R. Kawalla et al., SIMULATION OF MATERIAL FLOW AND MICROSTRUCTURAL EVOLUTION DURING THE HOT-ROLLING OF FLAT PRODUCTS, Journal of materials processing technology, 45(1-4), 1994, pp. 477-484
A simulation system is presented in which the FEM calculation of the m
aterial flow is coupled on-line with simulation of the microstructural
changes that occur during the hot rolling of steel to produce flat pr
oducts. The local forming parameters and temperatures of the material
concerned are determined by FEM simulation for the individual forming
passes and used as the basis for advance calculation of the local micr
ostructural changes using the metallurgically-oriented model. The latt
er takes account of factors such as austenitic grain growth on heating
, recrystallization processes in the austenite during hot forming and
in the intervals between forming as well as the gamma/alpha transforma
tion during cooling after hot forming. The suitability of the simulati
on system for use in solving operational problems is shown by discussi
ng an example taken from the area of hot strip production. The authors
investigate the reasons for the microstructural inhomogeneities obser
ved over the thickness of the strip. In addition, a critical appraisal
is made of the widespread practice of effecting microstructural simul
ations with global forming parameters derived from the change in the e
xternal dimensions of the rolled material, instead of using local valu
es.