【摘要】：熱浸鍍鋅技術(shù)發(fā)明至今已有300多年的歷史,發(fā)展至今,仍然是鋼鐵防護(hù)最有效的方法。人們對(duì)熱浸鍍鋅的研究多集中在鍍層形成后的鍍層組織及耐腐蝕性能,但是對(duì)鍍層有重要影響的鋅浴的研究甚少,鑒于此,本文基于國家基金項(xiàng)目“鋅浴特征及鍍層性能的預(yù)控制研究”的選題,對(duì)鋅浴的結(jié)晶特性、表面張力及流動(dòng)性進(jìn)行研究,為預(yù)判模型的建立提供鋅浴液態(tài)性能的理論基礎(chǔ)。配制了本課題所需 Zn、Zn～0.05%Al、Zn～0.1%Al、Zn～0.2%Al、Zn～0.3%Al、Zn～0.5%Al、Zn～0.2%Al～0.2%RE、Zn～0.2%Al～0.3%RE合金,采用熱分析法,測試、分析了鋅及鋅合金浴在430℃～520℃溫度下的完整冷卻曲線,并采用數(shù)學(xué)算法算出微分曲線,很據(jù)冷卻曲線的特征值求出過冷度,分析了溫度、鋁及稀土對(duì)鋅浴結(jié)晶特性及過冷度對(duì)鋅浴組織的影響。采用吊板法測試了鋅浴的表面張力,分析了溫度、鋁及稀土(RE)對(duì)鋅浴表面張力的影響;利用金屬型澆注模型澆鑄法分析了鋅浴的流動(dòng)性,分析了溫度、鋁、稀土對(duì)鋅浴流動(dòng)性的影響。本論文通過研究得出以下結(jié)論:純鋅浴的有效形核過冷度在430℃時(shí)為16.1℃,遠(yuǎn)小于純鋅的均勻形核過冷度83.9℃,純鋅浴按非均勻形核冷卻。在430～520℃,純鋅浴的過冷度為16.1～7.6℃,隨著澆注溫度的升高,過冷度遞減,實(shí)際結(jié)晶溫度越低。在澆注溫度相同的條件下,鋁含量的增加促進(jìn)了鋅浴的異質(zhì)形核,使形核界面能降低,使鋅浴在較小的過冷度下發(fā)生結(jié)晶形核,隨著鋁含量的增加過冷度依次降低,稀土比同等含量的鋁更能降低鋅浴的過冷度。表面張力隨鋅浴的溫度的升高而降低;同等溫度下,鋅浴的表面張力比真空狀態(tài)下小。少量的鋁和稀土均可以降低鋅浴的表面張力。鋅浴的流動(dòng)性隨著溫度的升高而增強(qiáng),少量的鋁元素可以降低鋅浴的流動(dòng)性,少量的稀土可以改善鋅浴的流動(dòng)性能,純鋅浴的流動(dòng)性能最好,在430～520℃間,流動(dòng)長度為36.9～49.1cm。
[Abstract]:Hot dip galvanizing technology has been invented for more than 300 years and is still the most effective method for iron and steel protection. Most of the studies on hot dip galvanizing are focused on the microstructure and corrosion resistance of the coating, but there are few studies on zinc bath which has important influence on the coating. Based on the national fund project "study on the characteristics of zinc bath and pre-control of coating properties", this paper studies the crystallization characteristics, surface tension and fluidity of zinc bath, which provides the theoretical basis for the establishment of pre-evaluation model of zinc bath liquid properties. In this paper, we have prepared the Zn / Zn ~ (0. 05) / Al ~ (2 +) Zn ~ (0. 5) and Al ~ (2 +) Zn ~ (0. 3) and Al ~ (2 +) Zn ~ (0. 2) Al ~ (2 +) Zn ~ (2 +) ~ (0. 2) Al ~ (2 +) Zn ~ (0. 3RE) alloy. The complete cooling curves of zinc and alloy zinc bath at 430 鈩，

本文編號(hào)：2160987