Microstructural modeling of crack nucleation and propagation in high strength martensitic steels

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:51

Article

Wu, Q.¹  Zikry, M. A.¹ 

[1] N Carolina State Univ, Dept Mech & Aerosp Engn, Raleigh, NC 27695 USA

关键词: Dislocation-density;    Lath martensite;    Retained austenite;    Crack nucleation;   

DOI  :  10.1016/j.ijsolstr.2014.08.021

来源: Elsevier

【 摘 要 】

A dislocation-density based multiple-slip crystalline plasticity formulation, a dislocation-density grain boundary (GB) interaction scheme, and an overlapping fracture method were used to investigate crack nucleation and propagation in martensitic steel with retained austenite for both quasi-static and dynamic loading conditions. The formulation accounts for variant morphologies, orientation relationships, and retained austenite that are uniquely inherent to lath martensitic microstructures. The interrelated effects of dislocation-density evolution ahead of crack front and the variant distribution of martensitic blocks on crack nucleation and propagation are investigated. It is shown that dislocation-density generation ahead of crack front can induce dislocation-density accumulations and plastic deformation that can blunt crack propagation. These predictions indicate that variant distribution of martensitic blocks can be optimized to mitigate and potentially inhibit material failure. (C) 2014 Elsevier Ltd. All rights reserved.

【 授权许可】

Free