Cause analysis of corrosion of miniature linear guide
After the miniature linear guide is corroded, s is found in the oil stains and the corroded micropits of the chute. The residual s content in the chute pits after being briefly cleaned by "ethanol + ultrasonic" is almost twice that of the oil. One possible explanation is that the guide rail oil anti-wear agent s is easy to absorb water molecules in the air and then hydrolyze to become acidic. Because the specific gravity is higher than that of oil, it will be deposited on the bottom of the chute, bound to the rough surface of the pits, and aggravate surface corrosion. The evaporation of water in cutting fluid is also an important source of water molecules in the air. The most common form of S in micropits is in the form of sulfates such as potassium sulfate and calcium sulfate.
A small amount of metal chips adhering to the slider can be generated by scraping from the track surface, and a large amount of metal chips comes from the chip breaking pollution generated during the metal processing. Metal chip breaking is stuck with cutting fluid. When the cutting fluid is mixed with the guide oil, it will form an oil-water mixture, that is, sludge. On the other hand, the anti-rust components such as alkali in the cutting fluid are easily absorbed by the oil, and the remaining water is heavier than the oil, sinking to the bottom of the chute, and is more likely to be bound to the damaged surface, accelerating the corrosion of the rail surface.
Corrosion occurs first in the damaged micropit, and then expands to the bottom and wall of the pit, and the corrosion area continues to expand. The corrosion liquid spreads, mixes with grease, pollutes the grease, and the rust prevention ability of the area spread by the corrosion liquid is weakened.