61. How do aluminum-zinc-containing and aluminum-zinc-free liquids differ in their corrosion effects on iron?

When steel pipes are immersed in zinc for a short duration, the corrosion rate in aluminum-free galvanized pots is approximately 7-9 times faster than that in aluminum-containing galvanized pots. However, when the zinc immersion time exceeds 8 minutes, the corrosion rate in aluminum-containing galvanized pots becomes higher than that in aluminum-free ones. While the former is advantageous for rapid zinc immersion to boost production efficiency, the latter can adversely affect the galvanized pots. In practical applications of aluminum-containing galvanized pots, it has been observed that the corrosion pits formed on the galvanized steel plates at the zinc liquid level are significantly deeper.