Teräs

In steel plants, equipment that processes sinter at very high temperature is exposed to severe wear conditions. In particular, the sinter crusher that has to ensure large through-put must be wear-protected in order to avoid expensive maintenance and frequent plant shutdowns. Maintenance Managers agree that standard solutions available on the market are not sufficient for their needs. Rotors and breaker bars must regularly be replaced with new ones.
The insufficient wear resistance of the standard solutions is due to three main factors:

•    the sinter high temperature that reduces the hardfacing characteristics,
•    the sinter abrasive nature that wears-out the parts,
•    the high impacts that destroy brittle hardfacings.

e3 is a legally protected solution specifically developed for improving steel sinter crusher productivity and service life. This solution is born after 4 years of tests made in laboratory as well as on real working conditions. It is based on a unique Castolin Eutectic high temperature wear-resistant alloy that offers extreme resistance even when impact and abrasion are present. e3 is particularly suitable for protecting the critical sinter crusher parts such as the rotor discs, teeth and breaker bars. On-site tests have shown that e3 outperforms standard solutions by at least a factor 3. In addition to increasing service life, the geometrical shape of the parts is preserved, which ensures better crusher efficiency compared to standard solutions.

In addition to boosting part service life, e3 allows you:

•    to reduce frequent sinter crusher maintenance and plant shutdowns,
•    to get higher crusher productivity by preserving teeth shape,
•    to reduce purchasing costs of new parts,
•    to avoid using complex water-cooled breaker bars.

We offer a comprehensive range of wear-resistant sieves with round, square or oval apertures manufactured from 3 mm thick or higher, perforated sheets. We also manufacture tailor-made solutions according to specific customer requests. Our production technology uses a state-of-the-art, high power laser cladding installation. This system ensures highest quality wearfacing coatings of tungsten carbides dispersed in a nickel-based matrix to protect standard perforated steel sheets with variable mesh sizes.

The ultra hard tungsten carbide phases which are homogeneously distributed within a self-fluxing, tough nickel-based alloy matrix, provide:

• Extreme wear resistance performance against abrasion and erosion up to 10 times higher than standard, monolithic heat-treated steel alternatives.
• Withstands operating service temperatures up to 400°C. For even higher service temperature requirements, a diverse range of special alloy systems may be proposed to meet specific customer needs.

Modern Castolin Eutectic LaserClad technology uses a focused laser beam to ensure low heat input welding conditions, which translates into extremely effective, wear protective coatings on industrial parts.

After mixing the raw materials in the sinter plants (fine iron ores, additives such as limestone and olivine, recycled iron-bearing materials  from downstream operations, and coke breeze) we find a roller just underneath the charging system to constantly feed the sinter belt which is affected by abrasion. The lifetime of this feeding roller can be increased by our turnkey solutions.

In most cases after the sinter discharge, crushing and hot screening, the sintered material proceeds to a separate cooler. This is typically a rotating structure, divided into circular sectors with tipping devices, in which the sinter is placed in a layer more than 1 m thick and cooled by fresh air.

When the sinter has completed the cooling cycle, each sector is emptied via the tipping device. The cooled sinter is transferred to screens that separate the pieces to be used in the blast furnace.

Both the charge and discharge of the cooler deteriorate the surfaces whose lifetime can be increased with our CDP® wearplates.

Along the whole sinter process, several metallurgical and chemical reactions take place which produce dust and gaseous emissions apart from the sinter itself. These gases contain particles such as heavy metals that will weaken the inner surface of air suction systems.

A complete high resistance conduction system including valves and transitions circular to square section can be manufactured with our CDP® wearplates.

Extensive in-process damage to the external diameter of the Tuyere Cooler component, used in Blast Furnace operations, is a common occurrence and can lead to reduced processing capability and equipment downtime. This is especially pertinent when the substrate damage results in the Tuyere becoming lodged in the parent housing and having to be forcibly removed. Tata Steel together with Castolin Eutectic have developed a thermal spray deposition which would help negate the potential damage to the component and thus extend its useful processing life by reducing the build up and adhesion of Blast furnace by-products.

After extensive trials a composite coating structure comprising of a High Velocity Oxy Fuel (HVOF) deposited Nickel-Chromium coating together with a thermally converted slurry addition was used to protect the affected external surface. This coating produces a pore-free surface which inhibits the adhesion of the process by-products whilst protecting the substrate from extensive wear by chemical erosion.

The CastCoat hard composite coating was developed by the advanced Castolin Eutectic workshop in Newcastle, UK, for steel industry applications in particular for coating continuous Caster copper mould plates, for more than 20 years. Tests have shown that the coating is tougher than any other copper mould plate coating available. It has a low coefficient of friction which helps reduce sticker alarms and the coating is inert to liquid steel and casting powders. The coating system has no effect on mould level detectors or electromagnetic stirrers. It has also been proven that the coating has negligible effect on heat transfer rates.

With years of field data behind the coating, significant copper plate life improvements have been demonstrated: 3 – 4 times for thick slab casters and up to 6 times for thin slab caster narrow plates, accompanied by improved product shape. In operation, the coating has been shown to enable extended casting runs through dramatic increases in wear resistance. Eventual progressive degradation of the coating occurs due to the thermal fatigue in high stress positions. Now a mature technology with a worldwide customer base, CastCoat continues to provide users with reduced costs/tonne.

By coating all four faces of the mould, dimensional stability is retained throughout the campaign, leading to sustained and effective product shape and shell growth. The lack of appreciable wear means longer campaigns are possible between mould exchanges, achieving higher caster availability. In addition, the protection offered by the coating gives extended copper plate life, resulting in annual copper savings and delivering significant reductions in both on and off-line maintenance costs. With the recent development of a compact HVOF device, the CastCoat Composite Coating can now be applied to tube moulds.