Papers by Keyword: Microstructural Heterogeneity

Abstract: In the present study, the effects of inclusions on the local ductility of DP steel are investigated using finite element analysis (FEA). In order to evaluate local ductility, a continuum damage mechanics (CDM) model has been incorporated into the Abaqus/Explicit® commercial finite element code. Furthermore, three-dimensional representative volume elements (RVEs) with ferrite, martensite, and inclusion phases have been used to evaluate the stress-strain response. Simulation results show that the volume fraction of the martensite as well as the difference in hardness between the ferrite and the martensite phases dominates the effect of inclusions on local ductility.

Abstract: The microstructural heterogeneities in steels may have different origins. The tendency in industry to decrease the total amount of reduction during hot working decreases the possibilities of applying approaches based on “thermo-mechanical homogenization”. In this situation, alternative approaches need to be evaluated to reduce the heterogeneities present in the initial microstructure and, simultaneously, to avoid the possibility of inducing additional heterogeneities during processing. This paper analyzes the relevance of several processing parameters in different cases.

Abstract: The microstructural evolution during the hot rolling of coarse grain sized austenite has been modeled taking into consideration all the microstructural mechanisms (dynamic, static and metadynamic recrystallization, strain induced precipitation) that could take place during the industrial TSDR production of a Nb microalloyed steel. Based on the results obtained from the model, processing maps have been drawn for a 0.035%Nb microalloyed steel. Optimum processing conditions to exploit all the benefits of Nb microalloying have been defined considering a final gauge thickness range between 1.5 and 12.65 mm.