to speed up a phase which is normally in charge of the operator and which may therefore be liable to interruptions or inefficiencies.
In almost sixty years of activity, FIMI has worked to be the answer to every need.
This is possible since FIMI has chosen a direction, planned its growth, invested on the technological research and on the staff formation, creating the perfect conditions to make always advanced solutions, tailored to specific needs of the individual customers.
Customers who rely on FIMI know that they will get what they want and what they need.