Knowledge

14Nov, 2024

Why is it necessary to control the concentration of passivation solution?
As mentioned earlier, the normal passivation film on the galvanized surface of galvanized steel pipes is generally yellow. However, after batches of galvanized steel pipes are cool
13Nov, 2024

Why is the temperature of the chromate passivation solution strictly controlled?
When galvanized steel pipes undergo passivation treatment in a passivation solution, the temperature of the chromate passivation solution used should be strictly controlled below 5
13Nov, 2024

Why are there several colors of passivation films, and what color is the pass...
The color of the passivation film primarily varies with the content of hexavalent chromium and the thickness of the film. When the concentration of hexavalent chromium is high, the
13Nov, 2024

What are the properties of the passivation film?
The thickness of the passivation film generally ranges from 0.5 to 1 micrometer (μ). It is very stable in nature, with a fine and dense structure, exhibiting a transparent metal
13Nov, 2024

What are the components of the passivation film that provide corrosion protec...
Analysis of the passivation film reveals that it primarily contains trivalent chromium, followed by water, hexavalent chromium, and other components such as sulfate, zinc, and sodi
13Nov, 2024

Why are acids added to some chromate and chromic acid passivation solutions? ...
In some passivation solution formulations, acids such as nitric acid, sulfuric acid, phosphoric acid, and acetic acid are added. The advantages include: facilitating the dissolutio
12Nov, 2024

Formula for Chromate Purification Solution
The most representative formula for chromate passivation solution has been in use for over two decades. After such a long period of testing, it has proven to be practical and feasi
12Nov, 2024

What are the methods of surface passivation treatment, and which one is the m...
In the production of galvanized steel pipes, the main passivation treatment methods currently applied worldwide are chromate passivation and phosphating treatment. The former is pr
12Nov, 2024

Why is surface passivation treatment necessary for galvanized coatings?
(1) To improve the structural composition and gloss of the galvanized coating's surface. (2) To enhance the corrosion resistance and service life of the galvanized coating. (3)
12Nov, 2024

What is passivation and how is it defined?
When a piece of iron is placed in a diluted nitric acid solution, it will vigorously dissolve and emit red fumes, which indicates corrosion of the iron. However, if concentrated ni
12Nov, 2024

Why should the water droplets inside and outside the cooled galvanized steel ...
Because after removing the galvanized steel pipe from the cooling water, it still needs to undergo passivation treatment. If the cooling water attached to the inner and outer surfa
11Nov, 2024

Why do galvanized steel pipes sometimes develop visible turtle cracking on th...
The reason for the appearance of turtle cracking on galvanized steel pipes after water cooling is primarily due to the pipes not undergoing sufficient air cooling, resulting in a r

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