Laser hardening of tool steel

Laser hardening is a process using very high temperatures to change the microstructure of metals. A laser beam is directed at the steel’s surface and heats it close to its melting point, typically 900-1400 °C. This changes the grain to an austenitic structure.

The hot steel cools so rapidly that the steel is quenched, and a fine-grained microstructure called martensite is formed. This martensite zone can be as deep as 2 mm, improving the steel’s hardness and resistance to wear.

Laser hardening is used for a variety of applications, from press-forming tools to engine components and oil-drilling machinery. By locally increasing the wear resistance it extends the service life of parts. The technology is especially well suited when it is crucial to introduce as little heat into the surrounding material as possible. Cast iron and other ferrous materials, such as hardenable steels, are commonly transformed via laser hardening.

Laser hardening of Toolox^® steels gives exceptionally good results due to its high yield strength. It improves the lifetime of machine components working under highly challenging conditions. The laser hardened surfaces has the further advantage of being very smooth. This reduces friction and the risk for material sticking to the surface. To further enhance the hardness of the surface, carbon powder can be used to cover the metal surface during the process. In this way, In this way, a hardness of 700 HV can be reached on Toolox^® 46, 600 HV on Toolox^® 44 and 500 HV on Toolox^® 33.The hardness level is maintained in a layer to above 1 mm thickness.

A homogeneous steel with high surface quality and uniform characteristics is ideal for all kinds of surface treatments. Toolox^® engineering and tool steel from SSAB fulfil your strictest demands for laser hardening and other surface treatment techniques.