High Speed Steel
For modern industrial production, in particular mass production, machining is one of the most important shaping and forming processes. Almost all tools employed for this purpose are made from high speed steels. The characteristic properties of all high speed steels grades include.
- High working hardness
- High wear hardness
- Excellent toughness
- High retention of hardness and red hardness
Influence of alloying elements on the steel properties:
Carbon: Forms carbides, increases wear resistance, is responsible for the basic matrix hardness.
Tungsten and Molybdenum: Improves red hardnesss, retention of hardness and high temperature strength of the matrix, form special carbides of great hardness.
Vanadium: Forms special carbides of supreme hardness, increase high temperature wear resistance, retention of hardness and high temperature strength of the matrix.
Chromium: Promotes deep hardening, produces readily soluble carbides.
Cobalt: Improves red hardness and retention of hardness of the matrix.
Aluminium: Improves retention of hardness and red hardness. Since it is possible to achieve specific properties by careful adjustment of these alloying elements, we are able to offer the most suitable high speed steel grade for virtually all kinds of application.
High Alloy Steels will gain improved properties by increasing the solidification rate. This gives a fine microstructure and small, well-distributed carbides in the matrix.
During Powder Metallurgy (PM), the melt stream is atomised by nitrogen gas into small droplets with an average size of 50-100 µm. The powder is filled into capsules directly in order to avoid contamination. With hot isostatic pressing (HIP), the powder is consolidated to 100% density.
By using a special refining sequence, the cleanliness of the molten steel is improved prior to atomisation. This results in improved mechanical properties and an extremely low non-metallic inclusion level (SuperClean™).
The HIP'ed PM capsules are hot forged and rolled to smaller bar sizes followed by heat treatment and machining.
PM steels are used in very demanding applications within cold work, plastic and cutting tools.