scholarly journals Interpretation of Nondestructive Magnetic Measurements on Irradiated Reactor Steel Material

2021 ◽  
Vol 11 (8) ◽  
pp. 3650
Author(s):  
Gábor Vértesy ◽  
Antal Gasparics ◽  
Ildikó Szenthe ◽  
Inge Uytdenhouwen
Keyword(s):  
Magnetic Measurements ◽  
Magnetic Measurement ◽  
Magnetic Hysteresis ◽  
Magnetic Method ◽  
Pressure Vessel Steel ◽  
Important Conclusion ◽  
Vessel Steel ◽  
Material Inhomogeneity ◽  
Local Material ◽  
Steel Material

Neutron irradiation-generated embrittlement of nuclear pressure vessel steel was inspected by a nondestructive magnetic method, called magnetic adaptive testing (MAT). This method is based on systematic measurement and evaluation of minor magnetic hysteresis loops. Result of MAT measurement was compared with the result of the traditional Charpy measurement. Good correlation was found between these parameters. One of the main findings of the present work is that the considerable part of scatter of points obtained by magnetic measurement can be attributed to local material inhomogeneity. Another important conclusion is that the embrittlement highly depends on the initial local material conditions, i.e., the initial microstructure, which are very different even within the same block of reactor steel material. By taking this into account, the magnetic descriptors obtain more precise determination of the local embrittlement than the traditionally used destructive mechanical parameters from Charpy data.

scholarly journals Inspection of Reactor Steel Degradation by Magnetic Adaptive Testing

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 963
Author(s):  
Gábor Vértesy ◽  
Antal Gasparics ◽  
Ildikó Szenthe ◽  
Ferenc Gillemot ◽  
Inge Uytdenhouwen
Keyword(s):  
Structural Changes ◽  
Magnetic Measurements ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Charpy Impact ◽  
Adaptive Testing ◽  
Pressure Vessel Steel ◽  
Vessel Steel ◽  
Type Definition ◽  
Magnetic Adaptive Testing

Degradation of nuclear pressure vessel steel materials, 15Kh2NMFA type and A508 Cl2 type (definition is given in the text) were investigated by a novel magnetic nondestructive testing method, so-called Magnetic Adaptive Testing (MAT), which is based on systematic measurement and evaluation of minor magnetic hysteresis loops. The measured samples were thermally treated by a special step cooling procedure, which generated structural changes in the material. It was found that this type of degradation can be easily followed by magnetic measurements. Charpy impact test were also performed and the results were compared with the magnetic parameters. In case of 15Kh2NMFA steel, a good, reliable and closely linear correlation was found between magnetic descriptors and transition temperature.

scholarly journals Effect of long-term thermal aging on magnetic hysteresis for low-alloy pressure vessel steel

2017 ◽  
Vol 903 ◽  
pp. 012049
Author(s):  
Satoru Kobayashi ◽  
Ferenc Gillemot ◽  
Ákos Horváth ◽  
Marta Horváth ◽  
Almásy László
Keyword(s):  
Thermal Aging ◽  
Pressure Vessel ◽  
Magnetic Hysteresis ◽  
Pressure Vessel Steel ◽  
Vessel Steel

scholarly journals Analysis of Surface Roughness Influence in Non-Destructive Magnetic Measurements Applied to Reactor Pressure Vessel Steels

2020 ◽  
Vol 10 (24) ◽  
pp. 8938
Author(s):  
Gábor Vértesy ◽  
Antal Gasparics ◽  
James M. Griffin ◽  
Jino Mathew ◽  
Michael E. Fitzpatrick ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Pressure Vessel ◽  
Magnetic Measurements ◽  
Surface Condition ◽  
Reactor Pressure Vessel ◽  
Pressure Vessel Steel ◽  
Vessel Steel ◽  
Pressure Vessel Steels ◽  
Non Destructive ◽  
Reactor Pressure

The influence of surface roughness on magnetic measurements of Reactor Pressure Vessel Steels was investigated by applying two types of magnetic, non-destructive measurement on nuclear reactor pressure vessel steel samples: magnetic adaptive testing (MAT) and magnetic Barkhausen noise measurement (MBN). The surface roughness was modified by primary and secondary machine cutting forces. Different settings of machine cutting produced different surface conditions. It was found that for both measurements a monotonic correlation was found to exist between magnetic parameters and surface roughness. Results of the MAT measurements found that the correlation depends on the speed (i.e., on the applied slew rate) of the magnetizing current. In a similar fashion, results from the MBN method show good agreement with MAT, where the response diminishes with an increase in surface roughness. The results show the importance of accounting for surface condition in the interpretation of results of non-destructive magnetic testing.

Dislocation structures in 16MND5 pressure vessel steel strained in uniaxial tension at −196°C

2005 ◽  
Vol 96 (8) ◽  
pp. 909-912
Author(s):  
Karel Obrtlík ◽  
Christian Robertson ◽  
Bernard Marini
Keyword(s):  
Uniaxial Tension ◽  
Pressure Vessel ◽  
Pressure Vessel Steel ◽  
Vessel Steel

scholarly journals Micromagnetic Characterization of Operation-Induced Damage in Charpy Specimens of RPV Steels

2021 ◽  
Vol 11 (7) ◽  
pp. 2917
Author(s):  
Madalina Rabung ◽  
Melanie Kopp ◽  
Antal Gasparics ◽  
Gábor Vértesy ◽  
Ildikó Szenthe ◽  
...  
Keyword(s):  
Neutron Irradiation ◽  
Pressure Vessel ◽  
Operating Conditions ◽  
Magnetic Characteristics ◽  
Pressure Vessel Steel ◽  
Training Procedure ◽  
Vessel Steel ◽  
Before And After ◽  
The Individual ◽  
Magnetic Adaptive Testing

The embrittlement of two types of nuclear pressure vessel steel, 15Kh2NMFA and A508 Cl.2, was studied using two different methods of magnetic nondestructive testing: micromagnetic multiparameter microstructure and stress analysis (3MA-X8) and magnetic adaptive testing (MAT). The microstructure and mechanical properties of reactor pressure vessel (RPV) materials are modified due to neutron irradiation; this material degradation can be characterized using magnetic methods. For the first time, the progressive change in material properties due to neutron irradiation was investigated on the same specimens, before and after neutron irradiation. A correlation was found between magnetic characteristics and neutron-irradiation-induced damage, regardless of the type of material or the applied measurement technique. The results of the individual micromagnetic measurements proved their suitability for characterizing the degradation of RPV steel caused by simulated operating conditions. A calibration/training procedure was applied on the merged outcome of both testing methods, producing excellent results in predicting transition temperature, yield strength, and mechanical hardness for both materials.

Multiaxial Fatigue of 16MnR Steel

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
Zengliang Gao ◽  
Tianwen Zhao ◽  
Xiaogui Wang ◽  
Yanyao Jiang
Keyword(s):  
Pure Shear ◽  
Ambient Air ◽  
Shear Loading ◽  
Multiaxial Fatigue ◽  
Experimental Results ◽  
Pressure Vessel Steel ◽  
Critical Plane ◽  
Cracking Behavior ◽  
Vessel Steel ◽  
Axial Torsion

Uniaxial, torsion, and axial-torsion fatigue experiments were conducted on a pressure vessel steel, 16MnR, in ambient air. The uniaxial experiments were conducted using solid cylindrical specimens. Axial-torsion experiments employed thin-walled tubular specimens subjected to proportional and nonproportional loading. The true fracture stress and strain were obtained by testing solid shafts under monotonic torsion. Experimental results reveal that the material under investigation does not display significant nonproportional hardening. The material was found to display shear cracking under pure shear loading but tensile cracking under tension-compression loading. Two critical plane multiaxial fatigue criteria, namely, the Fatemi–Socie criterion and the Jiang criterion, were evaluated based on the experimental results. The Fatemi–Socie criterion combines the maximum shear strain amplitude with a consideration of the normal stress on the critical plane. The Jiang criterion makes use of the plastic strain energy on a material plane as the major contributor to the fatigue damage. Both criteria were found to correlate well with the experiments in terms of fatigue life. The predicted cracking directions by the criteria were less satisfactory when comparing with the experimentally observed cracking behavior under different loading conditions.

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