A Study of Zn-coating Weight in Hotdip Galvanizing Process

응용아연(응용亞鉛) 도금공정(鍍金工程)에서 아연부착량(亞鉛附着量)에 관한 연구

This experiment intends to study Zn-coating weight through galvanixing process. A through examination has been carried out on the change of steel-composition, galvanizing-temperature, dipping-rime, Fe-loss when other factors were regular. Activation energy needed for Fe-loss was obtained and within this sample, the best condition which has influence on coating weight was found so as to reduce Fe-loss. As Fe-loss was diminidhed, the amount of product of Dross and Zn-using amount per total products could be reduced. The results of experiments are as follow. 1. Zn-coating thickness was increased by the rising Zn-bathtemperature and was the maximum at 8-minutes dipping time. 2. The coating weight was greatly influency by Si. As in other samples, the proportion of increasing was very rate after 20minutes. If the dipping time prolonged, the increasing amounts of Fe-loss are more greatly. 3. Activation Energy needed for Fe-loss was as follows Such numerical values were most equal to those of the activation energy which had influences on the growth of ${\gamma}$-phase. Sample - I = 18,500 Cal/mole Sample - III = 22,000 Cal/mole Sample - V = 42,300 Cal/mole

本 실험에서는 熔融亞鍍金工程에서 다른 諸要因을 一定하게 하고 鋼金溫度와 浸積時間에 따른 亞鉛附着量과 銑損失을 組織학的인 면에서 考察하였다. 銑損失에 要하는 活性化에너지를 구하였으며 試料範위內에서 附着量에 미치는 최적조건을 찾으므로서 不당한 銑損失을 막고 亞鉛原단位를 줄이는데 目的이 있다. 銑損失量과 드로스(Dross)발생량이 상호 密接한 關係에 있으며 도로스 발생량이 감소되면 亞鉛原단位가 감소되었다. 실驗結論은 다음과 같다. 1. 同一時間內에서 詩片-I은 470$^{\circ}$까지 도금층 두께 형성이 온도에 비례하며 浸積時間 8分정도에서 最大값을 나타낸다. 2. 詩片-5는 浸積時間에 比例해서 附着量이 급증함을 나타내었는데 이는 Si의 영향이 지배적이며 그 이외의 試料에서는 20分이후 附着量增加率이 극히 적었다. 浸積時間은 20分이 가장 적당하며 더 이상 오해 浸積시키면, 銑損失量만, 증가할 것이다. 3. 銑損失에 要하는 活性化에너지는 다음과 같으며 이와같은 값은 ${\gamma}$相의 成長에 미치는 活性化에너지 값과 거의 비슷하리라 생각됨. 詩片 - I = 18,500 Cal/mole 詩片 - III = 22,000 Cal/mole 詩片 - V = 42,300 Cal/mole