热循环对喷瓷管道瓷层耐蚀性的影响  

Influence of Thermal Cycles on the Coating Corrosion Resistance of Sprayed Porcelain Pipe

作　　者：王勇[1] 韩涛[1] 张文钺[2] 

机构地区：[1]石油大学机电工程学院,山东东营257061 [2]天津大学材料科学与工程学院,天津300072

出　　处：《焊接学报》2001年第6期15-17,共3页Transactions of The China Welding Institution

基　　金：高等学校骨干教师资助计划项目 (K0 0 0 30 7A)

摘　　要：采用焊接热模拟、电化学测试、扫描电镜、X射线衍射等方法研究了热循环对喷瓷管道瓷层耐蚀性的影响。结果表明 ,焊接热循环改变了瓷层的相结构 ,峰值温度低于 12 0 0℃时瓷层相结构主要为玻璃态 ,有少量晶相析出 ,峰温为 135 0℃时瓷层全部转变为玻璃态。随峰值温度的改变 ,瓷层的耐蚀性发生变化 ,峰温 135 0℃时耐蚀性最好 ,峰温 12 0 0℃时耐蚀性最差。峰温低于 95 0℃时 ,由于加热温度低 ,瓷层熔体的粘度大 ,流动性差 ,瓷层结构基本未变 ,与原始试样相比 ,耐蚀性变化不大。峰温 70 0℃时 ,由于瓷层表面存在微裂纹 ,瓷层发生塌陷腐蚀。瓷层与金属之间发生了一系列复杂的物理化学反应 ,形成过渡层 ,层厚度约 30 μm ,基体金属以岛状和桥状与瓷层连接 ,过渡层中形成大量晶相 。The influence of thermal cycles on the enamel coating corrosion resistance was investigated by Weld Thermal Simulation,Electro chemical Technique,SEM and XRD.The results show that the structure of enamel coating at peak temperature 1350℃ is examined as full vitresence ,while the structure after cyclic heating at low peak temperature is mainly vitresence together with crystalline phase .At different peak temperature ,the coating corrosion resistance of sprayed porcelain pipe is different.The best is at 1 350 ℃ and the worst is at 1 200 ℃ .When the peak temperature is under 950℃,the viscosity of the enamel smelt is big,which makes the smelt have poor flowability,so the structure and the anti corrosion property of the enamel coating have no great changes.But micro cracks occur on the surface of the coating at 700℃,and the anti corrosion property will go down obviously.When it is corroded,the enamel coating sinks.A series of complicated physical and chemical reactions take place between metal and enamel coating,so as to produce many crystalline phases.A transition layer about 30μm width is formed on the interface where alloy phases are existed in the shapes of island and clump.The anti corrosion property decreases.

关 键 词：喷瓷管道 瓷层 焊接热循环 耐蚀性 

分 类 号：TG174.45[金属学及工艺—金属表面处理]