Multiscale representation of the microstructure evolution and the mechanical properties of steel grade DC04 during the production process
After casting, the process chain for the production of semi-finished sheet metals consists of different process steps like hot-rolling, cold-rolling, heat treatment, and skin pass rolling. Thereafter, the semi-finished part is manufactured to a component by sheet metal forming operations like deep drawing. During such process chains, a strong evolution of the microstructure and the resulting mechanical properties can be observed. Due to the occurring finite plastic deformations and the accompanied increase in dislocation density during the cold rolling process, the grain structure is extremely deformed and the orientations of the grains are changed. In contrast to hot-rolled metals, the cold-rolled material shows recrystallization by temperature rise. The recrystallization processes are required to adjust the mechanical behaviour of the annealed material. For process optimization, it is essential to understand the combined process of cold-rolling and annealing: i.e. how the microstructure like the grain orientations evolves and also how that influences the mechanical behaviour. Only detailed knowledge about the microstructural evolution enables to find the optimal design of such process chains. During component production by deep drawing, the resulting material properties of the semi-finished product influence strongly the material behaviour in the manufacturing process.