Experimental Research and Analysis of Non-alloy Structural Steel Response Exposed to High Temperature Conditions

2013 ◽  
Vol 32 (2) ◽  
pp. 163-169
Author(s):  
Josip Brnic ◽  
Goran Turkalj ◽  
Sanjin Krscanski
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Structural Steel ◽  
Impact Energy ◽  
Charpy Impact ◽  
Experimental Results ◽  
Charpy Impact Energy ◽  
Over Time

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.

Charpy impact energy correlation with fracture toughness for low alloy structural steel welds

2021 ◽  
Vol 113 ◽  
pp. 102934
Author(s):  
Vitor S. Barbosa ◽  
Lucas A.C. de Godois ◽  
Kleber E. Bianchi ◽  
Claudio Ruggieri
Keyword(s):  
Fracture Toughness ◽  
Structural Steel ◽  
Impact Energy ◽  
Charpy Impact ◽  
Charpy Impact Energy ◽  
Energy Correlation ◽  
Steel Welds

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

2019 ◽  
Author(s):  
Kleber Eduardo Bianchi ◽  
Vitor Scarabeli Barbosa ◽  
Paulo Fernandes ◽  
Claudio Ruggieri
Keyword(s):  
Fracture Toughness ◽  
Structural Steel ◽  
Impact Energy ◽  
Charpy Impact ◽  
Charpy Impact Energy ◽  
Steel Welds

Fracture Toughness Properties of SA540 Steels for Nuclear Bolting Applications

1977 ◽  
Vol 99 (3) ◽  
pp. 419-426
Author(s):  
R. R. Seeley ◽  
W. A. Van Der Sluys ◽  
A. L. Lowe
Keyword(s):  
Fracture Toughness ◽  
Impact Energy ◽  
Nuclear Reactor ◽  
Charpy Impact ◽  
Nuclear Regulatory Commission ◽  
Charpy Impact Energy ◽  
Energy Correlation ◽  
Impact Properties ◽  
Minimum Requirements ◽  
Regulatory Commission

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.

scholarly journals Experiment on Strength and Failure Behavior of Sandstone Containing Pre-Existing Cracks Under Brazilian Compression

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaojian Cao ◽  
Han Zhang ◽  
Jun Yu ◽  
Tianchong Yu ◽  
Yuxing Qing
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Failure Process ◽  
Experimental Results ◽  
Failure Behavior ◽  
Axial Deformation ◽  
Scanning Electron

Determination of the mechanical properties of rock containing pre-existing cracks under tension condition is of great significance to understand the failure process of rock in engineering. This paper presents the experimental results of sandstone containing pre-existing cracks under Brazilian compression. The characteristics of the microcracks were analyzed by a scanning electron microscope. The results show that the rock containing pre-existing cracks has an obvious anisotropic characteristic. When the crack inclination is 45°, the rock has the minimum tensile strength and the weakest axial deformation resistance.

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

2017 ◽  
Author(s):  
Kleber E. Bianchi ◽  
Vitor Scarabeli Barbosa ◽  
Rafael Savioli ◽  
Paulo Eduardo Alves Fernandes ◽  
Claudio Ruggieri
Keyword(s):  
Fracture Toughness ◽  
Impact Energy ◽  
Welded Joints ◽  
Structural Integrity ◽  
Charpy Impact ◽  
Reference Temperature ◽  
Transition Curve ◽  
Charpy Impact Energy ◽  
Integrity Assessment ◽  
Steel Welds

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.

scholarly journals Mechanical Properties of Commercial Purity Aluminum Modified by Zirconium Micro-Additives

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 270
Author(s):  
Ahmad Mostafa ◽  
Wail Adaileh ◽  
Alaa Awad ◽  
Adnan Kilani
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Composition Range ◽  
Charpy Impact ◽  
Strain Hardening Exponent ◽  
Phase Assemblage ◽  
Charpy Impact Energy ◽  
Commercial Purity ◽  
Al3zr Particle ◽  
Commercial Purity Aluminum

The mechanical properties and the fractured surfaces of commercial purity aluminum modified by zirconium micro-additives were investigated by means of experimental examination. A commercial purity Al specimen was used as a reference material and seven Al-Zr alloys in the 0.02–0.14 wt.% Zr composition range (with 0.02 wt.% Zr step) were prepared by microalloying methods. Optical microscopy was used to examine the microstructures and to calculate the grain sizes of the prepared specimens. The phase assemblage diagrams were plotted and the relative amounts of solid phases were calculated at room temperature using FactSage thermochemical software and databases. Proof stress, strength coefficient and strain hardening exponent were measured from the stress-strain curves obtained from tensile experiments and Charpy impact energy was calculated for all specimens. The experiments showed that the grain size of commercial purity Al was reduced by adding any Zr concentration in the investigated composition range, which could be due to the nucleation of new grains at Al3Zr particle sites. Accordingly, the microhardness number, tensile properties and Charpy impact energy were improved, owing to the large grain-boundary areas resulted from the refining effect of Zr, which can limit the movement of dislocations in the refined samples. The basic fracture mode in all specimens was ductile, because Al has an FCC structure and remains ductile even at low temperatures. The ductile fractures took place in a transgranular manner as could be concluded from the fractured surface features, which include voids, ridges and cavitation.

The Analysis for Relation of Fracture Toughness and Charpy Impact Energy of High Strength Pipeline Steel

2008 ◽  
Author(s):  
Guang-Li Zhang ◽  
Xin-Wei Zhao ◽  
Jin-Heng Luo ◽  
Shao-Tao Gong ◽  
Hua Zhang ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Impact Energy ◽  
Empirical Equation ◽  
Pipeline Steel ◽  
Linear Regression Analysis ◽  
Charpy Impact ◽  
High Strength ◽  
Charpy Impact Energy ◽  
Sample Data ◽  
New Equation

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.

Methodology for Estimating Thermal and Neutron Embrittlement of Cast Austenitic Stainless Steels During Service in Light Water Reactors

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
O. K. Chopra ◽  
A. S. Rao
Keyword(s):  
Fracture Toughness ◽  
Chemical Composition ◽  
Impact Energy ◽  
Reactor Core ◽  
Charpy Impact ◽  
Charpy Impact Energy ◽  
Light Water Reactors ◽  
Light Water ◽  
Thermal Embrittlement ◽  
Water Reactors

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.

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