超音速火焰喷涂制备NiCr金属陶瓷涂层的抗高温硫腐蚀与冲蚀磨损性能

为解决燃用高硫煤的超临界、超超临界机组锅炉受热面发生的高温硫腐蚀与冲蚀磨损,采用超音速火焰喷涂技术,喷涂自主开发的NiCr金属陶瓷涂层,研究该涂层的抗高温硫腐蚀性能以及冲蚀磨损性能,并通过现场挂片试验,考察涂层经过8 000 h服役后的剥落情况。喷涂态NiCr金属陶瓷涂层孔隙率为0.55%。在700℃环境中的高温硫腐蚀试验结果表明NiCr金属陶瓷涂层具有比2Cr13高的抗高温硫腐蚀能力,同时该涂层具有较高的抗冲蚀磨损性能。该研究利用超音速火焰喷涂的NiCr金属陶瓷涂层在贵州某燃用硫含量为2.81%的高硫煤火电厂中经8000h现场挂片服役后,涂层表面完好,结果表明该NiCr金属陶瓷涂层可有效提高超临界、超超临界机组受热面的抗高温硫腐蚀和磨损性能。

Performance of HVOF NiCr Cermets Coating Against High Temperature Sulfur Corrosion and Erosion

In order to solve the high temperature sulfur corrosion and solid-particle erosion on the heating surfaces of ultra-supercritical unit fired with high sulfur content coal,high velocity oxygen fuel(HVOF) was employed to deposit the self-developed NiCr cermets coatings on 2Cr13 substrates.The performance of the HVOF NiCr cermets coating and 2Cr13 substrate against high temperature sulfur corrosion and solid-particle erosion was studied.The integrity of the coating after 8000 h in service was examined through exposure testing.The porosity of the HVOF NiCr cermets coating is 0.55%.The results of the high temperature sulfur corrosion test at 700oC and the solid particle erosion tests indicate that the developed NiCr cermets coating exhibits a high resistance to high temperature sulfur corrosion and solid-particle erosion.Spalling of the HVOF NiCr cermets coating does not occur after 8 000 hours in service in ultra-supercritical unit which fired with high-sulfur coal with a sulfur content of 2.81%.The results show that the developed NiCr cermets coating can effectively improve the performance of the heating surface against high temperature sulfur corrosion and erosion.