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忠一, 大西; 龍郎, 原; 好孝, 毛利; 義三, 中谷

doi:10.2464/jilm.27.473

Cited by 10 publications

(3 citation statements)

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“…1215) In the 5000 series alloy, hydrogen embrittlement (HE) associated with intergranular cracking was confirmed in an Al8%Mg alloy in which hydrogen was introduced by the cathodic charging method with no apparent corrosion. 16) Humid environment as a source of hydrogen may also be playing an important role in the initiation and propagation of SCC in 5000 series alloys. 17,18) Water vapor in air can be a source of hydrogen for hydrogen embrittlement (HE) through reactions such as indicated in eq.…”

Section: Introductionmentioning

confidence: 99%

Humid Gas Stress Corrosion Cracking in MIG-Welded 5083 Aluminum Alloy Plate

et al. 2020

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In 5000 series (AlMg) alloys, hydrogen embrittlement (HE) becomes a concern when Mg content exceeds 5%. The local Mg content will become higher than 5% due to solidification segregation in the weld joint of 5083 alloy. In this study, resistance to HE of MIG-welded 5083 aluminum alloy at three areas (weld center, weld corner and HAZ) was investigated by newly developed humid gas stress corrosion cracking (HG-SCC) test. Slow strain rate tensile (SSRT) test on base metal and welded joint was also conducted for comparison.It was newly revealed that HG-SCC crack extends only in the sample of weld corner, confirming HE in this area. For the other areas, HG-SCC crack did not propagate, confirming HE resistance of these areas. From the results of SSRT test, neither the base nor welding material showed reduction in strength or ductility. Therefore, it was concluded that HE in 5083 MIG welds is only detectable by HG-SCC test. The reason for this should be in the fact that HG-SCC test can specifically test different local areas, while the softest area (weld center) always deforms preferentially and fractures in SSRT test.

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Section: Introductionmentioning

confidence: 99%

Humid Gas Stress Corrosion Cracking in MIG-Welded 5083 Aluminum Alloy Plate

et al. 2020

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“…[1][2][3][4][5][6][7][8] Furthermore, with the recent commercialization of fuel cells, it has become important to determine the effects of a high amount of absorbed hydrogen on the properties of aluminum because the chances of such materials being utilized in a hydrogen atmosphere are on the increase. Ohnishi 9) and Itoh and Kanno 10) summarized the existing states of hydrogen in aluminum; for example those are trapped to crystallographic imperfections like the interface of second phase, defects such as dislocations, solid solutions, or gaseous states within cavities.…”

Section: Introductionmentioning

confidence: 99%

Existing State of Hydrogen in Electrochemically Charged Commercial-Purity Aluminum and Its Effects on Tensile Properties

et al. 2011

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Hydrogen was introduced in commercial-purity (99%) aluminum by electrochemical charging to study the existing state of hydrogen and its effects on the mechanical properties of aluminum. Electrochemical charging was conducted in an aqueous H 2 SO 4 solution with 0.1% NH 4 SCN as a hydrogen recombination poison. The potential and pH during the charging were determined from the immune, passive, and corrosive regions in the Pourbaix diagram to determine the optimum conditions for the charging. The maximum amount of hydrogen absorbed was obtained in the immune region. The amount of hydrogen and its existing state were examined using hydrogen desorption curves, which were obtained by thermal desorption spectroscopy. The curves showed distinctive peaks corresponding to trapping sites of hydrogen in the material. One of the peaks was observed at approximately 100 C, and it corresponds to vacancies and dislocations in the material; another peak was observed at approximately 400 C and it corresponds to molecular hydrogen in blisters. It was presumed that charged hydrogen diffuses into the bulk of the material to form hydrogen-vacancy pairs, and then these pairs cluster to form blisters. The fracture strain of charged aluminum in the immune region decreased with decreasing strain rate, showing an inverse dependence on the fracture strain of the uncharged material. This phenomenon was considered to be caused by hydrogen transport by dislocations through the interaction between hydrogen and dislocations. The phenomenon was further confirmed by the observation of hydrogen release during tensile deformation, where the amount of hydrogen was high in the strain rate range where the interaction between dislocations and hydrogen was prominent.

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“…Many research studies [1][2][3][4][5] have been carried out to clarify the role of hydrogen in material degradation of aluminum alloys since hydrogen embrittlement was suggested as one of the dominant mechanisms of their stress corrosion cracking. However, it has not been easy to evaluate the effect of hydrogen on mechanical properties of aluminum alloys in comparison with steels because of their stable and protective oxide films, which act as a strong barrier for hydrogen penetration.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Susceptibility to Hydrogen Embrittlement of 7075 Aluminum Alloy by Hydrogen Addition Using Flax-Treatment Method

et al. 2006

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It is more difficult with aluminum alloys to investigate the effect of hydrogen on their mechanical properties than with steels because of their stable and protective oxide films, which act as a strong barrier for hydrogen penetration. In this study, after the flux-treatment, 7075-T6 alloy was subjected to thermal desorption spectroscopic (TDS) analysis and tensile test using the slow strain rate technique (SSRT) to establish a procedure for adding hydrogen to aluminum alloys and clarify the influence of hydrogen on their environmental embrittlement. The fluxtreatment consisted of applying a flux-solution for soldering on specimen surfaces and vaporizing water of the solution. These flux-treated specimens were exposed in a desiccator for various periods of time and then the solidified-flux and corrosion products were removed from the specimen surfaces before the TDS analysis and the tensile test. The experimental results revealed that hydrogen was absorbed into the alloy by the flux-treatment and the hydrogen content had a tendency to increase with increasing exposure time. Additionally, the fracture strain of tensile specimen decreased with exposure time, resulting in more severe embrittlement. Consequently, this flux-treatment method was considered to be an appropriate procedure for adding hydrogen to aluminum alloys and for evaluating their susceptibility to hydrogen embrittlement when combined with SSRT.

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Abstract: Hydrogen charging and room temperature aging were carried out on the Al-8%Mg alloy aged at 170•Ž for 24 hr.

Cited by 10 publications

References 0 publications

Humid Gas Stress Corrosion Cracking in MIG-Welded 5083 Aluminum Alloy Plate

Humid Gas Stress Corrosion Cracking in MIG-Welded 5083 Aluminum Alloy Plate

Existing State of Hydrogen in Electrochemically Charged Commercial-Purity Aluminum and Its Effects on Tensile Properties

Evaluation of Susceptibility to Hydrogen Embrittlement of 7075 Aluminum Alloy by Hydrogen Addition Using Flax-Treatment Method

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