Hydrogen-induced cracking behaviors of Incoloy alloy 825

Yong-jin Yang 1),Ke-wei Gao 1),and Chang-feng Chen 2) 1) School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China 2) Department of Materials Science and Technology,China University of Petroleum,Beijing 102249,China

摘 要：The effect of hydrogen on the fracture behaviors of Incoloy alloy 825 was investigated by means of slow strain rate testing （SSRT）.Hydrogen was introduced into the sample by electrochemical charging.The results show that surface microcracks form gradually during aging at room temperature when desorption of hydrogen takes place after hydrogen charging at a current density of 5 mA/cm 2 for 24 h.SSRT shows that the increase of ductility loss is significantly obvious as the hydrogen charging current density increases.Scanning electron microscopy （SEM） images reveal ductile fracture in the pre-charged sample with low current densities,while the fracture includes small quasi-cleavage regions and tends to be brittle fracture as the hydrogen charging current density increases to 5 mA/cm 2.

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