新型Ni-Cr-Co基高温合金在模拟煤燃烧环境中的高温腐蚀  

High temperature corrosion of new Ni-Cr-Co base superalloy in coal-fired environments

作　　者：赵双群[1] 谢锡善[1] G.D.Smith 

机构地区：[1]北京科技大学材料科学与工程学院 [2]Special Metals Corporation

出　　处：《中国有色金属学报》2004年第3期340-345,共6页The Chinese Journal of Nonferrous Metals

摘　　要：利用XRD,SEM和EDS等实验技术研究了一种新的超级超临界锅炉过热器管材Ni Cr Co基高温合金在模拟煤燃烧环境中的高温腐蚀行为。合金在700℃遭受的腐蚀过程分为2个阶段。在初始阶段,合金发生了氧化和硫化腐蚀,表面形成了保护性的Cr2O3膜,同时出现了内硫化现象。在加速腐蚀阶段,因CoSO4熔盐在合金表面的稳定存在使合金遭受严重的低温热腐蚀。当处于较高的SO3分压时,钴或氧化钴在合金表面熔盐中的溶解是造成合金抗腐蚀性能退化的原因。High temperature corrosion behavior of a new Ni-Cr-Co base superalloy, which is expected to serve as the material for the superheater/reheater tube in the ultra-supercritical boilers, was investigated in a laboratory-simulated coal-fired condition by means of XRD, SEM and EDS. The corrosion can be generally divided into two stages. The first one is an initial stage, during which a combination of oxidation and sulfidation occurr at the mean time, and the protective Cr_2O_3 scale forms on the surface and the internal sulfide appears. The second is an accelerated stage, during which severe low temperature hot corrosion happens due to the presence of the molten (CoSO_4.) The rapid degradation of corrosion resistance of alloy is attributed to the dissolution of both cobalt and cobalt oxide on the surface at high SO_3 levels.

关 键 词：NI-CR-CO 高温合金 高温腐蚀 低温热腐蚀 合成煤灰/烟气 超级超临界锅炉 过热器 

分 类 号：TK229.2[动力工程及工程热物理—动力机械及工程] TG172.82[金属学及工艺—金属表面处理]