The passivation temperature after galvanizing is generally 20℃-40℃, and the passivation time is 5-20 minutes. These parameters can ensure that the galvanized layer forms a dense passivation film and improves corrosion resistance. The specific temperature and time may be adjusted according to the coating type and standard.
Author: Marisa
The passivation temperature after galvanizing is generally 20℃-40℃, and the passivation time is 5-20 minutes. These parameters can ensure that the galvanized layer forms a dense passivation film and improves corrosion resistance. The specific temperature and time may be adjusted according to the coating type and standard.
Galvanizing is a common metal anti-corrosion treatment method that protects the substrate from corrosion by covering the steel surface with a layer of zinc. However, galvanizing alone is not enough to provide long-term anti-corrosion effects, and passivation treatment is also required. Passivation refers to the formation of a dense chemical conversion film on the surface of the galvanized layer to further improve its corrosion resistance.
1. Passivation temperature after galvanizing
The passivation temperature after galvanizing is one of the important factors affecting the quality of the passivation film. Generally speaking, it is more appropriate to control the passivation temperature between 20℃-40℃. Within this temperature range, the chemical components in the passivation solution can fully react with the galvanized layer to form a uniform and dense passivation film. If the temperature is too low, the reaction speed slows down, which may lead to incomplete formation of the passivation film; if the temperature is too high, the passivation film may become loose and reduce its anti-corrosion effect.
2. Passivation time after galvanizing
In addition to temperature, passivation time is also a key factor in determining the quality of the passivation film. Usually, the passivation time is controlled between 5-20 minutes. During this period of time, the chemical components in the passivation solution have enough time to react with the galvanized layer to ensure that the passivation film can completely cover the surface of the galvanized layer. Too short a passivation time may result in insufficient thickness of the passivation film and reduced anti-corrosion performance; while too long a time may cause unnecessary waste of resources and even have an adverse effect on the galvanized layer.
3. Other factors affecting the passivation effect
In addition to temperature and time, there are some other factors that affect the passivation effect after galvanizing. For example, the proportion and pH value of the passivation solution need to be controlled within a certain range. Generally speaking, the proportion of the passivation solution should be controlled between 8%-10% to ensure that the workpiece can obtain a bright color appearance. At the same time, the pH value of the passivation solution should also be maintained at an appropriate level, usually between 1.8-3.5. The reasonable adjustment of these parameters helps to improve the quality and stability of the passivation film.
In summary, the passivation temperature and time after galvanizing are crucial to ensure the anti-corrosion performance of the galvanized layer. By reasonably controlling these parameters and other influencing factors, a uniform, dense and corrosion-resistant passivation film can be obtained.