Ruukki Raex® range has 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, as well as various platform structures, feeders and funnels.

Due to Raex, Ruukki’s global clientele can now 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,” says Ruukki Application Manager Hannu Indrén.

“As a result of its hardness, Raex is suitable for all platform structures that are exposed to wear and tear. And one of the most demanding applications of wear-resistant steels grades are the platform structures of articulated dump trucks, where the structures are constantly exposed to impacts and high abrasion.”

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

Ruukki manufactures Raex in a direct quenching process where the product is quenched right 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,” says Hannu.

“The process is fast and flexible since the products are delivered directly from the rolling mill. And unlike our competitors, we can also complete the hardening process at the strip rolling mill. Therefore, we can also offer wear-resistant sheet steel products.”

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

Ruukki’s production site in Uusikaupunki, Finland is also equipped with specialised machinery 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, we can even join different steel grades and sheet thicknesses,” says Hannu.

As a result, Ruukki’s clientele is now able to realise lighter, yet wear-resistant structures. This, in turn, allows for lighter vehicle platforms, decreased fuel consumption and an increased payload, in addition to cost-savings in the manufacturing materials.

“From an end user’s point of view, the excellent wear resistance properties of Raex will mean decreased wear of structural components, which in turn will result in a longer service life of components and machinery,” Hannu explains. “Raex is your material of choice for innovative engineering and light-weight structures with enhanced energy efficiency.

“The thin wear-resistant steel gives engineers around the globe more freedom to explore innovative solutions that could not be realised with traditional materials. An innovative engineer, therefore, plays the key role in making the most out of the new materials,” he adds.