Spelling suggestions: "subject:"aydrogen content"" "subject:"bydrogen content""
1 |
Hydrogen in aluminium and its alloysTalbot, D. E. J. January 1989 (has links)
No description available.
|
2 |
First-principles study of the hydrogen-metal systemWang, Yan 05 1900 (has links)
No description available.
|
3 |
Effect of hydrogen on the coefficient of friction of ironGrzeskiewicz, Ronald 12 April 2010 (has links)
The friction force of an Annco iron-on-Annco iron sliding system was measured in laboratory air, nitrogen, and hydrogen. The coefficient of friction for each environment was calculated and the amplitude of the "stick-slip" behavior from each environment was observed. It was found that the coefficient of friction obtained in the hydrogen environment was significantly smaller than the values obtained in laboratory air and nitrogen. Also, the amplitude of the "stick-slip" behavior observed in a hydrogen environment was less than that obtained in laboratory air and nitrogen.
These results were attributed to a decrease in the fracture strength of the Annco iron along the interface between the pin and the disk which was caused by the presence of gaseous hydrogen. The surface energy and decohesion models for hydrogen embrittlement, both mechanisms which explain brittle behavior, were considered valid in this test. The localized plasticity model of hydrogen embrittlement was considered invalid in this test.
Copper, a noble metal not susceptible to hydrogen embrittlement, was also used in friction tests. Tests conducted with copper-on-copper sliding systems showed no statistical difference between the coefficient of friction and the amplitude of the "stick-slip" behavior as the gaseous environment was varied between laboratory air, nitrogen, and hydrogen.
Finally, recommendations for further study and testing were presented. The recommendations included changing the gaseous hydrogen pressure to both high and vacuum levels, raising the temperature of the hydrogen gas, and using anyone of the great number of iron-based alloys susceptible to hydrogen embrittlement. / Master of Science
|
4 |
Diffusion of hydrogen in molten iron.Solar, Maurice Yvan. January 1969 (has links)
No description available.
|
5 |
Diffusion of hydrogen in molten iron.Solar, Maurice Yvan. January 1969 (has links)
No description available.
|
6 |
Formation of Superhexagonal Chromium Hydride by Exposure of Chromium Thin Film to High Temperature, High Pressure Hydrogen in a Ballistic CompressorPan, Yi 01 January 1991 (has links)
The interaction of hydrogen with metals has great environmental significance in problems ranging from the catastrophic failure of materials due to hydrogen embrittlement to safe and efficient storage of hydrogen as a metal hydride. Chromium (Cr) is widely used as an alloying agent to produce materials such as stainless steel and as an electroplated coating on materials to prevent corrosion and to minimize wear. Hydrogen which co-deposits with chromium during electroplating forms hexagonal close packed CrH or face centered cubic CrH2 which cracks the deposit. The behavior of hydrogen in Cr, especially the crystal structure modifications of metal Cr when it is exposed to hot, dense hydrogen gas is not completely understood. In equilibrium study, chromium hydride has been found of hexagonal close packed structure under 400 °C with high hydrogen pressure. Experiments at higher temperatures are limited by the equipment and technology. This dissertation describes a novel, non-equilibrium method which was used to synthesize a new chromium hydride phase. Single crystal, body centered cubic Cr thin films were prepared by vacuum evaporation. These films were exposed to high temperature (close to the melting point of Cr), high pressure hydrogen gas in a ballistic compressor. This was followed by rapid cooling (>105 ˚C/s) to room temperature. Using the transmission electron microscope (TEM), second phase particles of superhexagonal structure, which has lattice constant A=4.77Å and C/A=1.84, are found in the films. This structure has a volume per Cr atom slightly larger than that of hexagonal closed packed CrH, so that the superhexagonal structure may contain more hydrogen than the hexagonal close packed CrH. The superhexagonal particles have a definite orientation relationship with the matrix: [021][subscript sh] II [OOl][subscript b] and (212)[subscript sh] II (IIO)[subscript ]b. The superhexagonal structure is quite stable in air and at room temperature, but decomposes to body centered cubic Cr when heated by the electron beam illumination in the TEM. No such particles were observed in Cr films exposed to pure argon under similar conditions in the ballistic compressor. Positive identification of hydrogen content was obtained by high-temperature vacuum extraction in a discharge tube. After vacuum extraction, hydrogen spectrum was observed, and the intensity of electron diffraction from superhexagonal structure decreased. Using an energy dispersive spectrometer with the capability of detecting elements down to atomic number six (carbon), no changes in composition of the films were found by comparing the characteristic x-ray spectra of the same film before and after exposure to hot, dense hydrogen in the ballistic compressor. This result suggests that this non-equilibrium method may be used for other metal-hydrogen systems to obtain new structural phases that are of scientific or technological interest.
|
7 |
Re-emission of hydrogen from metal surfacesChang, Jin-gor 05 1900 (has links)
No description available.
|
8 |
Hydrogen removal from steel.Paneni, Mario. January 1969 (has links)
No description available.
|
9 |
Hydrogen embrittlement of 4340 steel as a result of corrosion of porous cadmium electroplate.Rinker, John George 08 1900 (has links)
No description available.
|
10 |
Hydrogen embrittlement of cold worked plain carbon steelHsieh, Jang-Hsing 08 1900 (has links)
No description available.
|
Page generated in 0.099 seconds