摘要：熱浸鍍鋅鋁合金鍍層是現(xiàn)代工業(yè)大量使用的金屬鍍層。由于腐蝕問題遍及國民經(jīng)濟(jì)和人類活動的各個領(lǐng)域，大量的工程構(gòu)件、設(shè)備和設(shè)施因腐蝕而失效，給國家?guī)砭薮蟮慕?jīng)濟(jì)損失。目前我們使用最廣泛的是70年代問世的Galvalume鋁鋅硅熱鍍合金（55％Al-43.4％Zn-1.6%Si）。但是，Galvalume合金鍍層過厚、熔池中渣量過多的問題嚴(yán)重影響了產(chǎn)品質(zhì)量。研究表明，底渣形成主要原因是熔池中過飽和的鐵含量及熔池密度過低。通過降低鋅鋁熔體中鋁含量的方法，可以有效降低浸鍍溫度，從而降低鋅池中的鐵含量及鐵、鋁之間的放熱反應(yīng)，持續(xù)有效地降低鋅池中鐵的溶解度，減少鋅池中的鋅渣生成量，并使鋅池中有限的鋅渣由底渣轉(zhuǎn)化為浮渣，即具有使浸鍍過程中產(chǎn)生的作為鋅渣主要成分的FeAl3由底渣變成浮渣的功能。本實驗通過合金化的方法，在Zn-30%Al熔池中加入合金元素Mg和Si，以期找到在降低鋁含量的前提下，有效控制合金鍍層厚度并提高鍍層耐蝕性能。

　　　本文利用掃描電鏡、能譜儀研究了560℃情況下，Q235鋼在Zn-30%Al-x%Mg、Zn-30%Al-1.1%Si-x%Mg等不同熔池中浸鍍不同時間后鍍層合金層組織生長的變化規(guī)律；利用電化學(xué)方法，研究了Mg、Si協(xié)同作用對熱浸Zn-30%Al-1.1%Si-1.0%Mg鍍層耐蝕性的影響。獲得如下結(jié)果：

　　1、在Zn-30%Al熔池中Mg的加入有利于減緩浸鍍過程中的放熱反應(yīng)，對合金層的生長具有明顯的抑制作用。

   2、在Zn-30%Al熔池中加入Si元素后，可以減緩鐵鋁之間的放熱反應(yīng)，有效減薄合金層厚度；同時隨著合金元素Si的加入，會改變鋼基界面生成合金相的種類，由Zn-30%Al-x%Mg合金層的FeAl3相轉(zhuǎn)變?yōu)閆n-30%Al-1.1%Si-x%Mg合金層的τ5C相。

　　3、在Zn-30%Al-1.1%Si熔池中加入Mg元素，Mg、Si協(xié)同作用能進(jìn)一步減薄合金鍍層，實驗時加入1%Mg效果最好。當(dāng)Mg超過一定含量，則會使得熔池流動性變差，產(chǎn)生漏鍍現(xiàn)象。

   4、Mg、Si協(xié)同作用對鍍層耐蝕性實驗表明Zn-30%Al-1.1%Si-1.0%Mg鍍層的耐蝕性優(yōu)于Galvalume。

關(guān)鍵詞：合金層，耐蝕性，動力學(xué)，Mg，Si

Abstract: Hot-dip galvanized aluminum alloy coating is the extensive use of modern industrial metal coating. Corrosion problems throughout the national economies and human activities in various fields of engineering components, equipments and facilities due to corrosion and failure to bring about huge economic losses to the state. Currently the most widely used is the advent in the 1970s, Galvalume aluminum zinc silicon alloy (55% Al-43.4% Zn-1.6% Si). Galvalume alloy coating is too thick, however, the excessive amount of slag of molten pool seriously affect the quality of the product. Studies have shown that the bottom ash formed mainly due to the molten bath saturated iron content and low bath density. By reducing the aluminum content in the melt of zinc aluminum, can effectively reduce the dip temperature, thereby reducing the zinc pool iron content and the exothermic reaction between the iron, aluminum, and continue to reduce the solubility of zinc in the pool of iron, to reduce zinc pool zinc dross generation, limited zinc pool and zinc ash, bottom ash is converted to the scum, that is to dip the bottom ash as a main component of the zinc slag FeAl3 become dross function. In this study, by alloying, in Zn-30% Al bath by adding alloying elements Mg and Si, in order to find the premise of lower aluminum content, effective control of the alloy coating thickness and coating corrosion performance.

　　　By using scanning electron microscopy, energy dispersive spectroscopy to study the case of 560 ℃, Q235 steel in Zn-30% Al-x% of Mg, Zn-30% Al-1.1% Si-x% Mg bath immersed plated at different times after the coating alloy layer growth variation. By using electrochemical methods, the study of Mg, Si synergistic effect on the corrosion resistance of hot dip Zn-30% Al-1.1% Si-1.0% Mg coating. The following results:

　　　1、In Zn-30% Al bath of Mg join conducive to slow exothermic reaction in the dip, significantly inhibited the growth of the alloy layer.   

　　　2、Si elements in Zn-30% Al bath, can slow the exothermic reaction between the Fe-Al and effective reduce alloy layer thickness; at the same time with the addition of alloying elements Si steel substrate interface generation alloy phase species, the Zn-30% Al-x% Mg alloy layer FeAl3 into the Zn-30% Al-1.1% Si-x% Mg alloy layer τ5C phase.

　　　3、By mg element in the Zn-30% Al-1.1% Si bath, Mg, Si synergistic effect can further thin of the alloy coating, experiment by adding 1% of Mg is the best. When Mg exceeds a certain content will be making the weld pool fluidity variation to produce uncoated phenomenon.   

　　　4、Mg, Si synergistic effect on the corrosion resistance experiments show that the corrosion resistance of Zn-30% Al-1.1% Si-1.0% Mg coating is better than Galvalume.

Key word: alloy layer，corrosion resistance，dynamics，Mg，Si