What are the impacts of excessively long drying time for steel pipes?

When steel pipes coated with solvent are dried in a drying oven, excessively long drying time can have two implications: one is excessively long drying at a higher temperature, and the other is excessively long drying at a lower temperature. If the drying time is too long at a higher temperature, it will cause the solvent to be overheated, resulting in burning and yellowing on the surface of the steel pipe. Such a solvent loses its galvanizing-assisting effect and leads to missed galvanizing. On the other hand, if the drying time is too long at a lower temperature, the moisture in the solvent cannot evaporate quickly. As the moisture concentrates towards the ends of the steel pipe holes, it will remain on the inner walls of the holes at both ends, diluting the solvent components and creating favorable conditions for oxidation. This can result in missed galvanizing on the inner wall surfaces of the holes at both ends and the occurrence of "explosion" during immersion galvanizing.