Brief description of "handprint corrosion" of titanium and titanium alloys

When we were manufacturing titanium and titanium alloy products with high surface requirements, we discovered an interesting phenomenon.

If you touch the freshly processed titanium and titanium alloy products with your bare hands, you will leave a distinct yellow fingerprint on the surface of the products.

A seemingly ordinary action in daily life - directly touching the surface of titanium and titanium alloy products with your hands - could potentially become the trigger for rust formation. This corrosion phenomenon caused by fingerprint residues is called "handprint corrosion".

Let's analyze the composition of sweat. Sweat is mainly composed of water, salt, and a small amount of organic substances. Among them, the salt mainly exists in the form of sodium chloride. Although sodium chloride itself has a relatively weak corrosive effect on titanium alloys.

However, under certain conditions, such as in high-temperature and high-humidity environments, and when the titanium products have already undergone processing (with no oxide layer formed on the surface), the salt content in sweat may accelerate the corrosion process of the titanium alloy. Moreover, the organic substances in sweat may also react chemically with the titanium alloy, thereby affecting the surface quality of the titanium products.

Prevention methods for handprint corrosion:
Cleaning: Immediately wipe with a non-woven cloth dipped in industrial alcohol after contact. Or rinse thoroughly with plenty of water and then wipe to remove any fingerprint residues. Avoid bare-hand contact: During operation, wear nitrile gloves. The gloves should be changed regularly (it is recommended to replace them every 2 hours) .

In conclusion, although the corrosiveness of sweat to titanium alloys is relatively weak, under certain conditions, the components in sweat may have a certain corrosive effect on titanium alloys. Therefore, when manufacturing titanium alloy products, especially in high-temperature and high-humidity environments, it is necessary to pay attention to wearing protective equipment and reducing bare-hand contact with the product surface. This is to avoid the problem of "handprint corrosion".