白云鄂博矿含氟烧结料对高铬铸铁篦条失效行为的影响

Effect of Fluorine-containing Material of Bayan-obo Ore on Failure of High Chromium Cast Iron Grate Bars of Sintering Facility

利用扫描电镜(SEM)观察白云鄂博矿烧结用失效高铬铸铁篦条的表面氧化膜形貌,进行成分能谱分析(EDS),测定氧化膜中氟含量,结合X射线衍射(XRD)对氧化膜进行物相分析,分析含氟烧结料用高铬铸铁篦条的失效机理.结果表明,在高温运行中,烧结料的F、S、Na、K等使篦条基材产生腐蚀,篦条腐蚀膜中结构疏松的Na_2SO_4、K_2SO_4、FeF_3和低熔点Ni·NiS共晶使其表面不能形成致密连续的腐蚀膜,从而造成失效.

Scanning electron microscope（SEM） was used to observe the surface morphology of oxide scales of failed high chromium cast iron grate bars of the facility for treating the sintered ore bearing materials from Bayan-obo,while the chemical composition analysis was carried out using EDS and the fluorine content in corrosion scales was measured,moreover,the phase constituents of corrosion scales was characterized by XRD analysis.The failure mechanism of the high chromium cast iron furnace grate bars for sintering of the fluorine-containing material of Bayan-obo ore was investigated.The results showed that F,S,Na K etc.in the sintering material would induce corrosion of the grate during high temperature operation,while the presence of Na_2SO_4,K_2SO_4, FeF_3 porosity and eutectic Ni-NiS with low melting point,might retard the formation of continuous and dense corrosion scales on the grate surface,which was the main reason of the grate failure.