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

该项目旨在对高合金铁铬合金在 SO2 和 H2O 下以及含氯沉积物 (KCl) 下的热气体气氛中的损伤机制进行基础研究。这些材料用作各种燃烧发电厂的热交换器管材料。生物质和生物质混燃发电厂所用材料的烟气侧损坏是一个严重的问题，并限制了此类发电厂的运行温度。 将通过随时间变化的老化实验在降解的早期阶段研究腐蚀产物结晶和生长的基本方面。高纯度模型合金（Fe-Cr）和模型气体成分用于重点关注所涉及元素 Fe、Cr、S 和 Cl 的反应。使用广泛的经典显微镜技术和先进的表征方法（例如 X 射线近边缘结构吸收光谱 (XANES)）对形成的腐蚀区域进行定性和定量相分析。经典显微镜与 XANES 的结合可以对现有反应产物进行极其精确的验证。这种方法应该有助于显示金属离子和气体成分在反应产物晶体结构上的扩散和传输路径。在专门设计的光反应堆中，将在反应过程中通过原位能量色散 X 射线衍射直接跟踪腐蚀早期阶段的结晶和生长。该项目旨在解决三个问题。第一个目标是研究保护性 Cr2O3 的形成。为此，使用了允许材料暴露于热烟气的实验装置。首先，对三种不同的高合金（Cr>15Ma%）模型合金进行时效试验，反应时间12h