Some doubts about bearing and bearing steel rust (1)

Update:02-12-2021
Summary:

Question 1: Will bearing steel rust?
Will rust. Bearing steel, including stainless steel, is rusty.
Although stainless steel is said to be stainless, it is actually rusty. In fact, there is no rust-free steel in the world!
Question 2: How does the bearing steel rust?
The so-called stainless steel refers to different degrees of corrosion resistance.
Corrosion rate <0.01mm/y, considered as "complete corrosion resistance";
If the corrosion rate is less than 0.1mm/y, it is considered "corrosion resistant";
If the corrosion rate is greater than 0.1mm/y, it is considered "not corrosion resistant", that is, ordinary steel.
Except for a small part of the bearing steel is stainless bearing steel, most of it is ordinary corrosion-resistant steel, so it is not strange at all to rust, it is normal.
Question 3: Why does the bearing rust?
Bearing rust is related to the material and use environment. The bearing steel itself contains carbon and will react with moisture. If you want to prevent the bearing from rusting, you must do a good job of anti-rust treatment. Or choose non-steel bearings.
Metal products are prone to rust after oxidation, and stainless steel bearings are no exception. There are many factors that affect its rust: such as the chemical composition and structure of the metal material itself; the surface finish (corrosion of the battery with poor oxygen concentration); the composition and pH value of the solution in contact with the metal surface; and the environment in which it is located. All are the direct factors that make the bearing rusty.
In addition, when we use bearings, do not directly touch objects with your hands, because when sweat contacts the bearing, it will form a layer of sweat film on the bearing surface, which will cause electrochemical effects on the bearing and corrode the bearing. Therefore, we must use special gloves or finger cots and other special tools to pick up the bearing, and don't touch it directly with your hands.