Have you ever had a kitchen knife rusted?
There are various causes for rusting kitchen knives.
Once rusted, it is troublesome to remove the rust, so let’s understand the cause of rusting the kitchen knife.
What causes kitchen knives to rust?
Let’s take a quick look at what causes kitchen knives to rust.
The mechanism until the kitchen knife rusts is as follows.
- Water gets on the knife blade
- A thin film of water is formed on the surface of the blade
- Oxygen in the air dissolves in the water film
- The dissolved oxygen and the knife blade cause a chemical reaction
- Rust (iron oxide) is generated
In other words, if the knife is covered with water, it will easily rust. The chemical reaction between oxygen and iron is the cause of rust, and water supports this reaction.
【Point】：Rust on kitchen knives is caused by “moisture” attached to kitchen knives and “oxygen” in the air. Oxygen dissolves in the water adhering to the blade, and the oxygen and iron cause a chemical reaction to generate rust (iron oxide).
Is it natural for the metal to rust?
In fact, many metals are excavated in a rusted state, but as you can see from this, metal has the property of trying to rust itself if left alone.
Of course, the knife blade is the same. Regardless of whether the product is good or bad, it is natural that it will rust if it is not properly maintained.
If you know this as a major premise, the handling of kitchen knives will change.
NG action that accelerates rust on kitchen knives
In addition, it may promote rusting of kitchen knives. It is dirt on the surface of the blade. If the kitchen knife is dirty, the film made of water will change to acidic and cause rusting to be promoted. In short, it’s dangerous to leave it unwashed after using the kitchen knife.
Wash and Wipe dry the knife immediately after use. If you follow this rule, you will not have to worry about rusting.
rust-easy knives and rust-resistant knives
Also, how the kitchen knife rusts depend on the type of kitchen knife you are using.
Steel knives are easy to rust, and stainless steel knives are hard to rust.
- Steel knives ・ ・ ・ Easy to rust
- Stainless steel kitchen knife ・ ・ ・ Rust resistant
Stainless steel is unlikely to rust badly if left in water, but steel knives will rust if you take your eyes off for tens of minutes.
Stainless is not equal to never rust
By the way, the reason why stainless steel is hard to rust is as follows.
When “chromium” contained in stainless steel combines with oxygen in the air, a thin oxide film is formed on the surface of the knife blade. This makes the inside of the kitchen knife less likely to rust than other materials.
By being protected by an oxide film, stainless steel knives are less likely to rust.
Strictly speaking, this film is also rusty, but thanks to the oxide film that is formed, it does not erode further inside.
If there is a film on the surface of the blade, rust can be prevented.
Rust can be prevented if there is a film on the surface of the knife blade, like the oxide film that can be made of stainless steel.
From this idea, applying vegetable oil to the surface of the blade is also considered to be an effective means of preventing rust.
It is recommended to apply a thin coat of maintenance oil or salad oil for cutlery during storage as it will prevent rusting.
If you know the cause of rust and how to prevent it, you can use the kitchen knife for a longer time. Be especially careful if you bought a good knife.
