【Q&A Question 239】2018.09.02
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【Q&A Question 239】September 02, 2018: Briefly describe the different types of hydrogen-induced damage to equipment and pipelines under high-temperature and high-pressure hydrogen conditions It is divided into five types: hydrogen bubbling, hydrogen embrittlement, surface decarburization, hydrogen corrosion, and hydrogen exfoliation. Hydrogen bubbling: Hydrogen atoms penetrate into the steel, where they aggregate at the sites of dislocations or defects to form hydrogen molecules. The resulting volume expansion creates high hydrogen pressure in those areas, causing bubbles to form in the steel. Hydrogen embrittlement: When steel is used in hydrogen-rich environments, hydrogen diffuses into the crystal lattice in atomic form, while also accumulating in the form of molecules around grain boundaries or non-metallic inclusions. As a result, although there are no particularly noticeable changes in tensile strength or hardness, the notch strength or toughness decreases significantly at room temperature, and cracks may sometimes occur. Materials affected by hydrogen embrittlement can have their ductility and toughness restored after dehydrogenation, provided no cracks occur. Surface decarburization: Surface decarburization can occur when steel comes into contact with hydrogen. Surface decarburization does not cause cracks, but the strength and hardness of the material decrease slightly, while the elongation increases. Hydrogen corrosion: At high temperatures (above 220°C) and high pressures, hydrogen reacts chemically with impurities in the alloy (carbides or dissolved carbon) or alloying elements (such as silicon) to produce high-pressure gases. This leads to decarburization of the steel and crack formation at the crystal grain boundaries. The tensile strength, ductility, and toughness of materials subjected to hydrogen corrosion are significantly reduced. Hydrogen exfoliation: Hydrogen diffuses into the steel under high temperature and pressure. During equipment maintenance or cooling, when the temperature drops below 150°C, hydrogen cannot be released in time, and a certain amount of hydrogen remains trapped in the steel. Under specific conditions, this can lead to cracking between the surfacing layer and the base material. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) Correct: 3 wealth, Incorrect: 1 wealth ； Mass posting of posts – rated based on the lowest score ； Replies that are unrelated to the answer are considered spam and will be deleted immediately. For management purposes, if you need to view content from a few days ago, please go to https://bbs.hcbbs.com/home.php?mod=space&uid=3862647&do=thread&view=me&from=space through the summary post below
Hydrogen embrittlement and hydrogen-induced delamination of reactor cladding layers. These can be avoided through isothermal dehydrogenation.
1 Hydrogen corrosion leads to hydrogen-induced cracking. 2 High-pressure, high-temperature hydrogen penetrates into the metal structure; rapid cooling can result in hydrogen embrittlement. 3 Methanation reactions cause a decline in the material’s properties
It is divided into five types: hydrogen bubbling, hydrogen embrittlement, surface decarburization, hydrogen corrosion, and hydrogen exfoliation. Hydrogen bubbling: Hydrogen atoms penetrate into the steel, where they aggregate at the sites of dislocations or defects to form hydrogen molecules. The resulting volume expansion creates high hydrogen pressure in those areas, causing bubbles to form in the steel. Hydrogen embrittlement: When steel is used in hydrogen-rich environments, hydrogen diffuses into the crystal lattice in atomic form, while also accumulating in the form of molecules around grain boundaries or non-metallic inclusions. As a result, although there are no particularly noticeable changes in tensile strength or hardness, the notch strength or toughness decreases significantly at room temperature, and cracks may sometimes occur. Materials affected by hydrogen embrittlement can have their ductility and toughness restored after dehydrogenation, provided no cracks occur. Surface decarburization: Surface decarburization can occur when steel comes into contact with hydrogen. Surface decarburization does not cause cracks, but the strength and hardness of the material decrease slightly, while the elongation increases. Hydrogen corrosion: At high temperatures (above 220°C) and high pressures, hydrogen reacts chemically with impurities in the alloy (carbides or dissolved carbon) or alloying elements (such as silicon) to produce high-pressure gases. This leads to decarburization of the steel and crack formation at the crystal grain boundaries. The tensile strength, ductility, and toughness of materials subjected to hydrogen corrosion are significantly reduced. Hydrogen exfoliation: Hydrogen diffuses into the steel under high temperature and pressure. During equipment maintenance or cooling, when the temperature drops below 150°C, hydrogen cannot be released in time, and a certain amount of hydrogen remains trapped in the steel; under specific conditions, this can lead to cracking between the surfacing layer and the base material
It is divided into five types: hydrogen bubbling, hydrogen embrittlement, surface decarburization, hydrogen corrosion, and hydrogen exfoliation.
It is divided into five types: hydrogen bubbling, hydrogen embrittlement, surface decarburization, hydrogen corrosion, and hydrogen exfoliation.
Hydrogen bubbling, hydrogen embrittlement, surface decarburization, hydrogen corrosion, hydrogen exfoliation
It is divided into five types: hydrogen bubbling, hydrogen embrittlement, surface decarburization, hydrogen corrosion, and hydrogen exfoliation.
It is divided into five types: hydrogen bubbling, hydrogen embrittlement, surface decarburization, hydrogen corrosion, and hydrogen exfoliation. Hydrogen bubbling: Hydrogen atoms penetrate into the steel, where they aggregate at the dislocations or defect sites to form hydrogen molecules. The resulting volume expansion creates high hydrogen pressure in those areas, causing bubbles to form in the steel. Hydrogen embrittlement: When steel is used in hydrogen-rich environments, hydrogen diffuses into the crystal lattice in atomic form, while also accumulating in the form of molecules around grain boundaries or non-metallic inclusions. As a result, although there are no particularly noticeable changes in tensile strength or hardness, the notch strength or toughness decreases significantly at room temperature, and cracks may sometimes occur. Materials affected by hydrogen embrittlement can have their ductility and toughness restored after dehydrogenation, provided no cracks occur. Surface decarburization: Surface decarburization can occur when steel comes into contact with hydrogen. Surface decarburization does not cause cracks, but the strength and hardness of the material decrease slightly, while the elongation increases. Hydrogen corrosion: At high temperatures (above 220°C) and high pressures, hydrogen reacts chemically with impurities in the alloy (carbides or dissolved carbon) or alloying elements (such as silicon) to produce high-pressure gases. This leads to decarburization of the steel and crack formation at the crystal grain boundaries. The tensile strength, ductility, and toughness of materials subjected to hydrogen corrosion are significantly reduced. Hydrogen exfoliation: Hydrogen diffuses into the steel under high temperature and pressure. During equipment maintenance or cooling, when the temperature drops below 150°C, hydrogen cannot be released in time, and a certain amount of hydrogen remains trapped in the steel. Under specific conditions, this can lead to cracking between the surfacing layer and the base material.
It is divided into five types: hydrogen bubbling, hydrogen embrittlement, surface decarburization, hydrogen corrosion, and hydrogen exfoliation.
1 Hydrogen corrosion leads to hydrogen-induced cracking. 2 High-pressure, high-temperature hydrogen penetrates into the metal structure; rapid cooling can result in hydrogen embrittlement. 3 Methanation reactions cause a decline in the material’s properties