Carbon Steel vs Stainless Steel: Pros and Cons, and Applications

The fact that two objects are made of steel does not imply that they contain the same steel. The two most popular types of steel are carbon steel and stainless steel, though there are many others. Although both varieties are the same, several significant differences set one apart from the other.

Carbon Steel

The American Iron and Steel Institute (AISI) defines carbon steel, with a carbon content of up to 2.1% by weight, based on a specific set of requirements.

• There is no minimum content required for metals that resist corrosion, such as vanadium, titanium, tungsten, cobalt, and chromium.
• Copper content requirements must not be less than 0.40 percent.
• Manganese cannot be present in concentrations more than 1.65%.
• Copper cannot be present in amounts more than 0.6 percent.
• A maximum of 0.6 percent silicon may be included.

Carbon steel is more rigid, has a matte finish, and has a higher tensile strength than stainless steel. Knives and other bladed cutting tools that need to keep their cutting edge longer are made from this material. However, even modest amounts of moisture will cause this steel to oxidize. Carbon steel is not as ductile or straightforward to form as stainless steel.

Stainless Steel

Stainless steel, also known as inox steel, lives up to its name by highly resisting rust-related discoloration. Steel and other iron-based metals usually undergo a chemical process called oxidation when exposed to oxygen, which alters their characteristics. Iron oxidizes, transforming the previously metallic iron into a reddish-brown metal (iron oxide). The iron oxide will eventually oxidize to the point of complete disintegration.

Stainless steel has an oxidation-resistant coating. It has a chromium concentration of at least 10.5 per cent by mass. Unlike chromium, iron is prone to oxidation, which is why this is crucial. In stainless steel, a layer of chromium serves as a barrier between the oxygen in the environment and the metal's iron content, preventing corrosion.

Equipment and utensils used in the food industry, medical equipment, automobile parts, and many other items are made of stainless steel. Stainless steel never oxidizes or rusts, unlike other iron and steel goods, which is its most crucial feature. Stainless steel is a preferred material for many applications due to its strength, corrosion resistance, visual appeal, and ease of maintenance. There are panels composed of a glossy metal material all around you whenever you enter a commercial kitchen or a hospital.

Read More: How to drill Stainless Steel

Carbon Steel vs. Stainless Steel: What's the Difference?

Here are some differences between carbon and stainless steel:

1. Corrosion Resistance

The most noticeable difference between carbon steel and stainless steel is their capacity to withstand corrosion. Stainless steels are typically more resistant to corrosion than carbon steels, as their name suggests. Iron is present in both carbon and stainless steel, where it oxidizes in the presence of oxygen to form rust. Chromium makes stainless steel more corrosion-resistant than carbon steel

2. Mechanical Properties

Because there are so many different types and grades of each steel, it is challenging to generalize how carbon steel and stainless steel differ in terms of their mechanical properties. However, there are some general trends.

In general, carbon steel, especially the higher-carbon grades, has greater tensile strength and hardness than most stainless steels. This makes it more resistant to breaking under tensile forces. Because of the alloying elements included in many stainless steel grades that increase their strength, carbon steel with very low carbon content may not be able to meet the tensile strengths of some stainless steels. However, carbon steel can be heat-treated more quickly than austenitic stainless steel if it contains enough carbon (usually at least 0.30 percent by weight) to make it significantly stronger.

Because of their characteristic high nickel content, some grades of stainless steel are more ductile and malleable than carbon steel, which means they are easier to shape without breaking. However, other stainless steel grades are extremely brittle, such as the martensitic grades used in cutting tools.

3. Appearance

When aesthetic appearance is critical, stainless steel with specific treatments is typically used. Both materials can be sanded and polished to have a brilliant, shining appearance, but carbon steel needs paint or a clear finish straight away after the polishing procedure. The carbon steel will start to discolour and finally rust if it is not coated. Additionally, stainless steel will maintain its shine where it has been scratched, unlike painted carbon steel, which needs to be repainted or recoated.

4. Cost

Stainless steels are often more expensive than carbon steels, though prices vary depending on the grade. This is mainly because stainless steel has several alloying metals, such as chromium, nickel, manganese, and others. All of these extra components result in a higher price compared to carbon steel. Carbon steel, composed mainly of affordable iron and carbon, is an excellent, cost-effective option for your next project.

When to Choose Carbon Steel vs. Stainless Steel: Applications

The best choice between carbon steel and stainless steel is what you need it for. Corrosion resistance is usually the main thing to consider.

Choose Carbon Steel for:

• Structural and heavy-duty applications: Because of its excellent hardness and tensile strength, carbon steel is ideal for construction, bridges, railways, and industrial machinery where strength is essential.
• Cutting tools: High-carbon steel is an excellent choice for knives and blades because it retains its sharp edge for a long time.
• Budget-sensitive projects: Carbon steel is an affordable option when the environment is not corrosive because it is less expensive to produce.

Choose Stainless Steel for:

• Hygienic and food-grade applications: Its non-porous and easy-to-clean surface makes it indispensable for food processing equipment, medical devices, and commercial kitchens.
• Corrosive environments: Stainless steel's ability to resist rust and corrosion makes it the only practical choice for marine environments, chemical processing plants, and outdoor architectural components.
• Aesthetic appeal: Stainless steel's lustrous finish and low-maintenance properties make it a preferred material for architectural finishes, kitchen appliances, and automotive trim.

How To Choose Between Carbon Steel and Stainless Steel

Consider these factors carefully when choosing between carbon steel and stainless steel for a specific application. Spending more money on stainless steel just for its beauty makes no sense if the metal will be hidden from view. However, stainless steel can be the ideal choice if it is out of sight but exposed to corrosive conditions.