GLOBAL CEMENT: WEAR PROTECTION

Castolin Eutectic

Castolin Eutectic unveils HD8 Coating

HD8 is an extremely wear-resistant coating made with an innovative, high-deposition welding

technique. It delivers a very high density of tungsten carbides that are homogeneously distributed within a nickel-based matrix at high deposition rates. The critical parameters of the HD8 process, particularly the temperature, are automatically controlled in order to avoid severe carbide dissolution, which may occur in standard welding techniques. The coating is optimised with a low dilution, so the overlay chem-istry is not negatively affected by the base material. Its wear resistance is far superior to steel hardened plates or chromium carbide wearplates according to ASTM G65.

Its extreme wear-resistance, coupled to its smooth and regular surface, means that HD8 is appropriate for situations where standard chromium carbide wearplates are too heavy and/or not resistant enough, particularly where high production throughputs are required.

HD8 is typically employed in: Low angle, high speed erosion conditions in the presence of fine particles; For abrasion conditions in which a high

production throughput is required; When maintenance is difficult to perform and; Where a maximum equip-ment lifetime is requested. HD8 increases machine service life and consequently reduces the costs associated with purchasing new parts and the time lost when these are replaced, vital in processes like cement manufacturing.

In order to provide the optimum wear-protection and avoid unnecessary costs, the Castolin Eutectic automated changeover system allows continuous beads of different alloys to be produced on the same surface. This ensures a smooth and regular surface. Consequently, the area exposed to the toughest wear can be coated with HD8, while an iron-based powder can be deposited where wear is less severe. This opti-mises the part service life and is cost-effective.

More HD8 Coating applicationsIn the cement industry, cross-bar coolers for clinker suffer from aggressive wear. Reciprocating cross bars fitted above the stationary air distribution system convey the clinker. They are fixed on a drive system, close to which a dust trap is made from several parts. One of them is exposed to very high abrasion and temperature, and could ideally be protected with HD8 coatings. Furthermore, the nozzle ring around vertical roller mill tables is equally exposed to ex-treme erosion. In general, wearplates such as CDP® 4624 and CDP® 4666 are used and may be sufficient. Nevertheless, when high throughput and ultimate wear protection are required, standard solutions are not resistant enough and HD8 coatings have given optimal results in the past years in Europe.

In the mining industry, HD8 can be used for pro-tecting large excavator wheels used in open mines, just under the buckets. The highest wear is located in this area but maintenance is difficult to perform due to complex access. Bucket teeth for heavy duty shov-els such as draglines can also be protected with HD8.

Case study - Austrian cement plantAt the end of 2013, wear was so severe in the separa-tor cone and roller mill casing of an Austrian cement plant that standard wearplates did not last more than eight months. As HD8 had shown very good results during the field test conducted at the client prem-ises, the customer ordered the complete lining of its equipment.

The project was designed with Autodesk Inventor 3D by the Castolin Services engineers and 28m2 of HD8 coating (6+3) and 9m2 of CDP® 4666 wearplates (6+4) were installed by the customer assisted by Cas-tolin Eutectic welders. This ensured that the joints were protected correctly. The machine health has since significantly increased.

DRAFT Global Cement Magazine February 2015 www.GlobalCement.com

Castolin Eutectic is a global producer of wear protection products and services for heavy industry, with offices in more than 100 countries on five continents. Here it discusses its new HD8 Coating process for very tough wear conditions.

Below: The HD8 Coating process is automatic and highly controlled.

Bottom left: Nozzle ring parts made using HD8.

Bottom right: Vertical roller mill nozzle ring parts can be coated with HD8.