フェライト–パーライト複合組織鋼における降伏点現象のマルチスケール有限要素解析

Yield-point phenomena in Ferrite-Pearlite duplex steels were investigated using multi-scale computational simulations. In this multi-scale simulations, stress--strain relationship of Ferrite phase was characterized by an elastoplastic constitutive model considering yield-drop behavior and its material constants were determined by minimizing residual error between a computational simulation and experiment of tensile test, where yield-point phenomenon in a tensile test of Ferrite steel was reproduced. Using the determined material response of Ferrite phase, finite element analyses of Ferrite-Pearlite duplex microstructure were performed to examine its macroscopic material response and its microscopic deformation mechanism. Besides, finite element analyses of tensile test based on the numerical results of microscopic finite element analysis were conducted to reproduce yield-point phenomena in Ferrite--Pearlite duplex steels.