Degradation and protection phenomena of high-alloy Fe-Cr alloys in hot, multi-component gas systems

高合金铁铬合金在热多组分气体系统中的降解和防护现象

• 批准号: 416318834
• 负责人: Professor Dr. Timm John, since 10/2021
• 金额: --
• 依托单位: Institut für Geologische Wissenschaften
• 依托单位国家: 德国
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/416318834?language=en
• 关键词: Degradation; protection; phenomena; alloy; Fe

The proposed project aims at the fundamental investigation of the damage mechanisms of high-alloyed Fe-Cr alloys in a hot gas atmosphere under SO2 and H2O and under chlorine-containing deposits (KCl). These materials are used as materials for heat exchanger tubes in various combustion power plants. The damage to the flue gas side of the materials used in biomass and biomass co-fired power plants is a serious problem and limits the operating temperature of such plants. Fundamental aspects of crystallization and growth of corrosion products will be investigated at an early stage of degradation by means of time-dependent ageing experiments. High purity model alloys (Fe-Cr) and model gas compositions are to be used to focus on the reaction of the elements Fe, Cr, S and Cl involved. The qualitative and quantitative phase analysis of the formed corrosion zones is performed using a broad spectrum of classical microscopy techniques and advanced characterization methods, such as X-ray near-edge structure absorption spectroscopy (XANES). The combination of classical microscopy with XANES leads to an extremely precise verification of the existing reaction products. This approach should help to show diffusion and transport paths of metal ions and gas components over the crystal structure of the reaction products. Crystallization and growth at a very early stage of corrosion will be followed directly during the reaction by in-situ energy dispersive X-ray diffraction in a specially designed light reactor.The project aims at three questions. The first objective is to investigate the formation of protective Cr2O3. For this purpose, an experimental setup is used that allows materials to be exposed to a hot flue gas. First, ageing tests are carried out on three different high-alloyed (Cr>15Ma%) model alloys with reaction times 12h

拟议的项目旨在对SO2和H2O下以及含氯的沉积物（KCL）的热气大气中高合金Fe-Cr合金的损伤机理进行基本研究。这些材料被用作各种燃烧发电厂中的热交管试管的材料。生物质和生物质共同燃料发电厂中使用的材料的烟气侧的破坏是一个严重的问题，并限制了此类植物的工作温度。 结晶和腐蚀产物生长的基本方面将在降解的早期阶段通过时间依赖性的衰老实验进行研究。高纯度模型合金（FE-CR）和模型气体组成应用于专注于涉及的元素Fe，Cr，S和Cl的反应。使用广泛的经典显微镜技术和高级表征方法（例如X射线近边缘结构吸收光谱（XANES））进行形成的腐蚀区的定性和定量相分析。经典显微镜与XANES的组合导致对现有反应产物的极为精确的验证。这种方法应有助于显示金属离子和气体成分在反应产物的晶体结构上的扩散和传输路径。在反应期间，在非常早期的腐蚀早期阶段的结晶和生长将通过特殊设计的光反应器中的原位X射线衍射直接遵循。该项目的目的是三个问题。第一个目的是研究保护性CR2O3的形成。为此，使用了实验设置，该设置允许材料暴露于热烟气中。首先，对具有反应时间12H的三个不同高合金（Cr> 15ma％）模型进行衰老测试