Master Curve Reference Temperature Determination Using Small Low-Constraint Specimens

Abstract The constraint correction methodology for defect assessment is not widely applied in fitness-for-service codes in the nuclear industry and there are no testing standards to account for low-constraint testing in the ductile-to-brittle transition region. The objective of this investigation is to illustrate an improved testing and evaluation methodology to obtain a low-constraint reference temperature T0 fulfilling improved quality criteria. Two types of specimen geometries are investigated: 10 × 10 mm2 cross-section single edge bend (SE(B)) and single edge tension (SE(T)) specimens with shallow and conventional a/W ratios, allowing for varying levels of constraint. New quality assurance measures related to the selection of testing temperature, crack front straightness, and compliance for low-constraint specimens are applied. This work impacts the development of quality criteria for future low-constraint testing standards.