A fundamental study on high temperature corrosion of boiler tubes in smelting off-gas environments

拟议项目的总体目标是开展一项研究，以更好地了解合金625和其他候选材料在高温（200 - 400 C）下的腐蚀情况，特别是在不列颠哥伦比亚省Teck-Cominco Trail的KIVCET锅炉废气中的操作条件下。此外，将推荐用于锅炉管覆盖层的合适合金或与防腐相关的方法，以增加锅炉管的使用寿命。其目的是通过应用创新研究来进一步缩小知识差距。拟议研究的具体目标是：（1）对Tech-Cominco的KIVCET冶炼厂的锅炉管进行彻底的失效分析，以确定失效的根本原因并帮助理解复杂的腐蚀机理，（2）研究盐和废气成分对合金625和其他潜在合金的腐蚀性能的影响，（3）利用热化学模拟和实验方法，对625合金和其他合金在锅炉条件下的腐蚀机理提供更好的基本理解;（4）推荐最适合在Teck-Cominco KIVCET冶炼厂用作锅炉覆盖层的合金系统。该研究将涉及详细的文献综述、腐蚀/失效管道代表性样品的失效分析、代表性存款样品的全面物理和化学表征，以及将使用商业软件FactSage和HSC对系统进行热化学分析，以确定存款中气相和相稳定性的稳定性和平衡。此外，还将对625合金和选定的候选合金进行广泛的实验测试计划。测试工作将分为两种类型，使用管式炉的高温腐蚀测试和使用高压釜和高温炉的电化学测试。一名博士后研究员和一名博士。学生们将在这个研究项目中工作。这项工作对加拿大和Teck-Cominco的预期利益是巨大的，将对加拿大公司在全球市场上有效竞争的能力产生直接影响。

The overall objective of the proposed project is to mount a study to develop a better fundamental understanding of the corrosion of alloy 625 and other candidate materials at high temperatures (200-400 C) and specifically under operating conditions prevailing in the KIVCET boiler off-gas at Teck-Cominco Trail, BC, operation. In addition, suitable alloy(s) for the boiler tube overlay or methods relating to corrosion protection which would increase the service life of the boiler tubes will be recommended. It is intended to further the knowledge gap by applying innovative research. Specific objectives of the proposed research are: (1) to carry out a thorough failure analysis of boiler tubes at Tech-Cominco's KIVCET smelter to define root cause of failure and assist in understanding the complex corrosion mechanism, (2) to study the effects salts and the composition of the off-gas on the corrosion performance of Alloy 625 and others potential alloys, (3) to provide a better fundamental understanding of corrosion mechanism of Alloy 625 and other alloy under the boiler conditions, using both thermochemical modeling and experimental approaches and (4) to recommend the best suitable alloy systems for application at as boiler overlay at Teck-Cominco KIVCET smelter. The study will involve a detailed literature review, failure analysis on representative samples of corroded / failed tubing, thorough physical and chemical characterization of representative deposit samples and thermochemical analysis of the system will be undertaken to determine the stability and equilibria in both the gas phase and phase stability in the deposits, using commercial software FactSage and HSC. Also, an extensive experimental testing program on Alloy 625 and selected candidate alloys will be performed. The testwork will be divided into two types, high temperature corrosion testing using a tube furnace, and electrochemical testing using an autoclave, and high temperature furnace. A post doctoral fellow and a Ph.D. student will work on this research project. The anticipated benefits of the work to Canada and to Teck-Cominco are significant and will have a direct impact on the ability of Canadian companies, to compete effectively in the global market.