Even stainless steel knives rust.

We regularly hold knife sharpening classes at our company, and
We take advantage of the time we have to let the whetstone absorb water before we start the practical skills.
We give a lecture on the basic knowledge of the whetstone and kitchen knives.

At that time, we also explain about “Hagane (carbon steel)” and “Stainless steel”.
Hagane” is a highly pure iron that contains about 1% carbon.
It is a metal that is hardened by heating it to about 800°C (1000°C for stainless steel) and then quenching it with oil or water.

“Stainless steel” is similarly hardened by carbon,
It is a steel that contains more than 15% of a rare metal called chromium.

Chromium is an excellent material that reacts quickly with oxygen and moisture in the air,
It reacts quickly with oxygen and moisture in the air to form a transparent film that is invisible to the human eye.

As a result, the steel is sealed off from the air and rust does not occur.
“Stainless steel” is the general term.

Therefore, since the main ingredient is still iron, the term “stainless steel”
If left unattended with acids or salts, rust will occur.

Even stainless steel knives should be washed clean after use.
Remember to wipe it off with a dry towel or the like after use.

*This is a translation by a translation tool.