基于特征组织元法的氢气扩散数值模拟研究OA

Duplex stainless steel,which combined the excellent comprehensive properties of austenite and ferrite phases,was widely applied in harsh corrosive environments such as marine engineering,and hydrogen-induced cracking(HIC)was the dominant failure mode during its service life.However,the traditional Voronoi model was unable to accurately characterize the morphology and phase boundary features of the duplex microstructure,which led to severe limitations in the prediction accuracy of hydrogen diffusion behavior simulation.In this paper,the Feature Organizing Element Method(FOEM)was applied to the research on HIC of duplex stainless steel for the first time.Aiming at the core defects of the traditional model,a novel FOEM-based modeling method via metallographic image reconstruction was proposed.Equiaxed grains and columnar grains were adopted to match the structural characteristics of ferrite and austenite phases respectively,and a cross-scale correlation model linking the microstructure and macroscopic mechanical behavior was constructed.Numerical simulations of hydrogen diffusion and release behavior were performed based on the established model,which accurately reproduced the preferential diffusion paths and concentration distribution rules of hydrogen atoms in the duplex microstructure.The simulation results were in high consistency with the theoretical predictions,and the prediction accuracy of hydrogen concentration was significantly improved.The results demonstrated that the FOEM had great application potential in HIC research,provided novel theoretical support for the hydrogen embrittlement resistance design of duplex stainless steel,and realized the interdisciplinary integration of material computation and corrosion protection.