When it comes to the difference between carbon steel and stainless steel, what comes to our mind first is the rust-resistance ability. As we all know that carbon steel is more likely to be rust, so we choose stainless steel for special applications in the construction project. But do you know the other differences between stainless steel and carbon steel?

This article will discuss the difference between carbon steel and stainless steel. 

Corrosion Resistance

The most obvious difference between carbon steels and stainless steels is the ability to resist corrosion. When exposed to the outer environment, both carbon steel and stainless steels contain iron oxidizes which is easy to rust and corrosion. 

The added chromium in stainless steel makes it more corrosion resistant than carbon steels. When the chromium attaches to the oxygen, it creates a chromium oxide layer that protects the rest of the material from degradation and corrosion.

Carbon steel does not typically have enough chromium to form this chromium oxide layer, allowing oxygen to bond with the iron which results in iron oxide, or rust.

So if corrosion resistance is a key factor, stainless steel is the way to go.

Mechanical Properties

Stainless steels can be more ductile than carbon steels because they usually have higher amounts of nickel. However, there are very brittle grades of stainless steel as well, such as the martensitic grades.

Carbon steels with very low amounts of carbon may not match tensile strengths of some stainless steels due to the alloying elements that many stainless steel grades contain which increase its strength. However, if there is enough carbon in carbon steel, it is more readily heat treated than austenitic stainless steel.

Appearance

If the job requires an aesthetic appeal, the appearance of the metal must be considered. Stainless steels with particular finishes are generally preferred when cosmetic appearance is a factor. Although both can be sanded and polished to have a bright, shiny look, carbon steel requires a clear coat or paint rather quickly after the polishing process. If it is not applied, the carbon steel will begin to tarnish and eventually rust. Also, if the stainless steel is scratched, it will retain its luster in the scratched area, while a painted piece of carbon steel would need to be repainted or it will be subject to corrosion.

Cost

Another important consideration is cost. Although different grades have varying costs, stainless steels are generally more expensive than carbon steels. Compared to stainless steel,  carbon steel is mostly composed of relatively affordable iron and carbon elements. If you’re working with a tight budget on your next project, carbon steel might be the best option.

How to Choose?

Choosing between carbon steel and stainless steel for a particular job will involve weighing all of these factors and careful consideration. If the metal is going to be hidden from sight, there is no sense in spending extra money on stainless steel strictly for its appearance. However, if it is going to be hidden from sight but subject to a corrosive environment, stainless steel may actually be the best option. In the end, the choice will depend on the specifics of the job or project.