Correlation of Charpy Impact Energy and Fracture Toughness for Low Alloy Structural Steel Welds

Author(s):  
Kleber Eduardo Bianchi ◽  
Vitor Scarabeli Barbosa ◽  
Paulo Fernandes ◽  
Claudio Ruggieri
2021 ◽  
Vol 113 ◽  
pp. 102934
Author(s):  
Vitor S. Barbosa ◽  
Lucas A.C. de Godois ◽  
Kleber E. Bianchi ◽  
Claudio Ruggieri

2013 ◽  
Vol 32 (2) ◽  
pp. 163-169
Author(s):  
Josip Brnic ◽  
Goran Turkalj ◽  
Sanjin Krscanski

AbstractThis paper presents and analyzes the responses of non-alloy structural steel (1.0044) subjected to uniaxial stresses at high temperatures. This research has two important determinants. The first one is determination of stress-strain dependence and the second is monitoring the behavior of materials subjected to a constant stress at constant temperature over time. Experimental results refer to mechanical properties, elastic modulus, total elongations, creep resistance and Charpy V-notch impact energy. Experimental results show that the tensile strength and yield strength of the considered material fall when the temperature rises over 523 K. Significant decrease in value is especially noticeable when the temperature rises over 723 K. In addition, engineering assessment of fracture toughness was made on the basis of Charpy impact energy. It is visible that when temperature raises then impact energy increases very slightly.


Author(s):  
Kleber E. Bianchi ◽  
Vitor Scarabeli Barbosa ◽  
Rafael Savioli ◽  
Paulo Eduardo Alves Fernandes ◽  
Claudio Ruggieri

Correlations between Charpy impact energy and fracture toughness values have continuously been developed because of their applicability in structural integrity assessment methodologies. This also applies to the integrity analysis of welded joints, which represent material discontinuities and potential failure locus in structures. Therefore, in effective FFS methodology applications, the fracture toughness of welded joints located in critical regions should be accurately estimated. This work addresses an estimation procedure of fracture toughness values based on Charpy impact energy for low alloy, steel welds made from an ASTM A572 Gr 50 base plate material. To produce the welded joints, two processes were used: SMAW and FCAW. To ensure valid toughness test values corresponding to high constraint conditions, a strength overmatched, deeply-cracked SE(B) configuration having a weld centerline notch was adopted. The ductile-to-brittle transition curve was established by means of Charpy tests. Direct CVN correlations with fracture toughness, as well as reference temperature based correlations derived from the Master Curve approach, were evaluated. The obtained results indicate that both correlation procedures are suitable for weld metal toughness estimations based on Charpy data. However, slightly different values of correlation constants than those indicated for the base metal should be employed in the case of the reference temperature method.


1977 ◽  
Vol 99 (3) ◽  
pp. 419-426
Author(s):  
R. R. Seeley ◽  
W. A. Van Der Sluys ◽  
A. L. Lowe

Large bolts manufactured from SA540 Grades B23 and B24 are used on nuclear reactor vessels and require certain minimum mechanical properties. A minimum fracture toughness of 125 ksi in. (137 MPa m) at maximum operating stresses is required by the Nuclear Regulatory Commission for these bolts. This minimum toughness property was determined by a stress analysis of a bolt. Minimum required Charpy impact properties were calculated by a fracture toughness-Charpy impact energy correlation and the minimum calculated fracture toughness. The fracture toughness, yield strength and Charpy V notch impact properties were determined for five commercial heats of SA540 steels. Correlations between the fracture toughness and Charpy impact properties of these materials were evaluated. The toughness-impact energy correlation used to set the minimum required Charpy impact properties was found to be unduly conservative, and a different correlation of these properties is suggested. The SA540 steels investigated exhibited fracture toughness properties in excess of the NRC minimum requirements.


Author(s):  
Guang-Li Zhang ◽  
Xin-Wei Zhao ◽  
Jin-Heng Luo ◽  
Shao-Tao Gong ◽  
Hua Zhang ◽  
...  

According to the linear regression analysis, a new empirical equations between the fracture toughness (KIc) and Charpy impact energy (CVN) of X80 high strength pipeline steel, were developed on the basis of experiment sample data. And the theory of statistical test was used to test the significance of the new equation. The test result indicated that the new empirical equation has very high significance with the sample data. Comparing with the empirical equation recommended by the API 579-2007, the empirical equation developed here was more suitable for the X80 high strength pipeline steel, and can make better estimation for the fracture toughness of X80. And for the estimation of fracture toughness of X100 high strength pipeline steel, the equation developed here is applicable too.


2016 ◽  
Vol 138 (4) ◽  
Author(s):  
O. K. Chopra ◽  
A. S. Rao

Cast austenitic stainless steel (CASS) materials, which have a duplex structure consisting of austenite and ferrite phases, are susceptible to thermal embrittlement during reactor service. In addition, the prolonged exposure of these materials, which are used in reactor core internals, to neutron irradiation changes their microstructure and microchemistry, and these changes degrade their fracture properties even further. This paper presents a revision of the procedure and correlations presented in NUREG/CR-4513, Rev. 1 (Aug. 1994) for predicting the change in fracture toughness and tensile properties of CASS components due to thermal aging during service in light water reactors (LWRs) at 280–330 °C (535–625 °F). The methodology is applicable to CF-3, CF-3M, CF-8, and CF-8M materials with a ferrite content of up to 40%. The fracture toughness, tensile strength, and Charpy-impact energy of aged CASS materials are estimated from known material information. Embrittlement is characterized in terms of room-temperature (RT) Charpy-impact energy. The extent or degree of thermal embrittlement at “saturation” (i.e., the minimum impact energy that can be achieved for a material after long-term aging) is determined from the chemical composition of the material. Charpy-impact energy as a function of the time and temperature of reactor service is estimated from the kinetics of thermal embrittlement, which are also determined from the chemical composition. The fracture toughness J-R curve for the aged material is then obtained by correlating RT Charpy-impact energy with fracture toughness parameters. A common “predicted lower-bound” J-R curve for CASS materials of unknown chemical composition is also defined for a given grade of material, range of ferrite content, and temperature. In addition, guidance is provided for evaluating the combined effects of thermal and neutron embrittlement of CASS materials used in the reactor core internal components. The correlations for estimating the change in tensile strength, including the Ramberg/Osgood parameters for strain hardening, are also described.


Author(s):  
Carey L. Walters ◽  
Kim Wallin

This paper gives the theoretical basis for a new method of using Charpy data to estimate fracture toughness in the transition region by using both fracture surface appearance and the traditional Charpy energy. Prior research has shown that the Charpy energy and fracture surface appearance can be used to estimate the upper-shelf J-integral [1]. The current paper extends those ideas by using that same information not to estimate upper-shelf Charpy energy, but to estimate the toughness of fracture mechanics specimens at the same temperature.


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