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Brittle fracture of high‐strength steels at very low temperatures
Author(s) -
RODRÍGUEZMARTÍN R.,
OCAÑA I.,
MARTÍNMEIZOSO A.
Publication year - 2007
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.2007.01131.x
Subject(s) - materials science , brittleness , fracture toughness , brittle fracture , toughness , cleavage (geology) , composite material , fracture (geology) , structural engineering , metallurgy , engineering
High‐strength steels are used to increase the load carrying capacity of components. However, to guarantee a safe design, it is also necessary to combine high strength with adequate fracture toughness. In this paper, fracture toughness of three high‐strength steels with yield strengths ranging from 460 to 890 MPa has been studied at very low temperatures. Taking into account experimental evidence, a new mechanism of cleavage at very low temperatures is proposed. This mechanism considers the possibility of reaching the ideal strength (the stress at which the lattice of a single crystal losses its stability) in the immediate vicinity of the fatigue crack tip. Moreover, a computational model able to calculate the external load needed to produce a catastrophic failure of these steels has been developed.