600 - 649 Warmfeste und hochwarmfeste Stähle

SEW 605: The weight reduction of vehicle components has led to more filigree components and the use of high-strength materials. Conventional solutions with heat-treatable steels do not always fulfil all requirements in terms of technical reliability, cost-effectiveness and environmental friendliness. Continuously cooled bainitic steels, as can be produced as a result of hot forming in the austenite area, are in some cases much better able to combine the aforementioned aspects, which has led to the successful introduction of such components in the automotive industry over the last decade. This trend is reflected in a large number of commercially available bar steel and wire rod products. To ensure the required hardenability, these products are characterised by increased manganese content, sometimes in combination with chromium, molybdenum and nickel. Such steels are not described in any existing material standard today. This steel-iron material sheet provides customers with a general description of this new class of steel. In naturally cooled steel products, the cooling rate varies depending on the part geometries (or bar steel diameters). In order to be able to set constant properties, the steel composition (in particular the manganese and chromium content) is adapted to the respective natural cooling rates. Even though the steel concept described has been established for a long time and key patents have already expired, some commercially available steels have been specially modified for certain processes and are protected by patent applications.