Creep resistance of high-chromium steel and nickel-based alloy with oxidation-resistant coating for the components in advanced ultra supercritical steam generation

先进超超临界蒸汽发生部件抗氧化涂层高铬钢和镍基合金的抗蠕变性能

• 批准号: 460816-2013
• 负责人: Liu, Rong
• 金额: $ 2.19万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=618387
• 关键词: Creep; resistance; chromium; steel; nickel

The requirement of reducing the greenhouse CO2 emission has pushed the electrical power generation industry using the traditional fossil fuels to run steam turbines at temperatures above 700 degree C, which falls in the category of the so called advanced ultra supercritical (A-USC) steam turbines. To meet the high-temperature operating requirement of A-USC steam turbines (100,000 hours at 750oC), nickel-based alloy materials are to be used for parts that are directly in contact with the high temperature steam, including tubes, nozzle box (first stage nozzle), rotors and blades. Inconel 740 is one of the promising candidates. On the other hand, for economic reasons, parts that are not directly affected by the steam, for example, outer casings, are preferably made of traditional boiler materials, typically high chromium steel F91. For A-USC steam turbine components, the materials are all required to have high anti-creep strength and oxidation resistance at elevated temperatures. The existing materials, whether high Cr steels or Ni based superalloys, all exhibit deficiency in long-term creep performance because of the interference of oxidation. The available creep data for these materials were mostly obtained from short-term tests. The creep-oxidation interaction in these alloys has not been well understood as to predict their long-term behavior for application under the A USC condition. To solve these problems, the proposed research is aimed to further characterize the high-temperature creep resistance of Inconel 740 and F91; and in the meanwhile, to enhance the oxidation resistance of these substrates by applying a MCrAlY (where M represents Co, Ni or Co/Ni) coating on them; subsequently, to investigate the influence of the coating on the creep performance of these substrate materials. Since assurance by real material creep test may take a too long time for material design and characterization; a deformation mechanism based creep modeling approach will be utilized to depict the short-term creep behaviour and predict the long term creep resistance of these materials and their coating systems.

减少温室二氧化碳排放的需求已使用传统的化石燃料推动了发电行业，以在700度以上C的温度下运行蒸汽涡轮机，该蒸汽涡轮机属于所谓的Advanced Ultra超级临界（A-A-USC）类别的类别。为了满足A-USC蒸汽涡轮机的高温工作需求（750oC时100,000小时），将用于与高温蒸汽直接接触的零件，包括管，喷嘴盒（第一阶段喷嘴），转子和刀片。 Inconel 740是有前途的候选人之一。另一方面，出于经济原因，不直接受蒸汽影响的部分，例如外壳，最好是由传统锅炉材料制成的，通常是高铬钢F91。对于A-USC蒸汽轮机组件，在高温下具有较高的抗抗抗强度和氧化抗性所需的材料。由于氧化的干扰，现有的材料，无论是高CR钢还是基于NI的超合金材料，都在长期蠕变性能方面表现出不足。这些材料的可用蠕变数据主要是从短期测试中获得的。这些合金中的蠕变氧化相互作用尚未得到充分理解，可以预测其在USC条件下应用的长期行为。为了解决这些问题，拟议的研究旨在进一步表征Inconel 740和F91的高温蠕变抗性。与此同时，通过在它们上施加McRaly（M McRaly（M表示CO，Ni或Co/ni）涂层，增强了这些底物的氧化抗性；随后，研究涂层对这些底物材料蠕变性能的影响。由于实际材料蠕变测试的保证可能需要太长时间才能进行材料设计和表征。基于变形机制的蠕变建模方法将用于描述短期蠕变行为，并预测这些材料及其涂层系统的长期蠕变抗性。