PSI - Issue 13

Vitor Scarabeli Barbosa et al. / Procedia Structural Integrity 13 (2018) 367–372 Author name / Structural Integrity Procedia 00 (2018) 000 – 000

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Table 2. Maximum likelihood estimates of the characteristic, Ĵ 0 , for the measured distributions of the J c -values of each PCVN configuration, including the 1T-SE(B) standard configuration, and the corresponding estimates for T 0 -values. Geometry S/W Ĵ 0 (kJ/m²) T 0 (°C) 1T-SE(B) 4 59 -26 PCVN 4 74 -20 PCVN 6 6 -24 SG-PCVN 6 54 -9 PCVN 8 58 -11 5. Conclusions This study describes the results of a rather extensive fracture testing of an ASTM A572 Gr 50 structural steel using non-standard PCVN specimens and an exploratory application to determine the reference temperature, T 0 , and associated variation of cleavage fracture toughness with temperature for this material. The fracture mechanics tests were performed on conventional, plane-sided SE(B) specimens with a/W = 0 . 5, B = 25 mm, W = 50 mm and S = 4 W loaded under 3-point bending; and (2) plane-sided, precracked Charpy (PCVN) specimen with a/W = 0 . 5, B = 10 mm, W = 10 mm and S = 4 W , 6 W and 8 W . The experimental results show a potential effect of increased span on J c values which can help to mitigate the effects of constraint loss commonly observed in PCVN specimens. An exploratory application to determine the reference temperature derived from the Master Curve approach using fracture toughness values obtained from testing non-standard bend geometries, particularly the PCVN configuration with increased span, produces predictions for 0 which are more conservative than the corresponding reference temperature derived from testing conventional, deeply cracked 1-T SE(B) specimens. Acknowledgements This investigation is supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) through research grant 2016/26024-1. The first author (VSB) would like to acknowledge the financial support from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). The work of CR is also supported by the Brazilian Council for Scientific and Technological Development (CNPq) through grant 306193/2013-2. API RP-579-1/ASME FFS-1, 2016. Fitness-for-Service, American Petroleum Institute, Washington, 668 DC. ASTM E1921-18, 2018. Standard Test Method for Determination of Reference Temperature, T 0 , for Ferritic Steels in the Transition Range . ASTM International, West Conshohocken, PA. Barbosa, V. S., Ruggieri, C., 2018. Fracture toughness testing using non-standard bend specimens – Part I: Constraint effects and development of test procedure. Engineering Fracture Mechanics 195, 279 – 296. McCabe, D. E., Merkle, J. G., Wallin, K., 2005. An Introduction to the Development and Use of the Master Curve Method. ASTM Manual Series: MNL 27, ASTM International. Odette, G. R., Lucas, G. E., 2001. Embrittlement of Nuclear Reactor Pressure Vessels. JOM, 53, 18-22.. Wallin, K., 1991. Fracture toughness transition curve shape for ferritic structural steels, in “Joint FEFG/IICF International Conference on Fracture of Engineering Materials and Structures” . In: Teoh, S. H., Lee, K. H. (Eds.), Singapore, 83 – 88. Wallin, K., 2002. Master Curve Analysis of the Euro Fracture Toughness Dataset. Engineering Fracture Mechanics 69, 451 – 481. References