Hydrogen enhanced decohesion mechanism
Web1 HEDE-Hydrogen Enhanced DEcohesion mechanism 该机制的基本思想是，因为H原子的存在，在裂纹尖端会形成Hydride，降低了原来的原子键的键能，使得在外载荷的作用 … WebMore than ninety years ago hydrogen-enhanced decohesion was proposed by Pfeil in his 1926 paper [1] regarding tensile tests during ‘pickling’ of ferritic steels. He observed intergranular and transgranular failures, and he suggested they were caused by a reduction in strength of metal–metal bonds. He did not offer an explanation for the ...
Hydrogen enhanced decohesion mechanism
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Web1 jan. 2011 · Mechanisms of hydrogen embrittlement in steels and other materials are described, and the evidence supporting various hypotheses, such as those based on hydride-formation, hydrogen-enhanced decohesion, hydrogen-enhanced localised plasticity, adsorption-induced dislocation- emission, and hydrogen-vacancy interactions, … WebThe observations are discussed on the basis of the hydrogen-enhanced decohesion and hydrogen-enhanced localized plasticity ... Bearing in mind multiple effects of hydrogen in certain metals, the specific …
WebDecohesion. The decohesion theory of Oriani and Josephic supposes that the cohesive force between atoms in the metal lattice is reduced in proportion to the hydrogen … WebThe hydrogen-enhanced local plasticity mechanism, manifested by fracture along the grain boundary, dominates the tensile process in fatigue-damaged hydrogen-filled …
Web21 uur geleden · There are a number of proposed mechanisms by which hydrogen embrittles a material, which have varying degrees of experimental support. Researchers … Web13 apr. 2024 · This indicates that crack formation along the PAGBs in T550 occurred without the help of plasticity evolution, namely hydrogen-enhanced decohesion (HEDE). [ 24 , 25 ] Furthermore, because the FCG path in T550 was mainly PAGB [Figure 2 (d)], the majority of HAFCG was predominately controlled by HEDE.
WebFig.5 Schematic diagrams of HE mechanisms. a HIPT : hydrogen-induced phase transformation theory; b HEDE : hydrogen-enhanced decohesion mechanism; c HELP : hydrogen-enhanced localized plasticity mechanism; d NVC : nanovoid coalescence mechanism; e HEDE + HELP : combined effect of hydrogen-enhanced decohesion …
WebThe microstructure associated with the hydrogen-induced features flat and quasi-cleavage on the fracture surface of a lath martensitic steel has been visualized in a transmission electron microscope by using focused-ion beam machining to extract samples perpendicular to the fracture surface. Beneath both hydrogen-induced fracture surfaces there ... it project gantt chartWeb13 apr. 2024 · So far, a large number of studies on hydrogen embrittlement of steels have been reported, in which some failure mechanisms, such as the HELP model (hydrogen-enhanced localized plasticity) [23], [24], [25] and the HEDE mechanism (hydrogen enhanced decohesion) [26], [27] were proposed and successfully used to explain the … nelson vacation homesWeb2 jun. 2024 · The two mechanisms tested in this study were hydrogen enhanced decohesion (HEDE) and hydrogen enhanced localized plasticity (HELP). The HEDE model explains increased crack growth as resulting … it project executive summary templateWeb13 apr. 2024 · The H-enhanced local plasticity mechanism was firstly suggested by Beachem in 1971, based on the fracture surface analysis as a function of stress intensity … it project for final yearWeb12 nov. 2024 · In the study of hydrogen changing the fracture morphology, it was found that: the change of hydrogen embrittlement fracture mode of HR specimen is dominated … it project for final year studentsWeb13 apr. 2024 · This indicates that crack formation along the PAGBs in T550 occurred without the help of plasticity evolution, namely hydrogen-enhanced decohesion (HEDE). [ 24 , … it project initiation formWeb11 apr. 2024 · Industrial-grade pure nickel, NI-201, was tensile tested in high-pressure hydrogen gas at various testing temperatures and strain rates. The degree of… nelson vce psychology 2023