Why do steel pipes need to be pickled, degreased, and passivated

Mainly for steel pipelines, which are prone to corrosion reactions and may cause damage to equipment after corrosion. After removing all kinds of oil stains, rust, oxide scale, weld spots, and other dirt, the corrosion resistance of steel can be greatly improved.

If there is dirt on the surface of the stainless steel pipe, it should be cleaned mechanically and then deoiled and degreased. The presence of grease on the surface will affect the quality of pickling and passivation. Therefore, degreasing and degreasing cannot be omitted. Alkali, emulsifier, organic solvent, and steam can be used. Wait for it to proceed.

Passivation is the last process step in chemical cleaning and is a critical step. Its purpose is to prevent corrosion of materials. For example, after a boiler has been pickled, washed with water, and rinsed, the metal surface is very clean, very activated, and prone to corrosion. Therefore, passivation treatment must be carried out immediately to form a protective film on the cleaned metal surface to slow down corrosion.