#erklärmir: Can Stainless steel rust?

As part of our little mini-series #erklärmir, this time we talked to industrial engineer Christian Hajicek about the exciting topic of “Stainless steel” in all its facets. What is the difference between chromium steel and chromium-nickel steel? Can stainless steel rust? And how do you look after stainless steel properly?

On the trail of rust

This edition of the series deals with the relatively unpopular topic of rust. KUNe Stainless steel Utility Sinks are made of chromium-nickel steel (1.4301), one of the most popular stainless steels. We get to the bottom of the question of whether stainless steels can also be affected by rust stains, what could be the reason for this and how rust can be prevented. We asked the metallurgist Dipl.-Wirt.-Ing. Hajicek.

Mr. Hajicek, in general: Can Stainless steel rust?

Yes, if it is processed and finished incorrectly, rust can form on the surface. First and foremost, however, you should be careful with the term Stainless steel in connection with this topic. There are a lot of Stainless steels that are not necessarily rust and acid resistant. When we talk about Stainless steel in this interview today, we are talking about the so-called “stainless steel” that is also used for your basins.

Chromium-nickel steel with the number 1.4301 is one of the most important stainless steels, if not the most important.

What is the chemical process behind rusting?

The rusting process is a combination of atmospheric oxygen and moisture. This interaction ultimately leads to the formation of rust.

Why doesn’t “Stainless steel” rust?

The special feature of stainless steel is that the chromium (12 % should be contained in the material) forms a so-called Passive Film with the oxygen in the air, which means that rust attack in the classic sense is not possible.

If this protective layer has been damaged, can it rebuild itself?

That is the pleasant thing about Stainless steel. After mechanical damage, the layer heals. The oxygen in the air stimulates the free steel surface to build up an oxide layer. This is known as a self-healing effect.

After mechanical damage, the Passive Film heals. This is referred to as a self-healing effect.

Find out more about the material now

However, contact corrosion can also cause rust stains on stainless steels. What is this all about?

Yes, contact corrosion is a problem. This occurs when so-called Black material, i.e. ordinary carbon steel, penetrates a sink. The less noble material, such as grinding residue or similar, then adheres to the surface and can cause rusting. The following therefore applies: Separate White and Black material to prevent rust stains. However, if you look after your pool properly and clean it thoroughly after contact with the wrong medium, you can prevent rust stains.

Do you have any tips on how to prevent or remove rust stains?

It is important that Stainless steel surfaces are also cared for. There are special care products on the market that are specifically designed for Stainless steel. They can be used to freshen up the surfaces and remove any small rust stains.

Stainless steel surfaces also need to be maintained.

Is there also the wrong care?

If you are not sure, you should first and foremost rinse with plenty of water if the pool has come into contact with a medium that could possibly cause rust. Salt residues, for example, can be easily removed in this way. Otherwise, I would refer you to conventional care products.

Stainless steel is generally a very low-maintenance material.

Expert tip: You can find more interesting information on the subject of “Stainless steel” on the website of the Information Center for Stainless Steel (ISER): https: //www.edelstahl-rostfrei.de/

Thank you very much for the interview Mr. Hajicek!

The KUNe “Do it yourself” quick tip for removing rust stains:

• 1 to 2 heaped tablespoons of citric acid powder(available in grocery stores in the baked goods section),
• and 2 heaped tablespoons of salt
• in 1 liter of lukewarm water.

Allow the stains to react with this solution for a few minutes and then rinse with plenty of clean water.

You don’t know why rust stains have appeared on the stainless steel surface? Even the right care doesn’t help? Then please contact us, we are here for you: service@kune-online.com