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625合金和其他候选材料在高温（200-400℃）下的腐蚀，特别是在Teck-Cominco Trail， BC省KIVCET锅炉废气的运行条件下的腐蚀。此外，还将推荐用于锅炉管覆盖层的合适合金或与防腐有关的方法，以增加锅炉管的使用寿命。它旨在通过应用创新研究来进一步扩大知识差距。建议研究的具体目标是：(1)在Tech-Cominco的KIVCET冶炼厂对锅炉管进行彻底的失效分析，以确定失效的根本原因，并帮助了解复杂的腐蚀机理；(2)研究盐和废气成分对Alloy 625和其他潜在合金腐蚀性能的影响；(3)更好地了解Alloy 625和其他合金在锅炉工况下的腐蚀机理。使用热化学建模和实验方法，并(4)推荐最适合的合金系统应用于泰克-科米科KIVCET冶炼厂的锅炉覆盖层。该研究将包括详细的文献综述，腐蚀/失效管道的代表性样品的失效分析，代表性沉积物样品的彻底物理和化学表征以及系统的热化学分析，以确定沉积物中气相和相稳定性的稳定性和平衡，使用商业软件FactSage和HSC。此外，还将对Alloy 625和选定的候选合金进行广泛的实验测试。测试工作将分为两种类型，使用管式炉进行高温腐蚀测试，以及使用高压灭菌器和高温炉进行电化学测试。一名博士后和一名博士生将参与这个研究项目。这项工作对加拿大和Teck-Cominco的预期利益是巨大的，并将直接影响加拿大公司在全球市场上有效竞争的能力。

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.