Can weathering steel plate be rusted with phosphating agent?

Common weather-resistant steel plate materials include Corten A, Corten B, etc., which have good corrosion resistance and oxidation resistance. Phosphating is a commonly used surface treatment method, mainly for rust prevention and increased coating adhesion.
For weather-resistant steel plates, their own oxide layer is usually used as a protective layer, and surface treatment such as phosphating is not required for rust prevention. Therefore, in most cases, phosphating is not recommended for weathering steel sheets.
In particular, since the phosphating process requires the use of acidic solutions, this may damage the oxide layer of the weathering steel plate itself, thereby affecting its corrosion resistance and oxidation resistance. Therefore, when considering whether to carry out surface treatment on weathering steel plates, you should fully understand its material characteristics, and refer to relevant standards and recommendations for operation.