The Analysis of Fracture Mechanisms of Ferritic Steel 13HMF at Low Temperatures

2010 ◽  
Vol 7 (5) ◽  
pp. 102470 ◽  
Author(s):  
A. Neimitz ◽  
J. Galkiewicz ◽  
S. Kalluri ◽  
R. M. McGaw ◽  
A. Neimitz ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Ferritic Steel ◽  
Fracture Mechanisms

Irradiation hardening and ductility loss of a low-activation 9Cr-1V ferritic steel at low temperatures

1989 ◽  
Vol 166 (3) ◽  
pp. 265-277 ◽  
Author(s):  
F. Abe ◽  
T. Noda ◽  
H. Araki ◽  
M. Narui ◽  
H. Kayano
Keyword(s):  
Low Temperatures ◽  
Ferritic Steel ◽  
Irradiation Hardening ◽  
Ductility Loss

scholarly journals Effect of Temperature and Moisture on the Tensile Properties of a TEPs-Modified Adhesive

2018 ◽  
Vol 55 (4) ◽  
pp. 478-481 ◽  
Author(s):  
Mariana D. Banea ◽  
Lucas F.m. Da Silva ◽  
Ricardo Carbas ◽  
Silvio De Barros
Keyword(s):  
Low Temperatures ◽  
Joint Strength ◽  
Sem Analysis ◽  
Effect Of Temperature ◽  
Fracture Mechanisms ◽  
Moisture Uptake ◽  
Tensile Data ◽  
Main Factors ◽  
Water Saturated ◽  
Strength Of Adhesive Joints

The main factors that affect the strength of adhesive joints are the exposure to moist environments and high and/or low temperatures. The objective of this paper is to measure the water diffusion in adhesives modified with thermally expandable particles (TEPs) and assess the joint strength of water saturated modified adhesives. Bulk specimens were used to measure the diffusion coefficient of water in a TEPs-modified adhesive. The tensile data as a function of TEPs content, moisture uptake and temperature was measured. It was found that the presence of moisture and the temperature affect the mechanical properties of TEPs-modified adhesive. Further, a scanning electron microscope (SEM) analysis was performed in order to examine the fracture surfaces of the tensile specimens tested as a function of temperature and water uptake. SEM analysis showed that the absorbed moisture and temperature change the fracture mechanisms and the morphology of the specimens.

Fracture-mechanisms in pure iron, two austenitic steels, and one ferritic steel

1980 ◽  
Vol 11 (2) ◽  
pp. 333-347 ◽  
Author(s):  
R. J. Fields ◽  
T. Weerasooriya ◽  
M. F. Ashby
Keyword(s):  
Pure Iron ◽  
Ferritic Steel ◽  
Austenitic Steels ◽  
Fracture Mechanisms

scholarly journals Fracture Mechanisms of S355 Steel—Experimental Research, FEM Simulation and SEM Observation

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3959 ◽  
Author(s):  
Ihor Dzioba ◽  
Sebastian Lipiec
Keyword(s):  
Experimental Research ◽  
Ferritic Steel ◽  
Fem Simulation ◽  
Local Area ◽  
True Stress ◽  
Fracture Mechanisms ◽  
The Finite Element Method ◽  
Characteristic Values ◽  
Cracking Process ◽  
Made In

In this study, the fracture mechanisms of S355 ferritic steel were analyzed. In order to obtain different mechanisms of fracture (completely brittle, mixed brittle and ductile or completely ductile), tests were carried out over a temperature range of −120 to +20 °C. Our experimental research was supplemented with scanning electron microscopy (SEM) observations of the specimens’ fracture surfaces. Modeling and load simulations of specimens were performed using the finite element method (FEM) in the ABAQUS program, and accurate calibration of the true stress–strain material dependence was made. In addition, the development of mechanical fields before the crack tip of the cracking process in the steel was analyzed. The distributions of stresses and strains in the local area before the crack front were determined for specimens fractured according to different mechanisms. Finally, the conditions and characteristic values of stresses and strains which caused different mechanisms of fracture—fully brittle, mixed brittle and ductile or fully ductile—were determined.

Interpretation of irradiation-induced changes in electron diffractograms and images of extinction contours at low temperatures

1984 ◽  
Vol 42 ◽  
pp. 268-269
Author(s):  
E. Knapek ◽  
H. Formanek ◽  
G. Lefranc ◽  
I. Dietrich
Keyword(s):  
Low Temperatures ◽  
Carbon Films ◽  
Organic Crystals ◽  
Wide Spread ◽  
Lens System ◽  
Preparation Conditions ◽  
Thin Carbon ◽  
Electron Diffractograms ◽  
Diffraction Patterns ◽  
Induced Changes

A few years ago results on cryoprotection of L-valine were reported, where the values of the critical fluence De i.e, the electron exposure which decreases the intensity of the diffraction reflections by a factor e, amounted to the order of 2000 + 1000 e/nm2. In the meantime a discrepancy arose, since several groups published De values between 100 e/nm2 and 1200 e/nm2 /1 - 4/. This disagreement and particularly the wide spread of the results induced us to investigate more thoroughly the behaviour of organic crystals at very low temperatures during electron irradiation.For this purpose large L-valine crystals with homogenuous thickness were deposited on holey carbon films, thin carbon films or Au-coated holey carbon films. These specimens were cooled down to nearly liquid helium temperature in an electron microscope with a superconducting lens system and irradiated with 200 keU-electrons. The progress of radiation damage under different preparation conditions has been observed with series of electron diffraction patterns and direct images of extinction contours.

Radiation Damage of Support Films

1981 ◽  
Vol 39 ◽  
pp. 28-29
Author(s):  
H.A. Cohen ◽  
W. Chiu
Keyword(s):  
Transfer Function ◽  
Low Temperatures ◽  
Carbon Support ◽  
Contrast Transfer Function ◽  
Electron Dose ◽  
Imaging Parameters ◽  
Negative Stain ◽  
Phase Corrections ◽  
Two Parameters ◽  
Medium Dose

The goal of imaging the finest detail possible in biological specimens leads to contradictory requirements for the choice of an electron dose. The dose should be as low as possible to minimize object damage, yet as high as possible to optimize image statistics. For specimens that are protected by low temperatures or for which the low resolution associated with negative stain is acceptable, the first condition may be partially relaxed, allowing the use of (for example) 6 to 10 e/Å2. However, this medium dose is marginal for obtaining the contrast transfer function (CTF) of the microscope, which is necessary to allow phase corrections to the image. We have explored two parameters that affect the CTF under medium dose conditions.Figure 1 displays the CTF for carbon (C, row 1) and triafol plus carbon (T+C, row 2). For any column, the images to which the CTF correspond were from a carbon covered hole (C) and the adjacent triafol plus carbon support film (T+C), both recorded on the same micrograph; therefore the imaging parameters of defocus, illumination angle, and electron statistics were identical.

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 Tensile Experiments at Low Temperatures on Niobium Single Crystals by H.V.E.M.

1975 ◽  
Vol 33 ◽  
pp. 58-59
Author(s):  
F. H. Louchet ◽  
L. P. Kubin
Keyword(s):  
Electron Microscope ◽  
Transition Temperature ◽  
Low Temperature ◽  
Slip System ◽  
Low Temperatures ◽  
Tensile Axis ◽  
Image Intensifier ◽  
Screw Dislocations ◽  
Source Operation

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].Our results concern:- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.

Ultrastructure of the soil fungus, Geomyces pannorus

1984 ◽  
Vol 42 ◽  
pp. 738-739
Author(s):  
J. A. Traquair ◽  
E. G. Kokko
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fine Structure ◽  
Low Temperatures ◽  
Soil Fungus ◽  
Organic Soils ◽  
Anatomical Studies ◽  
Transmission Electron ◽  
Electron Microscopical ◽  
Scanning Electron

With the advent of improved dehydration techniques, scanning electron microscopy has become routine in anatomical studies of fungi. Fine structure of hyphae and spore surfaces has been illustrated for many hyphomycetes, and yet, the ultrastructure of the ubiquitous soil fungus, Geomyces pannorus (Link) Sigler & Carmichael has been neglected. This presentation shows that scanning and transmission electron microscopical data must be correlated in resolving septal structure and conidial release in G. pannorus.Although it is reported to be cellulolytic but not keratinolytic, G. pannorus is found on human skin, animals, birds, mushrooms, dung, roots, and frozen meat in addition to various organic soils. In fact, it readily adapts to growth at low temperatures.

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