Thanks to Raex wear-resistant steel, customers can make products that are significantly lighter and have better abrasion resistant properties than traditional structures.

The Raex steels of Ruukki have been made for the most demanding of conditions, where steel structures are exposed to high abrasive wear and surface pressure. The most typical applications are excavator buckets, the wearing parts of mining machines, the wearing parts of concrete mixing plants and wood processing machines, various platform structures, feeders and funnels. Thanks to Raex, customers can make products that are significantly lighter and have better abrasion resistant properties than traditional structures.

A recent demonstration of the excellent wear resistance of Raex 400 was its selection as the platform material for Caterpillar articulated dump trucks. As a result of its hardness, Raex is suitable for all platform structures that are exposed to wear and tear. One of the most demanding applications of wear-resistant steel grades are the platform structures of articulated dump trucks, where the structures are constantly exposed to impacts and
high abrasion.

The strict approval testing was carried out at the CAT Peterlee production facility in the UK, where the Ruukki Group's articulated dump trucks are manufactured for the global markets. The approval process included the testing of chemical, mechanical and impact resistance and the macro testing of the welds.

Advantages through direct quenching

Ruukki manufactures Raex in a direct quenching process where the product is hardened i.e, quenched directly at the rolling mill. This allows for a good surface quality, since no oxidation occurs on the surface, contrary to the traditional hardening process in which the steel is reheated before quenching.

The process is fast and flexible since the products are delivered directly from the rolling mill. Unlike its competitors, Ruukki can also complete the hardening process at the strip rolling mill, due to which it can provide its customers with wear-resistant sheet steel products.

Ruukki offers a wide range of dimensions, from thin 2 mm Raex sheets to thick plates. Sheets that are customised to the customer's dimensions can be cut from direct-quenched strips up to the length of 13 m.

The Ruukki Uusikaupunki production unit is also equipped to laser weld strips into wider plates with an almost invisible weld. This allows the production of thin, wide wear-resistant steel plates, which bring added value to the manufacture of earthmover vehicles. If required, different steel grades and sheet thicknesses can be joined by laser welding.

Thanks to the thin steel sheets, lighter wear-resistant structures can be manufactured. This results in lighter vehicle platforms, decreased fuel consumption and an increased payload, in addition to cost-savings in the manufacturing materials.

Material of choice

From the viewpoint of the end user, the excellent wear resistance properties of Raex will mean the decreased wear of structural components, which in turn will result in the longer service life of components and machinery. Raex is your material of choice for innovative engineering and light-weight structures with enhanced energy efficiency.

"The thin wear-resistant steel provides engineers with a free hand to explore innovative solutions that could not be materialised with traditional materials. An innovative engineer, therefore, plays the key role in making the most out of the new materials," says Hannu Indr?n, Application Manager of Ruukki.

Raex wear-resistant steel is available in four classes of hardness. The available steel grades and hardnesses are Raex 300, Raex 400, Raex 450 and Raex 500.

"When using Raex, the thickness of the structure can usually be decreased by 30-50 per cent, compared to ordinary structural steel, and no compromise on abrasion resistance is needed. The hardness Class 400 is the most commonly used at the global level but there is also an increasing demand for 450. Both steel grades have good formability and weldability, in addition to excellent wear resistance properties," says Indr?n.

Ruukki also provides its customers with Raex flat cut shapes and components ready for installation. This will reduce the customers' material and manufacturing costs and shorten production lead times. Products can also be ordered shop-primed, bevelled and bent. Ruukki has steel service centres in Finland, Poland and Russia. The steel service centres also deliver products to remote export areas. Thanks to the storages of Ruukki and its partners, Raex plates are even available in small numbers and with short delivery times. This way, Ruukki can serve its customers in all the main Raex export countries.