Objetivo
The maximal strength level for a given steel composition can be realised with the martensitic microstructure. However, as-quenched martensite shows some major drawbacks such as low formability and low toughness level. Tempering at a relatively low temperature and/or keeping a certain amount of residual austenite in the microstructure could improve these properties.
Furthermore, an additional low temperature galvanising treatment will provide an additional corrosion resistance to the hot rolled high strength strips. This development will allow the production of coated ultrahigh strength hot rolled steel (TS higher than 1000MPa) with superior formability and toughness level.