Abstract
Influence of temperature and strain rate on ductile crack growth in A508 vessel steel was studied at impact- and/or static-loaded Charpy specimens in temperature range from -60 to 0 °C. Measured ductile crack lengths show the same dependence on fracture deflection for static- and impact-loaded specimens. Stress and strain field in Charpy specimen during loading were therefore computed by finite element method. Plastic deformation and stress triaxiality distribution at the notch root were identical in static- and dynamic-loaded specimens. In the studied temperature and strain rate domain, the micromechanisms and kinetics of ductile crack growth are the same, independent of temperature and strain rate.

Key words
ductile fracture, quantitative fractography, Charpy test, bainitic steel

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