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Evolution of dislocation structure in martensitic steels: the subgrain size as a sensor for creep strain and residual creep life
Author(s) -
Blum Wolfgang,
Götz Gernot
Publication year - 1999
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.199905639
Subject(s) - creep , metallurgy , dislocation , materials science , crystallography , composite material , analytical chemistry (journal) , chemistry , chromatography
The results on the evolution of the dislocation structure in martensitic CrMoV‐steels published by two research groups are shown to be consistent: The steady state dislocation spacings vary in inverse proportion to shear modulus normalized stress, the subgrains grow with strain at a rate which is determined by the initial subgrain size w 0 , the steady state subgrain size w ∞ and the strain rate, independent of the composition of the material. At constant stress and temperature the strain ɛ and the subgrain size w are uniquely related by ɛ = ɛ w ln[log( w 0 / w ∞ )/log( w / w ∞ )] with ɛ w = 0.12. Thus w can be used as a sensor for strain and, if the relation between strain and time is known, for the residual creep life.