Among many metallic materials, stainless steel is widely used in modern industry and construction due to its excellent corrosion resistance, high strength and cleanliness and hygiene properties. However, even stainless steel may be subject to corrosion under certain conditions. In order to further improve the corrosion resistance of stainless steel, pickling passivation process technology came into being, especially for thin-walled stainless steel pipe and fittings surface treatment.
Pickling passivation is a chemical surface treatment process, it is through the removal of stainless steel surface oxidation layer, corrosion, welding slag and other impurities, while the formation of a thin and dense layer of oxidized film on the surface (Cr2O3), that is, passivation film. This passivation film can effectively isolate the metal matrix and external corrosive media contact, significantly improve the corrosion resistance and service life of the material.
For thin-walled stainless steel pipe and fittings, pickling passivation process is particularly important. Thin-walled materials due to small wall thickness, the resistance to corrosion and wear is relatively weak. Through pickling passivation treatment, not only can improve the corrosion resistance of the material, but also improve its surface finish. Extend the service life of the pipeline.
Pickling passivation process usually includes the following steps:
First, the upper hanging is put into the alkaline washing tank, and the surface of stainless steel pipes and fittings is cleaned by ultrasonic using alkaline solution to remove grease and other impurities;
Secondly, then use 3 water washing to clean the surface of stainless steel pipe and fittings;
Next, the use of pickling passivation solution for surface treatment of stainless steel pipes and fittings, through the chemical reaction, the formation of Cr2O3 passivation film on the surface of stainless steel pipes and fittings;
Next, 4 washing treatment to remove the residual acidic substances on the surface of stainless steel pipes and fittings to ensure surface cleanliness;
Then, air-drying treatment, so that the surface of stainless steel pipes and fittings dry.
Finally, hang down to enter the next process.
The application of this process technology not only improves the quality and performance of stainless steel pipes and fittings, but also brings significant economic and environmental benefits to related industries. By improving corrosion resistance, the service life of the product is extended, and the frequency of replacement and maintenance costs are reduced. At the same time, the passivation film formed during the pickling passivation process is environmentally friendly and does not pollute the environment.
However, there are some challenges associated with the pickling passivation process. For example, the concentration of the pickling solution and the treatment time need to be precisely controlled to prevent excessive corrosion; at the same time, the treated waste solution needs to be treated with effluent to avoid impacting the environment.
In summary, pickling passivation process technology plays a key role in improving the corrosion resistance of thin-walled stainless steel pipes and fittings. With the continuous development and improvement of the technology, we expect this process to provide high-quality stainless steel products for more industries in the future.
