Brief description of "fingerprint corrosion" in titanium and titanium alloys

When producing titanium and titanium alloy products with high surface requirements, we observed an interesting phenomenon.

Touching freshly processed titanium and titanium alloy products with bare hands will leave a distinct yellow fingerprint on the surface.

A seemingly ordinary daily action—directly touching the surface of titanium or titanium alloy products with bare hands—can actually become a trigger for corrosion. This type of corrosion caused by fingerprint residue is known as "fingerprint corrosion."

Let's analyze the composition of sweat. Sweat is primarily composed of water, salts, and a small amount of organic substances. Among these, the salts mainly exist in the form of sodium chloride. Although sodium chloride itself has relatively weak corrosive effects on titanium alloys.

However, under certain conditions—such as high temperature and high humidity—and when titanium products have already been processed (without an oxide layer formed on the surface), the salts in sweat may accelerate the corrosion of titanium alloys. Additionally, organic compounds in sweat can chemically react with titanium alloys, thereby affecting the surface appearance of titanium products.

Prevention methods for fingerprint corrosion:
Clean: Wipe immediately with a non-woven cloth dampened with industrial alcohol after contact. Alternatively, rinse thoroughly with plenty of water and wipe to remove fingerprint residue.

Avoid direct hand contact: Wear nitrile gloves during operation, and replace them regularly (recommended every 2 hours).

In summary, although sweat itself has relatively low corrosiveness toward titanium alloys, under certain conditions, the components in sweat may still cause some degree of corrosion. Therefore, during the manufacturing of titanium alloy products—especially in high-temperature and high-humidity environments—it is important to wear protective gear and minimize direct hand contact with product surfaces to prevent "fingerprint corrosion."