A Method for Determining the Crack Arrest Fracture Toughness of Ferritic Materials

2009 ◽  
pp. 569-569-25
Author(s):  
DB Barker ◽  
R Chona ◽  
WR Corwin ◽  
WL Fourney ◽  
GR Irwin ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Crack Arrest

The Crack Arrest Capability of 9-Percent Ni Steels (ASTM 553, Type 1) LNG Storage Tanks

1991 ◽  
Vol 113 (3) ◽  
pp. 380-384
Author(s):  
P. B. Crosley ◽  
E. J. Ripling
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
High Stress ◽  
Crack Arrest ◽  
Storage Tanks ◽  
Membrane Stress ◽  
High Stress Region ◽  
Fast Running ◽  
Stress Region

Safety of structures can be assured, even if cracks initiate in localized regions of abnormally low toughness, and/or abnormally high stress (LT/HS), if the materials from which they are fabricated have a high enough crack arrest fracture toughness. When this requirement is met, fast-running cracks that initiate in LT/HS regions arrest when their tip encounters material having normal toughness and stresses. The work described in this paper was carried out to determine the crack arrest capability of LNG storage tanks by determining the longest LT/HS region in which a crack could initiate and still arrest when it leaves this region. The determination consisted of relating a fracture analysis with the measured full-thickness crack arrest fracture toughness of three 9-percent Ni plates which were reported in reference [1]. The calculations used a residual stress pattern, produced by welding, superimposed on a typical membrane stress. The residual stress was selected as an example of a localized high stress region. It was found that tanks built from the poorest of the three tested plates could arrest cracks about 3/4 m long, while tanks built from the two tougher plates could arrest cracks almost 2 m long.

Comparison of crack-arrest fracture toughness between low and high heat-input thick weld specimens

2015 ◽  
Vol 194 (2) ◽  
pp. 197-203 ◽  
Author(s):  
Gyu Baek An ◽  
Wanchuck Woo ◽  
Jeong Ung Park ◽  
Vyacheslav Em
Keyword(s):  
Fracture Toughness ◽  
Heat Input ◽  
Crack Arrest ◽  
High Heat ◽  
High Heat Input

Crack Arrest Fracture Toughness Testing of Naval Construction Steels

1998 ◽  
Vol 26 (3) ◽  
pp. 269 ◽  
Author(s):  
DR Petersen ◽  
IA Burch ◽  
JC Ritter ◽  
DS Saunders ◽  
JH Underwood
Keyword(s):  
Fracture Toughness ◽  
Crack Arrest ◽  
Fracture Toughness Testing ◽  
Toughness Testing

Fracture Mechanics at Elevated Loading Rates in the Ductile to Brittle Transition Region

2017 ◽  
Author(s):  
Uwe Mayer ◽  
Thomas Reichert ◽  
Johannes Tlatlik
Keyword(s):  
Fracture Toughness ◽  
Dynamic Loading ◽  
Dynamic Fracture ◽  
Master Curve ◽  
Crack Arrest ◽  
Dynamic Fracture Toughness ◽  
Fracture Probability ◽  
High Rate ◽  
Loading Rates ◽  
Static Conditions

The rate-dependent reference temperature T0,x characterizes the fracture toughness of ferritic steels at the onset of cleavage. Fracture toughness values KJc,d were determined according to the Annex A1 of ASTM E1921 [1] which refers to the high rate annexes A14 and A17 of ASTM E1820 [2]. Results of extensive dynamic fracture toughness experiments at various loading rates, temperatures, specimen types and sizes revealed shortcomings in the transferability of the shape of the Master Curve under quasi-static conditions to elevated loading rates. In particular, the quasi-static Master Curve predicts lower fracture toughness values towards higher temperatures than experimentally observed under dynamic loading causing a steeper Master Curve shape. Fractographic examinations proved the relevance of local crack arrest under dynamic loading conditions, which is consistent with the view of the parallelism of dynamic fracture probability and probability of arrest.

Crack Arrest Test Results of Unirradiated and Irradiated German RPV Steels

2013 ◽  
Author(s):  
Florian Obermeier ◽  
Julia Barthelmes ◽  
Elisabeth Keim ◽  
Hieronymus Hein ◽  
Hilmar Schnabel ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Lower Bound ◽  
Pressure Vessel ◽  
Charpy Impact ◽  
Crack Arrest ◽  
Reactor Pressure Vessel ◽  
Test Method ◽  
Fracture Toughness Test ◽  
Test Results ◽  
Reactor Pressure

In the CARISMA[1] and CARINA[2] projects comprehensive tensile, Charpy-impact and fracture toughness tests were performed for unirradiated and irradiated original reactor pressure vessel (RPV) steel specimens from German pressurized water reactors (PWR) up to neutron fluences in the range of 60 operational years and beyond. In addition, crack arrest fracture toughness tests were performed to demonstrate the crack arrest behavior of the materials. To determine the crack arrest properties of ferritic steels, the designated test method according to ASTM E1221 [3] was used. However, in particular for irradiated reactor pressure vessel materials with higher irradiation embrittlement, the prescribed standard test specimen does not always provide adequate test results. During starter notch preparation annealing effects occurred in the heat affected zone (HAZ) of the brittle weld of the starter notch causing crack arrest in the HAZ after unstable crack initiation. Therefore a modified test method to perform crack arrest tests with so called duplex specimens was investigated. In this paper this modified method and the test results of five base and four weld metals with a fluence up to 4,69E+19 cm−2 (E >1 MeV) are discussed. The available test results show that the duplex specimen is an appropriate alternative to the standard compact crack arrest (CCA) specimen. The measured KIa fracture toughness data are enveloped by the “lower bound” of the ASME KIa-curve indexed with RTNDTj or TKIa but not all data are enveloped by indexing the “lower bound” curve with RTT0 like described in the ASME Code Case N-629 [4]. Furthermore correlations of the crack arrest test results with Charpy-impact and fracture toughness test results will be shown.

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