University of Oulu

Yang Li, Sakari Pallaspuro, Xiaobo Ren, Jianying He, Jukka Kömi, Zhiliang Zhang, A multi-barrier model assisted CAFE method for predicting ductile-to-brittle transition with application to a low-carbon ultrahigh-strength steel, Mechanics of Materials, Volume 153, 2021, 103669, ISSN 0167-6636,

A multi-barrier model assisted CAFE method for predicting ductile-to-brittle transition with application to a low-carbon ultrahigh-strength steel

Saved in:
Author: Li, Yang1,2; Pallaspuro, Sakari3; Ren, Xiaobo4;
Organizations: 1School of Architecture and Civil Engineering, Xi'an University of Science and Technology, No.58 Yanta Road, Xi'an, 710054, China
2NTNU Nanomechanical Lab, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), Richard Birkelands Vei 1A, N-7491, Trondheim, Norway
3Materials and Mechanical Engineering, Centre for Advanced Steels Research, University of Oulu, Pentti Kaiteran Katu 1, FI-90570, Oulu, Finland
4SINTEF Industry, Richard Birkelands Vei 2B, N-7465, Trondheim, Norway
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 11.2 MB)
Persistent link:
Language: English
Published: Elsevier, 2020
Publish Date: 2021-01-11


The conventional micromechanical approaches today are still not able to properly predict the ductile-to-brittle transition (DBT) of steels because of their inability to consider the co-operating ductile fracture and cleavage mechanisms in the transition region, and simultaneously to incorporate the inherent complexity of microstructures. In this study, a complete methodology with coupled cellular automata finite element method (CAFE) and multi-barrier microcrack propagation models is presented to advance the prediction of DBT. The methodology contains three key elements: (i) a multiscale CAFE modelling approach to realize the competition between ductile damage and cleavage fracture and embrace the probabilistic nature of microstructures, (ii) a continuum approach to estimate the effective surface energy for a microcrack to penetrate over particle/matrix interface, and (iii) a method to calculate the effective surface energy for the microcrack to propagate across grain boundaries. The prediction of DBT therefore needs only (1) the stress-strain curves tested at different temperatures, (2) the activation energy for DBT, (3) the ratio between the size of cleavage facets and cleavage-initiating defects, and (4) key statistical distributions of the given microstructures. The proposed methodology can accurately reproduce the experimental DBT curve of a low-carbon ultrahigh-strength steel.

see all

Series: Mechanics of materials
ISSN: 0167-6636
ISSN-E: 1872-7743
ISSN-L: 0167-6636
Volume: 153
Article number: 103669
DOI: 10.1016/j.mechmat.2020.103669
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
213 Electronic, automation and communications engineering, electronics
222 Other engineering and technologies
Funding: The Research Council of Norway is thanked for the funding through the Petromaks 2 Programme, Contract No. 228513/E30. The authors also wish to thank the financial support by the National Natural Science Foundation of China (Grant No. 51404294) and Academy of Finland (Grant No. 311934).
Copyright information: © 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (