摘要：Galvalume镀层钢板由于结合了镀铝层的持久性和镀锌层的牺牲阳极保护性能等优越性能，从而具有优良的耐腐蚀性能，近年来在建筑等行业得到迅速发展。在Galvalume熔池加入合金元素对钢板镀层的生长和性能会有较大影响。
本文研究了在Galvalume熔池中添加不同含量Si和Ti元素对热浸镀层组织和厚度的影响。将锌铝熔池温度控制在6005℃，使用纯铁片作为基体进行热浸镀实验，观察添加合金元素对熔池和镀层表面形貌的影响；采用扫描电镜对镀层截面形貌进行观察，同时采用能谱仪分析镀层金属间化合物层中各相的成分，并且对镀层金属间化合物的生长动力学进行了分析研究。
研究结果表明，在55%Al-Zn熔池中未添加Si元素时，铁和铝之间发生剧烈的放热反应，使得合金层中出现大量含锌的铁铝相，Fe2Al5-Znx相仅出现在铁基附近，而大量的FeAl3-Znx相呈层状出现在离基体较远处，在FeAl3-Znx相层之间存在大量的锌铝液相。当Si元素被加入到熔池之后能抑制铁铝之间的反应，仅需1.0%的添加量即使得金属间化合物层减薄，在适当的浸镀时间能维持平直状态，Si含量增加到3.0%时该抑制效果更为明显。在Galvalume熔池中添加少量的Ti得到的钢板镀层表面比较光亮平整，同时金属间化合物明显减薄，Ti添加量达到0.2%时其厚度达到一个较低的值，随后Ti含量进一步增加对镀层的生长的影响不大。
关键词：硅；钛；Galvalume；热浸镀锌铝；金属间化合物
Abstract:Galvalume coatings on steel strips have a superior performance, it combines the good durability of an aluminum coating and the sacrificial characteristics of a zinc coating, which has excellent corrosion resistance. In recent years in the construction sector is rapid development. Galvalume bath by adding alloying elements have a greater impact on the growth and performance of steel plate coating.
This paper investigated the effects of adding different content of Si and Ti to Galvalume bath on the structure and thickness of hot-dip coating. Zinc-aluminum bath temperature control in 600 5℃ ,then pure iron samples were hot-dipped in the alloy bath containing additives, observation of molten pool and coating surface morphology by adding alloying elements. Coating cross-section morphology were observed using scanning electron microscopy, while using energy dispersive analysis of the composition of each phase in the coating metal intermetallic compound layer, And growth kinetics of intermetallic compounds in the coating were analyzed.
The results show that a large number of zinc-containing Fe-Al phase in the alloy layer due to a violent exothermic reaction occurs between the iron and aluminum when the 55%Al-Zn bath did not add Si. Fe2Al5-Znx phase appears only in the vicinity of the iron substrate, while large number of the layered FeAl3-Znx phase was appeared more distant from the substrate. A lot of liquid zinc-aluminum phase layer between FeAl3-Znx.The reaction is inhibited between the Fe-Al when Si is added to the bath, only 1.0% of the addition even with the intermetallic compound layer thinning, straight state can be maintained at the appropriate dipping time. The inhibitory effect is more obvious when the Si content to 3.0%.Adding a small amount of Ti element makes the surface of the strip coating is shiny and smooth in the Galvalume bath, simultaneously intermetallic compounds significantly thinning. Its thickness at a lower value as the Ti content is added to 0.2%.Followed by Ti content further increase has little effect on the growth of the coating.
Keywords: Si; Ti; Galvalume; hot-dipping Zn-Al; intermetallics
