TY - JOUR
T1 - Yield strength of nitrogen alloyed duplex steels
T2 - Experiments and micromechanical predictions
AU - Horvath, W.
AU - Hofer, H.
AU - Werner, E.
N1 - Funding Information:
This work was supported by the Fonds zur Fijrderung der Wissenschaftlichen Forschung, Project P10128-6TE.
PY - 1997/12
Y1 - 1997/12
N2 - For the prediction of the yield strength of nitrogen alloyed ferritic-austenitic duplex steels, accurate knowledge on the single phases' yield strength and their geometrical arrangement within the duplex microstructure is required. Since the matrix-inclusion character of the phases markedly influences the duplex yield strength σyd, linear models for σyd (Voigt-model) can not serve for an accurate prediction of σyd. A non-linear rule of mixture, however, is a more sophisticated approach to calculate σyd. Micromechanical models combined with finite element computations are efficient tools to accurately predict the influence of the topology of the microstructure on σyd only if the yield strengths of the single phases are distinctly different, i.e. the yield strength ratio of ferrite and austenite, ψ, is larger than 2. Experiments on duplex steels show, however, a marked influence of the phase arrangement on σyd even for ψ ∼ 1. To explain this behavior a modified non-linear rule of mixture is proposed, which incorporates the in situ yield strengths of the phases as upper and lower bounds for σyd. A Hall-Petch analysis, which considers the interactions between adjacent grains gives excellent agreement between experiments and computational predictions.
AB - For the prediction of the yield strength of nitrogen alloyed ferritic-austenitic duplex steels, accurate knowledge on the single phases' yield strength and their geometrical arrangement within the duplex microstructure is required. Since the matrix-inclusion character of the phases markedly influences the duplex yield strength σyd, linear models for σyd (Voigt-model) can not serve for an accurate prediction of σyd. A non-linear rule of mixture, however, is a more sophisticated approach to calculate σyd. Micromechanical models combined with finite element computations are efficient tools to accurately predict the influence of the topology of the microstructure on σyd only if the yield strengths of the single phases are distinctly different, i.e. the yield strength ratio of ferrite and austenite, ψ, is larger than 2. Experiments on duplex steels show, however, a marked influence of the phase arrangement on σyd even for ψ ∼ 1. To explain this behavior a modified non-linear rule of mixture is proposed, which incorporates the in situ yield strengths of the phases as upper and lower bounds for σyd. A Hall-Petch analysis, which considers the interactions between adjacent grains gives excellent agreement between experiments and computational predictions.
KW - Hall-Petch analysis
KW - Micromechanical modeling
KW - Nitrogen alloyed duplex steels
KW - Rule of mixture
KW - Yield strength
UR - http://www.scopus.com/inward/record.url?scp=0031360779&partnerID=8YFLogxK
U2 - 10.1016/s0927-0256(97)00060-8
DO - 10.1016/s0927-0256(97)00060-8
M3 - Article
AN - SCOPUS:0031360779
SN - 0927-0256
VL - 9
SP - 76
EP - 84
JO - Computational Materials Science
JF - Computational Materials Science
IS - 1-2
ER -