摘要
采用模拟密集颗粒对换热管底部的冲击作用的装置， 研究氯化物对埋入燃烧床中管材耗损的影响及其机制．结果表明ＨＣｌ加剧材料的耗损，其耗损率随温度升高而上升．同时研究磨损表面和腐蚀产物的显微组织和化学组成的特征．ＨＣｌ对耗损率的影响主要在于它促进氧化并降低氧化膜的粘附性．
Heat\|exchanger tubes in fluidized bed combustors (FBCs) often suffer from material loss due to combined corrosion and erosion. To further understand the effect of chlorine on in\|bed tube wastage, a FBC wastage simulator was used to carry out the study. The later was designed to simulate dense particle impacts on the tube bottoms with well\|controlled parameters, and has been proven to closely reflect situation found in operation bubbling FBCs. HCl gas was chosen to be the Cl source and was introduced into the fluidizing air with a dose of 50×10 -6 . Tests were performed at temperatures from ambient to 400℃ with samples made of 1018 low carbon steel rods and a bed consisted of commercial SiO 2 sand with average size of 800 μm. The wear profiles after each test was measured using a profilometer. Results showed that the presence of HCl increased the material wastage rates and the rate was significant higher at higher temperatures. The results of microstructural and chemical analysis of the wear surface and corrosion products are also reported. It is concluded that the dominating effect of HCl on the wastage rates is due to an enhanced oxidation and a reduced scale adherence.
出处
《腐蚀科学与防护技术》
CAS
CSCD
1999年第6期321-329,共9页
Corrosion Science and Protection Technology
基金
国家自然科学基金
美国电力研究所资助
