Key Considerations for Selecting Titanium Tubes: Checking Surface Treatment Process for Corrosion Resistance

In the selection and application of titanium tubes, the surface treatment process is a crucial factor affecting their corrosion resistance. Although titanium tubes inherently possess a certain degree of corrosion resistance, the surface may retain rolling scale, oil stains, or minor scratches after manufacturing. These defects can damage the natural oxide film on the titanium tube surface, increasing the risk of localized corrosion, especially in harsh corrosive environments such as strong acids and bases. Therefore, checking the surface treatment process of titanium tubes is essential.  Acid pickling and passivation treatment can further enhance corrosion resistance.  Confirming the quality of this treatment is a critical step in ensuring the stable operation and extended service life of titanium tubes in corrosive conditions, and is a core consideration in titanium tube selection.

Acid pickling and passivation treatment optimizes the surface condition of titanium tubes through chemical action, significantly enhancing corrosion resistance. This process typically consists of two steps: acid pickling and passivation. The acid pickling stage uses a mixed solution of dilute nitric acid and hydrofluoric acid to remove oxide scale, rust, and oil stains from the titanium tube surface, eliminating surface defects. The passivation stage uses a strong oxidizing solution (such as concentrated nitric acid) to promote the formation of a denser and more stable oxide film (titanium dioxide film) on the titanium tube surface. This reinforced oxide film can more effectively block the penetration of corrosive media, reducing the risk of localized corrosion (such as pitting and crevice corrosion). For example, in sulfuric acid transportation pipelines in the chemical industry, untreated titanium tubes with residual oxide scale are prone to pitting corrosion, resulting in a service life of only 3-5 years; while titanium tubes that have undergone proper acid pickling and passivation have a complete and uniform surface oxide film, effectively resisting sulfuric acid corrosion, extending the service life to 8-10 years, and reducing the risk of media contamination caused by corrosion. 3 Inch Titanium Pipe / Gr1 Pure Titanium Pipe / Grade 3 Pure Titanium Pipe / ams 4944 seamless pipe

Confirming the quality of titanium tube acid pickling and passivation treatment requires a comprehensive assessment from both appearance and inspection reports. High-quality pickled and passivated titanium tubes should have a uniform silver-white or grayish-white surface, free from noticeable color differences, spots, residual stains, or scratches, and feel smooth to the touch.  If the surface appears yellowish, blackened, or shows localized discoloration, it may indicate incomplete pickling or uneven passivation film formation, which will affect corrosion resistance. Furthermore, manufacturers should provide a pickling and passivation test report, clearly stating the processing parameters (such as acid concentration, treatment temperature, and time), passivation film thickness test data (usually required to be ≥50nm), and salt spray test results (e.g., 48 hours of neutral salt spray test without corrosion). For example, when a marine engineering company purchased titanium tubes, they found yellowish marks on the surface of some tubes during visual inspection.  Combined with the "insufficient passivation time" record in the test report, they promptly returned the defective products, preventing subsequent rapid corrosion of the titanium tubes in the seawater environment due to passivation film defects.

In summary, checking the surface treatment process of titanium tubes, especially confirming the quality of pickling and passivation treatment, is a crucial step in ensuring their corrosion resistance. When purchasing, first observe whether the surface appearance of the titanium tubes meets the standards, then request and verify the pickling and passivation test report to ensure that the treatment process is standardized and the quality meets the requirements. For titanium tubes used in highly corrosive conditions, sampling salt spray tests or re-testing of passivation film thickness can be requested to further verify the treatment effect. By strictly controlling the surface treatment quality, titanium tubes can fully utilize their corrosion resistance advantages, providing reliable protection for the safe operation of industrial pipeline systems in corrosive environments.