High temperature corrosion of boiler steels in hydrochloric atmosphere under oil shale ashes

High temperature corrosion in power plants is a main breakdown criterion in boiler applications. This study is focused on the high-temperature corrosion resistance of several boiler steels used in Estonian power plants, which were experimentally tested in gaseous hydrochloric environment combined with Estonian oil shale ashes in a high temperature corrosion test up to 600 °C. Scanning electron microscopy supported by energy dispersive X-ray spectroscopy was used to reveal different corrosion mechanisms. Results indicate a strong dependence of the boiler steel corrosion to the present anions in the oil shale ash and their removal in the boiler.     

氯碱生产输送系统中的腐蚀与保护

针对氯碱生产过程中输送管线系统的腐蚀情况进行了现场分析和非现场研究．结果表明：应力腐蚀破裂和杂散电流腐蚀是该输送管线产生破坏的两种主要原因．在此基础上，提出了一系列可行的防护措施．     

Data mining to effect of key alloying elements on corrosion resistance of low alloy steels in Sanya seawater environmentAlloying Elements

In this paper,the relationship model between seawater environment,chemical composition and corrosion potential of low alloy steel is established and the distribution of corrosion potential of low alloy steel with changes in key alloying elements is excavated.The research was carried out with the following steps:Firstly,the relationship model between corrosion potential of low alloy steel and its influencing factors was established by data dimension reduction and artificial neural network(ANN).Secondly,key alloying elements of experimental steels were selected out by Pearson correlation analysis,then the corrosion resistance element model was visualized to show the effect of key alloying elements on corrosion potential of low alloy steel.Finally,corrosion potential of low alloy steel with the change of key alloying elements was classified and visualized by classification method.The mining results can reflect the validity of the proposed mining methods to a certain extent and provide an intuitive data basis for the development of high-quality and low-cost low alloy steels.     

一种改性聚乙烯醇水基憎水剂的研究

研究了一种以聚乙烯醇为基质,辅以两种非离子表面活性剂Span-80和Tween-80及水溶性缓蚀剂的水基憎水剂,用来处理钢铁试样.考察了聚乙烯醇的聚合度及醇解度、两种非离子表面活性剂之间的配比、聚乙烯醇含量、乳化剂含量、水溶性缓蚀剂含量以及预处理和后处理等因素对憎水剂憎水效果及稳定性的影响.实验表明,用该憎水剂处理的钢材试样在3%NaCl溶液中240h内不出现腐蚀点,在4%CuSO4溶液35min内不变色,接触角可达98..有望替代某些溶剂基憎水剂.     

铝基表面等离子喷涂Al2O3-TiO2-Ta涂层的制备及防腐性能

采用等离子喷涂技术在铝基表面构建Al₂O₃-TiO₂涂层和Al₂O₃-TiO₂-Ta涂层。由于钽元素的引入,Al₂O₃-TiO₂-Ta涂层表面形貌更均匀、致密。同时钽金属具有极强的耐酸碱特性,因此,Al₂O₃-TiO₂-Ta涂层相对于Al₂O₃-TiO₂涂层具有更强的耐腐蚀性。Tafel曲线结果显示,Al₂O₃-TiO₂涂层使得基体的腐蚀电位仅正移了99.6 mV,Al₂O₃-TiO₂-Ta涂层使得铝基体腐蚀电位正移了208.9 mV。因此,由于耐蚀性极强的Ta金属的掺入,Al₂O₃-TiO₂涂层的防腐性得到了极大的增强,Al₂O₃-TiO₂-Ta涂层有效地防止铝合金腐蚀。     

氯碱工业系统的腐蚀与防护

分析了氯碱工业系统制备盐水、盐水电解、碱液蒸发和氯气处理过程中介质的腐蚀特性,提出了具体的防腐蚀措施,诸如应用衬里技术、涂层技术、电化学保护技术等防腐蚀新技术,以及包括工程塑料、玻璃钢、橡胶等耐腐蚀非金属材料,来控制设备的腐蚀,从而确保装置的长周期运行。     

激光熔覆工艺对铁基合金熔覆层耐蚀性影响的研究

采用不同熔覆工艺进行了铁基粉末的熔覆试验, 结果表明, 随着熔覆功率的增大, 熔覆层组织逐渐变粗大, 耐蚀性下降。 通过腐蚀位置组织结构观察发现, 腐蚀沿晶界从熔覆层表面向内部发展, 并逐渐向晶粒内部发展。 枝晶间的硼化物成分组成改变及碳化物在冷却过程中析出造成基体进一步贫铬, 是熔覆层耐蚀性下降的主要原因。     

38CrMoAIA钢可控抗蚀氮化

介绍可控井式氧化炉合理控制氮化温度、时间和氨分解率的渗氮 艺,使38CrMoAlA钢试样表面获得致密而无脆的ε相白亮层和扩散层渗层组织,渗氮后试样实测表明,该试样显微组织、脆性、显微硬度、渗层深度和抗蚀性均符合技术要求。     

热镀用锌铋多元合金的研制

介绍了实验室条件下配制锌铋多元合金的方法和工艺,模拟热镀锌操作工艺进行了锌铋多元合金的热镀试验,并对镀层进行了盐雾腐蚀试验和金相组织检测。确定了锌铋多元合金的最佳配方。     

阴极改进法在耐蚀合金研究中的应用

综述了阴极改进法的原理、方法在各种合金系统中的实际应用以及阴极改进合金在酸性介质中的腐蚀行为.