Does High Carbon Steel Rust?

Carbon steel is an extremely sturdy alloy composed of iron and carbon. It is also very easy to sharpen, making it a popular kitchen knife material. The question of does high carbon steel rust? It comes up regularly, and we answer that on this page.

Yes, high carbon steel does rust. Every form of steel, especially those high in carbon, is prone to rust. Extensively, any material containing iron (Fe) can oxidize to create a layer of iron oxide, commonly referred to as rust.

High Carbon Steel is one of the most rust-resistant materials available. While it is not completely immune to corrosion and rust, the reality is that high-carbon steel only starts to get rusty after exposure to harsh corrosive environments. For example, saltwater (either at sea or in a salted road) will corrode high carbon steel after long-term exposure.

Also, carbon steel is a high-maintenance metal. Therefore, to prevent rust, you need to do lots of maintenance. Below, we have the information you need on how to go about maintaining and preventing your carbon steel from rust.

What Is High Carbon Steel?

Just as its name suggests, high carbon steel is steel with high carbon content. When iron is heated to a high temperature, it dissolves carbon, which would naturally precipitate after it cools down. However, if the metal that has been heated to liquid is cooled very quickly by the addition of water, the carbon present becomes trapped, unable to escape the iron, and distorts the structure of the substance thereby forming high carbon steel. If the carbon content of steel is continually increased to above 2%, it eventually becomes cast iron, a much denser, harder, and more brittle material, as a result of the impurities present.

What Is High Carbon Steel

The carbon present in steel increases its strength and improves its ability to harden by heat treatment. It also makes it less weldable and ductile than ordinary steel, and more brittle due to the presence of impurities.

Due to its extreme hardness and resistance to wear, high carbon steel is often used for things like cutting tools that retain their sharp edge, and hard nails that can be driven into strong concrete materials. Although, they tend to fracture when mistreated as a result of their brittleness also.

Unlike stainless steel, high carbon steel is not resistant to oxidation and rust. However, its rusting process is not very much faster than the low carbon steel or iron.

What Is The Difference Between Mild Steel And High Carbon Steel?

The main difference between mild steel and high carbon steel is that high carbon steel has a very high amount of carbon whereas mild steel has a reasonably low amount of carbon.

In general, steel can be referred to as carbon steel, however, it is quite relative as the amount of carbon present in steel is different. High carbon steel contains a high amount of carbon whereby mild steel is a form of low carbon steel.

Also, high carbon steel is stronger than mild steel, is brittle and breaks easily when compared to mild steel which can be easily welded into different shapes due to its weaker and softer properties.

Furthermore, carbon steel can successfully pass through and withstand heat treatments while it is impossible for mild steel to do the same.

Which Is Better: High Carbon Steel Or Stainless Steel?

The choice between high carbon steel and stainless steel depends on their quality of usage. While stainless steel is easy to store, and less brittle than high carbon steel, high carbon steel is harder than other steel grades. Also, rust prevention is easily carried out on stainless steel rather than high carbon steel.

However, high carbon steel can be honed to a very sharp surface and are generally more resistant to wear than their stainless counterparts. High carbon steel will hold a finer edge even when it is regularly used on tough objects or surfaces. Also, due to its hardness, high carbon steel is less likely to stay out of shape as a result of too much direct impact.

One major impediment however is that it needs more care than the stainless steel will require.

How To Prevent High Carbon Steel From Rusting

How To Prevent High Carbon Steel From Rusting

1. Apply a Dry Coating

You can prevent high carbon steel from rusting by applying a dry coating. Some products are specifically made to prevent steels from rusting. These products work in the same way as oil, by creating a protective barrier against rust without leaving behind any residue. A rust preventative dry coat is therefore very ideal for high carbon steel.

Dry coating materials can be applied by dip, wash, or spray. Once they dry upon the steel, the protective barrier is in place. The high carbon steel does not look or feel different in any way so its application remains the same.

Dry coatings can also be utilized in a variety of other ways to prevent rust. For instance, you can apply a dry coat over a painted high carbon steel object or powder coat, to increase its layer of protection.

2. Galvanization

This refers to an application of a protective coating of zinc over iron or steel. Zinc corrodes about thirty times slower than iron, as a result of this, galvanization can be a cheap and effective way to prevent rust.

However, the impediment you tend to face with galvanization is that zinc coating is usually unable to withstand harsh environmental conditions like salt or acid rain. Galvanization will also alter the physical appearance of high carbon steel and the extra layer can cover up some other parts of the component.

In Essence

High carbon steel rusts as a result of the reaction that occurs between the moisture present in it and the oxygen present in the environment. Any metal that contains iron can rust. To prevent this, you can apply a dry coat or galvanize high carbon steel. This is coating the high carbon steel material with zinc.

High carbon steel is generally durable and more resistant to wear.

Evan Cooper

Evan Cooper

Hi, I’m Evan Cooper, the founder and an editor of this site, Doesitrust. I’m a chemical engineer and working in a rust-eliminating paint manufacturing company. Besides this profession, I’m a researcher and blogger.

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