Attaching a magnet to a refrigerator typically will not cause the refrigerator to rust. Magnets themselves do not induce rust on metal surfaces. Rusting occurs when metal, such as iron or steel, reacts with oxygen and water in the presence of certain environmental conditions.
Refrigerators are usually made from stainless steel, which contains chromium, an alloying element that helps provide resistance to corrosion, including rust. Stainless steel is chosen for appliances like refrigerators because of its ability to withstand moisture and other environmental factors.
As long as the surface of the refrigerator remains intact and is not scratched or damaged by the magnet's attachment, there should be no significant risk of rust forming due to the magnet alone. However, if the refrigerator's surface is scratched or damaged and exposes the underlying metal, it might be more susceptible to rusting over time.
To ensure the longevity of your refrigerator and to prevent potential rusting issues, it's essential to clean and maintain the surface regularly, keeping it dry and free from any damage that could compromise its protective layer.