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在锅炉防护用涂层材料的研制及其抗高温腐蚀性能和机理的研究方面作了一些探索性的工作。在国内首次设计并研制成功铬含量在40wt％以上的新型高铬镍基合金,并将其制备成可供电弧喷涂用的丝材。 采用电弧喷涂技术制备出新型高铬镍基合金涂层。对其抗高温氧化、抗H_2S、SO_2腐蚀以及抗热腐蚀的性能和机理进行了系统研究,得到如下结论:(1)在大气环境下,较高的Cr含量使涂层发生了选择氧化,在表面形成了连续的Cr_2O_3氧化膜,它对元素的扩散可起到有效的抑制作用。(2)在SO_2/O_2(1:4)气氛下,涂层表现出优秀的抗硫氧化物腐蚀性能。发现Cr在涂层中所起的作用为:①形成Cr_2O_3保护层以抑制元素的扩散;②捕获Ni_3S_2中的S,从而减少了低熔点共晶体Ni-Ni_3S_2的出现。(3)在H_2S(10％)气氛下,涂层表现出优异的抗硫化腐蚀性能。发现Cr元素对镍基合金抗高温硫化性能的提高是通过在腐蚀产物内层形成富铬区(Cr以硫化物的形式存在)来实现的,该富铬层的存在应能起到抑制涂层未腐蚀部分金属元素向外扩散和腐蚀介质向内侵入的作用。(4)在Na_2SO_4/K_2SO_4(7:3)盐膜作用下,涂层表现出优异的抗热腐蚀性能。较高的Cr含量使得该高铬镍基合金涂层位于表面Ni的硫化物下面的部分发生了选择氧化,形成了连续的Cr_2O_3氧化膜,从而有效地
Some exploratory work has been done on the research of the boiler protective coating material and its research on the performance and mechanism of high temperature corrosion resistance. For the first time in China, a new type of high chromium nickel-based alloy with a chromium content above 40wt% has been successfully designed and prepared into a wire material for arc spraying. A new type of high chromium nickel-base alloy coating was prepared by arc spraying. The properties and mechanisms of high temperature oxidation, anti-H 2 S, SO 2 corrosion and hot corrosion resistance were systematically studied. The conclusions are as follows: (1) In the atmosphere, the higher Cr content resulted in the selective oxidation of the coating. Surface formed a continuous Cr_2O_3 oxide film, which can play an effective element of the proliferation of inhibition. (2) Under SO 2 / O 2 (1: 4) atmosphere, the coating shows excellent anti-sulfur oxide corrosion resistance. It is found that Cr plays a role in the coating as follows: ① forming Cr 2 O 3 protective layer to suppress element diffusion; ② capturing S in Ni 3 S 2 so as to reduce the occurrence of Ni-Ni 3 S 2 with low melting point. (3) The coating shows excellent anti-sulfidation corrosion resistance under a H 2 S (10%) atmosphere. It was found that the improvement of the high temperature vulcanization performance of the Cr-based alloy on the Ni-based alloy is achieved by the formation of a chromium-rich zone (Cr in the form of sulfide) in the inner layer of the corrosion product. The chromium- Non-corrosive metal elements outward diffusion and corrosive medium inward intrusion. (4) Under the Na2S04 / K_2SO_4 (7: 3) salt film, the coating shows excellent hot corrosion resistance. The higher Cr content causes the selective oxidation of the portion of the high-chromium-nickel-base alloy coating below the surface Ni sulfide to form a continuous Cr 2 O 3 oxide film, thus effectively