Publication: Dynamic Master Curve and ductile-brittle transition temperature of 9Cr-1Mo steel
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Date
2005
Journal Title
11th International Conference on Fracture 2005, ICF11
Journal ISSN
Volume Title
Publisher
Abstract
The DBTT of 9Cr-1Mo steel has been characterised by reference temperature (T0) based Master Curve (MC) approach. The MC was developed at the dynamic loading conditions (stress intensity factor change rate ∼ 10 6 MPa√m/s at a loading rate of 5.12 m/s) using pre-cracked Charpy specimens (PCVN) following ASTM E 1921 guidelines. To minimise the inertial oscillations effect on load determination, the initial T0 was determined by tests conducted at a hammer velocity of ∼1.12 m/s; this was further converted toT0 at 5.12 m/s applying an test velocity dependent shift to T0. Thus, the T0 for 9Cr-lMo steel at dynamic condition was determined to be -52 °C Using a modified Schmdler procedure to evaluate KId from instrumented Charpy V-notch tests, T0 was also estimated for the 9Cr-lMo steel and the result shows close agreement with the T0 evaluated from the pre-cracked Charpy tests. ASME KIR-curve approach proves to be too conservative compared to the real trend of the fracture toughness with temperature.