【作者】 李世杰；

【导师】 曹晓明；

【作者基本信息】 河北工业大学 ， 材料学， 2006， 硕士

【摘要】 陶瓷锌锅内加热技术具有加热快,效率高,节约能耗,维护方便的优点,内加热管的外套管材料是整个陶瓷内加热的核心技术,要求材料必须同时具有良好的耐熔锌腐蚀性能和相应的力学性能。现在外套管所用的Fe基耐熔锌腐蚀材料存在耐腐蚀性能和机械性能不能同时满足工况条件的矛盾。耐腐蚀性能较好时,材料的机械性能很差,脆性大,容易发生热裂失效。而材料的机械性能很好时,耐腐蚀性能很差。这使得陶瓷锌锅内加热技术的应用和推广受到了极大的限制。本课题针对以上矛盾,进行了全面、深入的研究,使材料的两方面性能都得到了提高,满足了工业应用的要求。 在本课题组前面研究的基础上,我们选择在脆性相对较小,耐腐蚀性能较好的Fe-2.5B材料中添加Si、C、Mn、Mo、W等元素,本着少量多元的原则,减小各种元素的负面作用,提高材料的耐腐蚀性和机械性能。Fe-2.5B材料具有网格状结构,即共晶中的网格状硼化物包围着α-Fe基体,硼化物具有很好的耐锌蚀性能,并且网格对锌与铁的反应物有很好的阻挡作用,但是硼化物的脆性很大,α-Fe的机械性能好耐锌腐蚀能力却不足。因此如何提高α-Fe的耐腐蚀性能并细化材料的网格,是我们解决整个矛盾的关键。Si元素可以很好的固溶在α-Fe中,并且提高α-Fe的耐腐蚀能力。但是Si元素增大α-Fe晶粒,增加材料的脆性,并减少网格的数目。C元素可以很好的解决这一问题,它可以分散硼化物,增加网格的密度。Mn元素对材料的耐腐蚀性能有帮助,不降低材料的网格密度,同时提高材料的力学性能。Mo和W不但可以增加材料中网格的强度,而且在α-Fe中析出针状物,对α-Fe与锌的反应生成物有很好的钉扎作用,阻止铁锌反应物向外漂移,同样也增加了材料的耐腐蚀性能。 经过大量的试验,我们研究的Fe-2.5B-C-0.8Si-0.8Mn-4Mo-W材料具有很好的耐熔锌腐蚀性能,而且力学性能也满足工况应用的要求,目前已经在工业上应用6个多月,能够满足工业应用要求。更多还原

【Abstract】 Ceramic inner heating galvanizing has the merit of heating-up rapidly and efficiently, energy conservation and maintenance simply. The material of outer shell is the key component in Ceramic inner heating galvanizing system. It requires that the material has good corrosion resistance and corresponding mechanical properties. But the inner heater material used in galvanizing has a contradiction, the corrosion resistance and mechanical properties does not reach the galvanizing requirement at the same time. If the material has a strong resist-corrosion, the mechanical properties is weak in high temperature, brittle greatly and thermal cracked easily. While the material has a fine mechanical properties, the performance of corrosion resistance is hard to reach the inner heating requirement. So the technique extension and application of ceramic inner heating galvanizing is limited.On the basic of our former research, the alloy Fe-2.5B has excellent corrosion resistance and little brittleness. We added the elements C、 Si、 Mn、 Mo is selected, which can promote both resist-corrosion performance and mechanical properties by means of using many elements with small amount and avoiding the disadvantage of all kinds of elements. The alloy Fe-2.5B has a latticed structure, and α -Fe is included by lattice boride in eutectic. The boride has high corrosion resistant and hold the Fe-Zn reactant out ward to melting Zinc, but this kind of boride has a large brittleness, therefore its mechanical properties is not enough used to galvanizing. Mechanical properties of α -Fe is excellent but resist-corrosion is deficiency to hot galvanizing. The key factor is that improving the corrosion resistance of α -Fe and increasing the boride’slattice density. In a small amount, the Si is well solid solution in a -Fe completely, and it improve the corrosion resistance to liquid Zinc sharply. But Si enlarge the capacity of the a -Fe crystal grain growth, lower the mechanical properties of a -Fe and decrease the boride lattice density. C can disperse the boride and increase the lattice density, it can settle the question of decreasing the boride lattice density by Si. The Mn element is help the material’s corrosion resistance and didn’t decrease the boride lattice density, and it is increase the material’s mechanical properties. Mo and W not only improve the material’s mechanical properties and strength of boride lattice but also precipitate some phase as pin. It can fixed the Fe-Zn reactant hold it outer to melting Zinc and improving the corrosion resistance too.After a great deal of experiment, we find the alloy of Fe-2.5B-C-0.8Si-0.8Mn-4Mo-W has strong corrosion resistance, and the mechanical properties satisfy the industry requirements. It already applied in the industry more than 6 months and has not expired.更多还原