"Direct quenching, or direct tempering, is a unique breakthrough in the manufacturing of high-strength steels. Production volumes have exceeded our original estimates by over a hundred times. We have been able to expand our operations to new market areas, including China, South America, Australia and South Africa, relates Peter Sandvik, VP Special Projects at Ruukki.
Product development took time and required significant investments over the years. The direct quenching or direct tempering method developed at Ruukki can be considered one of the most important inventions in the steel industry. The basic idea is that hot-rolled steel is quenched from a temperature of around 900 degrees to ambient temperature immediately after rolling. Energy is saved by cutting out the re-heating stage after the hot-rolling. Accelerated cooling gives steel an extremely hard and strong microstructure.
Lighter and stronger products
A direct quenched steel product is energy efficient. The method can be used to manufacture hot rolled strips in the thicknesses of just 2 or 2.5 millimetres. The benefits of lightness include higher payloads, and the strength gives the product a longer life cycle. Ruukki’s customers have achieved weight savings of up to 20-30 per cent in heavy vehicles which, on top of fuel savings, has made it possible to increase the payload by 4-7 per cent.
Typical applications for direct quenched steel include lifting equipment, trucks and busses, rolling stock and steel armour plates.
Products manufactured using the direct quenching technology represent an important share in Ruukki’s special steel qualities, which currently make up nearly one third of the company’s steel business.
Winner of the Finnish Engineering Award
The direct quenching technology developed by Ruukki received the Finnish Engineering Award 2012. This award is presented annually by the Academic Engineers and Architects in Finland TEK and Tekniska Föreningen i Finland TFIF.
”The award is a superb recognition to both the inventors and the entire work community. Product development, production and sales worked closely together on this project. The production side proved its flexibility, particularly when the new technology was being tested. Sales, on the other hand, played a key role in identifying pilot customers. This has been teamwork at its best”, says Sandvik.
”Tekes funding enabled us to conduct our research together with universities and contributed greatly to our success story”, Sandvik continues.
VP, Special Products
tel. 020 592 9113
Author: Tiina Lifländer
Photo: Ruukki Metals