Investigation of the Local Austenite Stability Related to Hydrogen Environment Embrittlement of Austenitic Stainless Steels
Autor: | Werner Theisen, Gero Egels, Robert Fussik, Sebastian Weber |
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Rok vydání: | 2018 |
Předmět: |
010302 applied physics
Austenite Materials science Hydrogen Phase stability Mechanical Engineering Metallurgy chemistry.chemical_element 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences chemistry Mechanics of Materials 0103 physical sciences engineering General Materials Science Austenitic stainless steel 0210 nano-technology Embrittlement Hydrogen embrittlement |
Zdroj: | Materials Science Forum. 941:263-268 |
ISSN: | 1662-9752 |
Popis: | Hydrogen is increasingly considered as fuel for future mobility or for stationary applications. However, the safe distribution and storage of pure hydrogen is only possible with suitable materials. Interstitially dissolved hydrogen atoms in the lattice of numerous metals are responsible for hydrogen embrittlement (HE). If hydrogen is introduced by an external source, it is called hydrogen environment embrittlement (HEE). Commonly, steels like AISI 316L with a high resistance to HEE include a large number of alloying elements and in high amount. High alloying levels result in a decrease of cost-efficiency. Therefore, the systematic investigation of lean-alloyed austenitic stainless steels is necessary in order to understand the mechanism of HEE. For that purpose, the steel grades AISI 304L and AISI 316L are selected in this work. Tensile tests in air and 400 bar hydrogen gas atmospheres are performed. After tensile testing in H, AISI 304L revealed secondary cracks at the specimen surface, which are related to the local austenite stability, which in turn is affected by the level of micro-segregation. The microstructural investigations of the crack environment directly contribute to the understanding of the micro-mechanisms of HEE. Property-maps generated from experimentally measured distributions of alloying elements allow to correlate the impact of micro-segregations on the local austenite stability. It is shown, that local segregation-bands affect the initiation and propagation of secondary cracks. In this context, the local austenite stability which is significantly affected by the Ni distribution will be discussed in detail by comparison of the metastable austenitic steel grades AISI 304L and AISI 316L. |
Databáze: | OpenAIRE |
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