中文摘要：

根据对Zr-Fe-Si三元体系的热力学评估计算和实验研究，体系中Si的化学位随Zn含量的增加而迅速提高．通过高温镀锌实验分析了difruse—△（δ相＋锌液）区域形成的原因，阐述了热浸镀锌中硅反应性的机理．镀层中的Si有向Fe含量高的相（特别是δ／ζ相界附近的δ相）、δ／ζ相界及ζ相晶界富集的趋势．随时间推移，扩散通道向富Si端移动，切过ζ相与液相两相平衡的共轭线，导致ζ相晶界附近出现的液体容纳Si，形成液体通道，液相穿过ζ相并与外面的锌液连接．液体直接与δ相接触，导致微应力的出现，液体可以沿着微裂纹腐蚀δ相，形成破碎的difruse—△区域，锌液直接侵蚀基体．镀层生长受界面反应控制，镀层的线性生长导致形成较厚的镀层．

英文摘要：

According to the thermodynamic calculation of Zn- Fe-Si ternary system and the experimental investigation, the chemical potential of Si increases greatly with the increase in Zn content. By high temperature galvanizing experiments, the form reason for diffuse A （δ ＋ liquid） was analyzed and the mechanism of silicon reactivity was explained. Si in coating trended to gather in the phases with high Fe content such as δ phase near δ/ζ phase boundaries, phase boundaries of δ/ζ layers, and grain boundaries of ζ phase. In galvanizing, the diffusion path in coating moved to the Si rich side, cut the tie-line of （ζ ＋ liquid） phases equilibrium, and led the liquid phase to appear at ζ phase boundaries and to accommodate silicon. Liquid channels formed as the liquid phase crossed ζ layers and connected with the outside liquid. Therefore, the liquid channels contacted with δ phase directly and the micro stress was produced at the meantime, and then the liquid eroded δ phase along the microcracks as well as the diffuse A （cracked δ ＋ liquid） region formed, the liquid attacked the substrate directly. The growth of coatings was controlled by interracial reaction, and the thickness of coatings increased linearly.