Investigation of oxidation and creep resistance of nickel-based alloy with superalloy hardfacing and thermal barrier coating

高温合金堆焊和热障涂层镍基合金的氧化和抗蠕变性能研究

• 批准号: 500913-2016
• 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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=657803
• 关键词: Investigation; oxidation; creep; resistance; nickel

Advanced ultra supercritical (A USC) technology allows the steam temperature raised to 700 degree C in order to increase the efficiency of coalfired power generation and reduce its CO2 emission. While the high-Cr steel used for A-USC can withstand temperatures around 600 degree C, this move to higher temperatures requires the adoption of high performance materials such as Ni based alloys. For various valves operating in boiler, pipework and steam turbines of A-USC power generation plants, Inconel 740 and Haynes 282 have been selected for the body or base materials. To enhance the surface wear/erosion resistance, theses alloys are usually coated with Stellite alloy (Stellite 6) hardfacing. However, it has been found in recent years that Stellite 6 hardfacing degrades in the A-USC conditions and fails in service after a period of time. As a result, there is a strong demand from the valve industry, for example, Velan Inc., for an effective hardfacing material which can sustain the high temperature while they are resistant to wear and erosion. The proposed research attempts to apply a newly developed high performance Tribaloy alloy T-400C on Inconel 740 or Haynes 282 surface via plasma transferred arc (PTA) welding or laser cladding. The hardfacing specimens will be investigated under oxidation and creep tests. On the other hand, in order to reduce the temperature that directly acts on the Ni based alloy, thermal barrier coating (TBC) will be applied on Inconel 740 or Haynes 282; the coating system consists of a metallic bond coat and a ceramic topcoat composed of yttria-stabilized zirconia (YSZ). The oxidation and creep resistance of the coating specimens will be investigated at high temperatures between 650 and 850 degree C. Long-term creep test takes too long time and is impossible to be implemented in laboratory. Therefore a deformation mechanism based creep model for these coating/substrate systems will be developed to depict their short-term creep behaviour and meanwhile predict their long term creep resistance. The outcomes of this research will help reduce the costs of materials and equipment maintenance of the coal-fired power generation industry, with improving the efficiency of power generation technologies.**************************

先进的超超临界（A USC）技术可将蒸汽温度提高至700摄氏度，以提高燃煤发电的效率并减少二氧化碳排放。虽然 A-USC 使用的高铬钢可以承受 600 摄氏度左右的温度，但向更高温度的转变需要采用高性能材料，例如镍基合金。对于 A-USC 发电厂锅炉、管道和汽轮机中运行的各种阀门，阀体或基材均选用 Inconel 740 和 Haynes 282。为了增强表面耐磨/耐腐蚀性，这些合金通常涂有司太立合金（司太立6）硬面。然而，近年来发现Stellite 6硬面在A-USC条件下会退化，并在使用一段时间后失效。因此，阀门行业（例如 Velan Inc.）对一种有效的堆焊材料有着强烈的需求，这种材料可以承受高温，同时耐磨损和耐腐蚀。拟议的研究尝试通过等离子转移弧（PTA）焊接或激光熔覆在Inconel 740或Haynes 282表面上应用新开发的高性能Tribaloy合金T-400C。硬面样本将在氧化和蠕变测试中进行研究。另一方面，为了降低直接作用于镍基合金的温度，会在Inconel 740或Haynes 282上施加热障涂层（TBC）；该涂层系统由金属结合层和由氧化钇稳定氧化锆（YSZ）组成的陶瓷面漆组成。涂层试样的抗氧化和抗蠕变性能将在650至850摄氏度之间的高温下进行研究。长期蠕变测试需要很长的时间，并且不可能在实验室中实施。因此，将开发这些涂层/基材系统的基于变形机制的蠕变模型，以描述其短期蠕变行为，同时预测其长期抗蠕变性能。这项研究成果将有助于降低燃煤发电行业的材料和设备维护成本，提高发电技术的效率。******************** *********