Passivation of seamless stainless steel pipes is a metal treatment process designed to protect the substrate from oxidative corrosion by forming a stable passivation film on the metal surface. This treatment is especially effective for stainless steel pipes. By reacting with the passivating agent, a dense film forms on the surface of the stainless steel, providing excellent coverage and effectively preventing direct contact between the metal and corrosive media, thus achieving corrosion prevention. The primary tool for implementing this technology is stainless steel passivation liquid, which has the following characteristics and advantages.
Characteristics and Advantages
- Wide Applicability:
Suitable for all stainless steel products of the SUS200, SUS300, and SUS400 series.
- Ease of Operation:
Simple to use—stainless steel products can be soaked in the passivation liquid without the need for special processing equipment or strict additional conditions, effectively reducing costs.
- Significantly Improved Corrosion Resistance:
According to ASTM B-117 and DIN EN ISO 9227 neutral salt spray test standards, corrosion resistance is increased by 5 to 20 times. One liter of passivation solution can treat about 60 square meters of stainless steel surface.
- High Stability:
The passivation liquid is a stable agent that does not decompose or precipitate, making it easy to transport and store for long periods.
- Wide Application:
Widely used in industries such as aerospace, mobile communications, eyewear, watches, and auto parts.
General Steps and Methods for Passivation Treatment
- Mechanical Treatment:
Ensure the pipe surface is clean and free of impurities by removing surface dirt and oxides through grinding, sandblasting, etc.
- Pickling Treatment:
Use strong acid solutions such as dilute sulfuric acid or dilute hydrochloric acid to clean surface oxides and impurities, promoting the formation of a passivation film.
- Chemical Treatment:
Form a protective passivation film on the surface through soaking or spraying methods.
- Electrochemical Treatment:
Utilize electrochemical principles to form a dense oxide film on the surface of stainless steel through methods such as anode protection and anode passivation.
Choosing the appropriate treatment method is crucial to ensuring good passivation results. For instance, after pickling and passivating SS316 stainless steel pipes, their corrosion resistance is significantly improved, making them especially suitable for environments with high chloride ion concentrations.
When performing passivation treatment, it is essential to select the appropriate methods according to different situations and ensure the treatment process is standardized to achieve good passivation effects. Additionally, protective measures should be taken after passivation treatment to extend the service life of stainless steel pipes.
United Steel Industry As the most important steel pipe manufacturer and exporter in China, in the past 20 years, we have completed more than 100 projects, with partners in more than 100 countries, and established relationships with oil and gas and EPC companies in many countries business relationship.
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please consult:Email:Sales@usisteels.com
