Thermoelectric Power: A Nondestructive Method for Monitoring Irradiation Effects in Ferritic Steels

2008 ◽  
pp. 1029-1029-14 ◽  
Author(s):  
S Miloudi ◽  
S Jumel ◽  
P Pareige ◽  
J-F Coste ◽  
J-C Van Duysen
Keyword(s):  
Thermoelectric Power ◽  
Nondestructive Method ◽  
Ferritic Steels ◽  
Irradiation Effects

Helium Ion Irradiation Effects in ODS and Non-ODS Ferritic Steels

2011 ◽  
pp. 300-305 ◽  
Author(s):  
Ryuta Kasada ◽  
Hiromasa Takahashi ◽  
Kentaro Yutani ◽  
Hirotatsu Kishimoto ◽  
Akihiko Kimura
Keyword(s):  
Ion Irradiation ◽  
Ferritic Steels ◽  
Irradiation Effects ◽  
Helium Ion

Assessment of Fracture Toughness Models for Ferritic Steels Used in Section XI of the ASME Code Relative to Current Data-Based Models

2014 ◽  
Author(s):  
Mark Kirk ◽  
Marjorie Erickson ◽  
William Server ◽  
Gary Stevens ◽  
Russell Cipolla
Keyword(s):  
Fracture Toughness ◽  
Current Data ◽  
Ferritic Steels ◽  
Irradiation Effects ◽  
Irradiation Embrittlement ◽  
New Information ◽  
Pressurized Thermal Shock ◽  
Asme Code ◽  
The Mean ◽  
The U.S

Section XI of the ASME Code provides models of the fracture toughness of ferritic steel. Recent efforts have been made to incorporate new information, such as the Code Cases that use the Master Curve, but the fracture toughness models in Section XI have, for the most part, remained unchanged since the KIc and KIa curves were first developed in Welding Research Council Bulletin 175 in 1972. Since 1972, considerable advancements to the state of knowledge, both theoretical and practical have occurred, particularly with regard to the amount of available data. For example, as part of the U.S. Nuclear Regulatory Commission’s (NRC’s) pressurized thermal shock (PTS) re-evaluation efforts the NRC and the industry jointly developed an integrated model that predicts the mean trends and scatter of the fracture toughness of ferritic steels throughout the temperature range from the lower shelf to the upper shelf. This collection of models was used by the NRC to establish the index temperature screening limits adopted in the Alternate PTS Rule documented in Title 10 to the U.S. Code of Federal Regulations (CFR), Part 50.61a (10CFR50.61a). In this paper the predictions of the toughness models used by the ASME Code are compared with these newer models (that are based on considerably more data) to identify areas where the ASME Code could be improved. Such improvements include the following: • On the lower shelf, the low-temperature asymptote of the KIc curve does not represent a lower bound to all available data. • On the upper shelf, the de facto KIc limit of applicability of 220 MPa√m exceeds available data, especially after consideration of irradiation effects. • The separation between the KIc and KIa curves depends on the amount of irradiation embrittlement, a functionality not captured by the ASME Section XI equations. • The temperature above which upper shelf behavior can be expected depends on the amount of irradiation embrittlement, a functionality not captured in the ASME Section XI equations.

Irradiation effects in ferritic steels

1985 ◽  
Vol 133-134 ◽  
pp. 149-155 ◽  
Author(s):  
Thomas Lechtenberg
Keyword(s):  
Ferritic Steels ◽  
Irradiation Effects

Role of Manganese and Chromium on the Segregation Kinetics of Carbon and Nitrogen to the Dislocations in Ferritic Steels

2007 ◽  
Vol 539-543 ◽  
pp. 4303-4308
Author(s):  
Véronique Massardier-Jourdan ◽  
David Colas ◽  
Jacques Merlin
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Cold Rolling ◽  
Thermoelectric Power ◽  
Ferritic Steels ◽  
Carbon And Nitrogen ◽  
The Mean ◽  
Mean Time ◽  
Kinetics Of

The thermoelectric power (or TEP) technique was used to determine the segregation kinetics of the interstitial atoms (C or N) to the dislocations in various extra-mild steels submitted to a heavy deformation by cold-rolling when substitutional atoms (Mn or Cr) are simultaneously in solid solution. It was shown that the substitutional atoms (Mn or Cr) have almost no influence on the segregation kinetics of carbon and on the activation energy associated with the segregation of this element. In contrast, these elements tend to delay the segregation kinetics of nitrogen to the dislocations all the more so as their content in solution is high. In the mean time, the activation energy associated with the segregation of nitrogen is increased.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

Microanalysis of precipitates in a ferritic steel

1978 ◽  
Vol 36 (1) ◽  
pp. 618-619
Author(s):  
J.M. Titchmarsh
Keyword(s):  
Ferritic Steel ◽  
Particle Identification ◽  
Energy Dispersive ◽  
Objective Lens ◽  
Ferritic Steels ◽  
Replica Technique ◽  
X Ray ◽  
Large Numbers ◽  
Scanning Transmission ◽  
Made In

The advances in recent years in the microanalytical capabilities of conventional TEM's fitted with probe forming lenses allow much more detailed investigations to be made of the microstructures of complex alloys, such as ferritic steels, than have been possible previously. In particular, the identification of individual precipitate particles with dimensions of a few tens of nanometers in alloys containing high densities of several chemically and crystallographically different precipitate types is feasible. The aim of the investigation described in this paper was to establish a method which allowed individual particle identification to be made in a few seconds so that large numbers of particles could be examined in a few hours.A Philips EM400 microscope, fitted with the scanning transmission (STEM) objective lens pole-pieces and an EDAX energy dispersive X-ray analyser, was used at 120 kV with a thermal W hairpin filament. The precipitates examined were extracted using a standard C replica technique from specimens of a 2¼Cr-lMo ferritic steel in a quenched and tempered condition.

In situ TEM studies of irradiation effects for materials improvement

1991 ◽  
Vol 49 ◽  
pp. 452-453
Author(s):  
Charles W. Allen
Keyword(s):  
Nuclear Reactor ◽  
Austenitic Stainless Steels ◽  
High Energy ◽  
Point Of View ◽  
In Situ Tem ◽  
Irradiation Effects ◽  
Tem Analysis ◽  
Radiation Induced ◽  
Analytical Tools

Irradiation effects studies employing TEMs as analytical tools have been conducted for almost as many years as materials people have done TEM, motivated largely by materials needs for nuclear reactor development. Such studies have focussed on the behavior both of nuclear fuels and of materials for other reactor components which are subjected to radiation-induced degradation. Especially in the 1950s and 60s, post-irradiation TEM analysis may have been coupled to in situ (in reactor or in pile) experiments (e.g., irradiation-induced creep experiments of austenitic stainless steels). Although necessary from a technological point of view, such experiments are difficult to instrument (measure strain dynamically, e.g.) and control (temperature, e.g.) and require months or even years to perform in a nuclear reactor or in a spallation neutron source. Consequently, methods were sought for simulation of neutroninduced radiation damage of materials, the simulations employing other forms of radiation; in the case of metals and alloys, high energy electrons and high energy ions.

Defects in Crystals

1968 ◽  
Vol 26 ◽  
pp. 244-245
Author(s):  
Kenneth R. Lawless
Keyword(s):  
Electron Microscope ◽  
Point Defects ◽  
Surface Defects ◽  
Chemical Properties ◽  
Material Point ◽  
Crystal Defects ◽  
Defects In Crystals ◽  
Irradiation Effects ◽  
Normal Lattice ◽  
Line Defects

One of the most important applications of the electron microscope in recent years has been to the observation of defects in crystals. Replica techniques have been widely utilized for many years for the observation of surface defects, but more recently the most striking use of the electron microscope has been for the direct observation of internal defects in crystals, utilizing the transmission of electrons through thin samples.Defects in crystals may be classified basically as point defects, line defects, and planar defects, all of which play an important role in determining the physical or chemical properties of a material. Point defects are of two types, either vacancies where individual atoms are missing from lattice sites, or interstitials where an atom is situated in between normal lattice sites. The so-called point defects most commonly observed are actually aggregates of either vacancies or interstitials. Details of crystal defects of this type are considered in the special session on “Irradiation Effects in Materials” and will not be considered in detail in this session.

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