火电厂脱硫烟囱用钛/钢复合板钛复层腐蚀试验研究

Corrosion Resistance of Titanium/Steel Clad Plates for Desulphurization Chimney of Power Plants

爆炸焊钛/钢复合板已广泛应用火电厂脱硫烟囱内筒制备领域。钛/钢复合板制造电厂烟囱内筒,兼具钛板耐腐蚀的特点和钢种的优点,可以满足烟囱内筒的长期运行,确保烟囱结构的使用寿命,同时降低了成本,使得该产业符合了节约能源和保护生态环境的产业结构,越来越受到众多电厂用户青睐。本试验模拟实际工业中烟囱所处的腐蚀环境,比较了有氧化皮、去除氧化皮两种状态下的钛板的耐腐蚀特性,结果显示:有氧化皮试样的平均腐蚀速率为0.5μm/a,去除氧化皮试样的平均腐蚀速率为1.5μm/a。去除氧化皮试样的平均腐蚀速率是由氧化皮试样的3倍。对钛氧化皮成分进行分析,显示主要是金红石型TiO_2。金红石型的晶型结构均由相互连接的TiO_2八面体组成,它具有耐高温、耐低温、耐腐蚀、高强度等优异性能。根据试验结果,在成品打磨工序中取消去除氧化皮打磨工序,每张复合板可以缩短工期两天,减少打磨成本。

Explosive welding titanium/steel clad plates have been widely used in the preparation of chimney inner barrels for power plants. Titanium/steel clad plates have both the corrosion resistance of titanium alloy and the advantages of steel,so they can be used to produce chimney inner barrels for power plants to satisfy the long running of the chimney inner barrels and ensure the service life of chimney structure. In addition,the cost can be reduced,energy can be saved and the ecological environment can be protected. Therefore,they are more and more popular with power plants. In the present work,the corrosion environment of chimneys was simulated to study the corrosion resistance of the clad plates with and without oxide coating. The results show that the average corrosion rate of the specimen with oxide coating is 0. 5 μm/a,and that without coating is 1. 5 μm/a. The composition analysis of the titanium oxide coating shows that it was mainly rutile TiO2. The rutile TiO2 is composed of the interconnecting TiO2 octahedron,with high-temperature,low-temperature and corrosion resistance as well as high strength.According to the results above,the process of removing the oxide coating was eliminated in the finishing process of the finished product. As a result,the working period of each clad plate was shortened by two days,and the polishing cost was reduced.