An Absolute Method of X-ray Fluorescence Analysis Applied to Stainless Steels

2009 ◽  
pp. 57-57-6 ◽  
Author(s):  
Gordon E Noakes
Keyword(s):  
Stainless Steels ◽  
Fluorescence Analysis ◽  
X Ray ◽  
Absolute Method

Effect of Silicon on High Temperature Oxidation Of Stainless Steels★

CORROSION ◽  
1959 ◽  
Vol 15 (11) ◽  
pp. 73-77 ◽  
Author(s):  
JOHN F. RADAVICH
Keyword(s):  
Metal Oxide ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
Stainless Steels ◽  
Oxide Films ◽  
Fluorescence Analysis ◽  
X Ray Diffraction ◽  
Oxide Interface ◽  
Temperature Oxidation ◽  
X Ray

Abstract Growth of oxide films at 600 and 800 C on a series of 16 Cr-10 Ni-bal Fe stainless steels with silicon contents ranging from 0.17 to 3.55 percent was studied by electron microscopy, electron diffraction, X-ray diffraction and X-ray fluorescence analysis techniques. Oxide scales and sub-scales formed during oxidation at 1000 C were studied optically in cross section as well as by X-ray diffraction and fluorescence analysis. Results show that as silicon content increases oxidation resistance increases rapidly until at the high silicon level, 3.55 percent, a very thin oxide film is formed at 60u and 800 G and very little oxide scale forms at 1000 C. Mechanism of oxidation resistance imparted by silicon appears to be that it decreases the number of defects in the initial oxide films formed at the metal-oxide interface. With a lesser number of defects in the thin film, an enrichment of Cr at the metal-oxide interface and in the oxide films occurs and the rate of diffusion of iron outward to form the oxide scale is greatly retarded. 2.3.7

X-Ray Fluorescence Analysis of Alloy and Stainless Steels Using a Mercuric Iodide Detector*

1987 ◽  
Vol 31 ◽  
pp. 439-444
Author(s):  
Warren C. Kelliher ◽  
W. Gene Maddox
Keyword(s):  
Stainless Steels ◽  
Room Temperature ◽  
Fluorescence Analysis ◽  
Rapid Analysis ◽  
Portable Devices ◽  
Mercuric Iodide ◽  
X Ray ◽  
The Poor ◽  
Major Disadvantage ◽  
Temperature Detector

Energy dispersive x-ray fluorescence (XRF) spectrometry has been used extensively for some time now to do accurate and rapid analysis of a variety of samples. Most XRF Systems today use cryogenically cooled Si(Li) detectors to obtain the resolution needed for analysis of samples containing several elements. The need for the cryogenic coolant results in these XRP systems being rather large and not readily adaptable to portable devices. Detectors that require no cooling, or at least require only cooling obtainable by electrical weans, offer a definite advantage over cryogenically cooled detectors for use in portable devices. Mercuric iodide (HgI2) detectors are one type of such room-temperature detectors. The major disadvantage of any room-temperature detector has been the poor eneygy resolution associated with them.

X-Ray Fluorescence Analysis of Stainless Steels and Low Alloy Steels Using Secondary Targets and the Exact Program

1978 ◽  
Vol 22 ◽  
pp. 325-335 ◽  
Author(s):  
J. C. Harmon ◽  
G.E.A. Wyld ◽  
T. C. Yao ◽  
J. W. Otvos
Keyword(s):  
Stainless Steels ◽  
Fluorescence Analysis ◽  
Low Alloy Steels ◽  
X Rays ◽  
X Ray ◽  
Fundamental Parameters ◽  
Alloy Steels ◽  
Computer Based ◽  
Low X ◽  
Selection Of

Exact is a mini-computer based fundamental parameters program which is utilized for matrix corrections in energy-dispersive X-ray analyses. We have previously shown this technique to work well with radioactive sources. However, due to the limited selection of isotopic sources available and their inherent low X-ray flux, we have investigated the use of Fe, Sn, and Dy secondary-targets as sources of monochromatic X-rays. Results to date indicate that the secondary-targets provide X-ray radiation which has sufficient monochromaticity for our technique to remain valid.

An x-ray microprobe based upon a close-coupled focal-spot / glass capillary arrangement

1992 ◽  
Vol 50 (2) ◽  
pp. 1758-1759
Author(s):  
D. A. Carpenter ◽  
M. A. Taylor
Keyword(s):  
Imaging Techniques ◽  
Fluorescence Analysis ◽  
High Sensitivity ◽  
Specimen Preparation ◽  
X Rays ◽  
Glass Capillary ◽  
Close Coupling ◽  
X Ray ◽  
Point To Point ◽  
Beam Damage

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.

XRMF applications of a monolithic, polycapillary, focusing x-ray optic

1996 ◽  
Vol 54 ◽  
pp. 240-241
Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla
Keyword(s):  
Trace Elements ◽  
Point Source ◽  
Focal Spot ◽  
Fluorescence Analysis ◽  
X Rays ◽  
Focal Distance ◽  
Spot Diameter ◽  
X Ray ◽  
Focal Spot Diameter

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.

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