R-Curves and Fracture Toughness Transition Behaviour at Static, Rapid and Impact Loading of Cr-Ni-Mo-V Reactor Pressure Vessel Steel

R-Curves and Fracture Toughness Transition Behaviour at Static, Rapid and Impact Loading of Cr-Ni-Mo-V Reactor Pressure Vessel Steel

Článek recenzovaný mimo WoS a Scopus

The fracture toughness of Cr-Ni-Mo-V reactor pressure vessel steel was investigated over a wide temperature range. In the upper shelf fracture toughness region, R-curves were determined using large SEN bending specimens and small side-grooved precracked Charpy sepecimens. Two approaches were used for the evaluation of the fracture toughness scatter in the transition and in the lower shelf fracture toughness region: the exponential function with a least-squares regression procedure for a fracture toughness-temperature data and Weibull statistics for a fracture toughness data set obtained at the given temperature. The investigation of the influence of loading rate, ranging from 1 . 0 MPa m(1/2)s(-1) (static) to 3 X 10(4) MPa m(1/2) s(-1) (most rapid), on the behaviour of fracture toughness has shown a shift of cleavage/fibrous transition temperature by 60 degrees C. In contrast to that, at impact loading using a precracked Charpy specimen (K-1 = 2 X 10(5) MPa m(1/2) s(-1)) the shift of this transition temperature was only 30 degrees C, and a sudden transition of fracture toughness occurred from the lower shelf to the upper shelf toughness region.

The fracture toughness of Cr-Ni-Mo-V reactor pressure vessel steel was investigated over a wide temperature range. In the upper shelf fracture toughness region, R-curves were determined using large SEN bending specimens and small side-grooved precracked Charpy sepecimens. Two approaches were used for the evaluation of the fracture toughness scatter in the transition and in the lower shelf fracture toughness region: the exponential function with a least-squares regression procedure for a fracture toughness-temperature data and Weibull statistics for a fracture toughness data set obtained at the given temperature. The investigation of the influence of loading rate, ranging from 1 . 0 MPa m(1/2)s(-1) (static) to 3 X 10(4) MPa m(1/2) s(-1) (most rapid), on the behaviour of fracture toughness has shown a shift of cleavage/fibrous transition temperature by 60 degrees C. In contrast to that, at impact loading using a precracked Charpy specimen (K-1 = 2 X 10(5) MPa m(1/2) s(-1)) the shift of this transition temperature was only 30 degrees C, and a sudden transition of fracture toughness occurred from the lower shelf to the upper shelf toughness region.

HOLZMANN, M.; MAN, J.; VÁLKA, L.; VLACH, B.

01.01.1995

0308-0161

INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING

62

1

Spojené království Velké Británie a Severního Irska

39

47

9