【摘要】 热浸镀锌中锌浴的结晶特征会对镀层的质量和性能产生重要影响,因此,研究热浸镀锌浴的结晶特征具有重要意义。研究了浇注温度在430～520℃范围内一些锌浴的结晶特征,并分析了这些锌浴结晶特征对锌浴凝固组织的影响。结果表明,Zn、Zn-0.05Al、Zn-0.1Al、Zn-0.2Al、Zn-0.3Al、Zn-0.5Al、Zn-0.2Al-0.2Re和Zn-0.2Al-0.3Re的过冷度范围分别为1.8～5.6℃、1.4～5℃、1.3～4.6℃、1.4～4.1℃、1.3～3.3℃、0.9～2.7℃、1.9～3.2℃和0.9～3℃;在锌浴成分一定的条件下,温度越高,过冷度越小;而在温度一定的条件下,异质元素Al、稀土(Re)的含量增加会导致过冷度减小。在450℃时,与纯锌相比,Zn-0.05Al和Zn-0.1Al的晶粒更粗大,主要受到温度过冷的控制;随着Al含量的增加,ZnAl的过冷度减小,晶粒变细,这是铝含量增加导致成分过冷的结果。在0.2%锌铝浴中添加Re,进一步加强了异质形核,导致成分过冷,使得Zn-0.2Al-0.3Re的晶粒比Zn-0.2Al-0.2Re更细小。更多还原

【Abstract】 The crystallization characteristics of zinc bath in hot-dip galvanizing have a significant impact on the quality and performance of the coating. Therefore, studying the crystallization characteristics of hot-dip galvanizing bath is of great significance. The crystallization characteristics of some zinc baths in the pouring temperature range of 430-520 ℃ was studied, and the influence of these zinc bath crystallization characteristics on the solidification structure of the zinc bath was analyzed. The results show that the undercooling ranges of Zn, Zn-0. 05Al, Zn-0. 1Al, Zn-0. 2Al, Zn-0. 3Al, Zn-0. 5Al, Zn-0. 2Al-0. 2Re, and Zn-0. 2Al-0. 3Re are 1. 8-5. 6 ℃, 1. 4-5 ℃, 1. 3-4. 6 ℃, 1. 4-4. 1 ℃, 1. 3-3. 3 ℃, 0. 9-2. 7 ℃, 1. 9-3. 2 ℃, and 0. 9-3 ℃, respectively. Under the condition that zinc bath composition is certain, the higher the temperature, the lower the undercooling. Under certain temperature conditions, an increase in the content of heterogeneous elements Al and rare earth(Re) will lead to a decrease in undercooling. At 450 ℃, compared with pure zinc, the grains of Zn-0. 05Al and Zn-0. 1Al are coarser and mainly controlled by temperature undercooling. As the Al content increases, the undercooling of Zn Al decreases and the grains become finer, which is the result of the increase in aluminum content that leads to composition undercooling. Adding Re to a 0. 2% zinc-aluminum bath further enhances heterogeneous nucleation, leading to composition undercooling and finer grains of Zn-0. 2Al-0. 3Re compared to Zn-0. 2Al-0. 2Re.更多还原