Mitigation of hydrogen embrittlement in alloy custom age 625 PLUS® via grain boundary engineering

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:818

Article

DeMott, Ryan W.¹  Kernion, Samuel²  Leff, Asher C.¹  Taheri, Mitra L.^1,3 

[1] Drexel Univ, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA

[2] Carpenter Technol Corp, Reading, PA USA

[3] Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA

关键词: Grain boundary engineering;    Hydrogen embrittlement;    Nickel superalloys;    Geometrically necessary dislocations;    Thermomechanical processing;    Twin related domains;   

DOI  :  10.1016/j.msea.2021.141377

来源: Elsevier

【 摘 要 】

Hydrogen embrittlement is the deterioration of mechanical properties in a metal exposed to hydrogen, often characterized by brittle, intergranular fracture at low applied stresses. While grain boundary engineering has been applied to mitigate this issue, ambiguity in the mechanisms behind hydrogen embrittlement leads to ambiguity in the mechanism by which grain boundary engineering helps to mitigate this problem. In this study, grain boundary engineering was applied to improve resistance to hydrogen embrittlement in Custom Age 625 PLUS (R), an alloy frequently used in corrosive environments where hydrogen embrittlement is of particular concern. Iterative low strain cold rolling followed by annealing at intermediate temperature successfully produced a grain boundary engineered microstructure with large twin-related domains and a high fraction of interconnected coincident site lattice (CSL) boundaries. Rising step load testing demonstrated that grain boundary engineering increased the stress intensity at which failure from hydrogen embrittlement occurred and caused a shift from intergranular to transgranular crack propagation. Evidence of localized plasticity on fracture surfaces suggest that hydrogen-enhanced localized plasticity (HELP) is the dominant mechanism of hydrogen embrittlement.

【 授权许可】

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