燃煤流化床中氯对碳钢腐蚀的影响机制  

EFFECT OF CHLORINE ON THE DEGRADATION OF A CARBON STEEL IN A COAL-FIRED FLUIDIZED-BED COMBUSTOR

作　　者：彭晓[1] W.P.Pan J.T.Riley 

机构地区：[1]中国科学院金属研究所金属腐蚀与防护国家重点实验室 [2]Combustion Laboratory,Materials Characterization Center,Department of Chemistry,Western Kentucky University,Bowling Green,KY42101,USA

出　　处：《中国腐蚀与防护学报》2004年第4期193-197,共5页Journal of Chinese Society For Corrosion and Protection

基　　金：中科院"引进海外杰出人才"项目资助

摘　　要：在小规模流化床 (FBC)中燃烧一种低S高Cl煤 10 0 0h后 ,对放置于接近沸腾床位置的A2 10 -C碳钢管腐蚀情况进行分析 .发现在碳钢管表面温度为 4 70℃～ 5 6 0℃的区域腐蚀产物 (主要为Fe2 O3 )严重剥落 .剥落的腐蚀产物表面覆盖一层沉积盐 ,部分区域发现有 (K ,Na)Cl.对残留在钢管表面的腐蚀层进行分析 ,发现在腐蚀层 -碳钢界面或其附近的基体中出现局部氯化 ,导致形成FeCl2 层 ;局部快速腐蚀 ,形成向基体一侧的腐蚀突体 ;形成内部空洞这三种腐蚀形态 .并对此现象的产生及Cl2 的影响机制进行了详细探讨 .Corrosion of A210-C carbon steel tube has been investigated after 1000 h exposure at the place close to the bubbling bed of a bench-scale fluidized-bed combustor during firing a coal of low sulfur and high chlorine.It was found that a heavily exfoliation of the wastage occurred in locations with the tube surface temperature of 460℃～560℃.The spalled wastage was mainly composed of hematite(Fe 2O 3) covered by a layer of deposits.(K,Na)Cl was locally detected in the deposits layer.By investigation of the residual wastage on the carbon steel tube,some locations at/near the interface of the wastage and the metal substrate did appear chlorization,which led to three different consequences:(1)formation of FeCl 2 layer underneath the wastage,(2)rapid local corrosion,causing protrusions into the metal,(3)appearance of internal pores in the metal.The generation of the different morphologies above and effect of chlorine were both discussed in detail.

关 键 词：流化床 碳钢 腐蚀 氯化 

分 类 号：TG172.3[金属学及工艺—金属表面处理]