This guide is your one-stop source for everything you need to know about this versatile, corrosion-resistant alloy.
We will be covering the properties of 218 stainless steel, its uses, and applications. We’ll also explain how it differs from other grades.
Whether you’re an experienced engineer or just starting out, this guide is meant for you.
Just keep on reading!
What is 218-Grade Stainless Steel?
Type 218 is a family of martensitic stainless steel. It is a medium-carbon alloy that is used in applications where strength and rust resistance are required. Also, it is known for its high wear and abrasion resistance.
The grade number (218) means the carbon amount in the alloy and the alloying elements used in its production.
Ways to Identify Stainless Steel 218
It is important you know how to identify the exact grade for your projects.
There are simple ways to identify if the stainless steel is grade 218:
- Look at the color of the steel. The 218 stainless steel is often silver in color but can also be gray or yellowish. It should not be black or red.
- Check for a magnet. Grade 218 is not magnetic, so if a magnet sticks to the material, then it is not 218.
- Examine the surface for scratches or dents. Grade 218 does not corrode easily and is relatively scratch-resistant.
- Have the steel tested with a nickel-chromium test. This test specifically checks for the presence of nickel and chromium, which determine if the steel is indeed grade 218.
- Consult with a metallurgist. A specialist in metals can help you identify.
Composition
Now let’s proceed to knowing the composition of 218 stainless steel.
The composition is as follows:
| Iron (Fe) | Balance |
| Chromium (Cr) | 16-18% |
| Nickel (Ni) | 10-14% |
| Manganese (Mn) | 2% |
| Nitrogen (N) | 10% |
| Sulfur (S) | .030% |
| Phosphorus (P) | .045% |
| Carbon (C) | .08% |
| Silicon (Si) | 1% |
Properties of 218 Stainless Steel
Its several properties are one of the reasons why it is popular today.
Let’s explore its properties:
- Rust-Resistant: Type 218 has excellent rust resistance, making it suitable for use in a wide range of environments.
- Strength: It also has a high strength-to-weight ratio, making it suitable for use in projects that require durability and strength.
- Heat Resistance: Stainless steel 218 has good heat resistance, allowing it to be used in high-temperature projects.
- Formability: It is highly formable and can be easily cut, formed, and machined.
- Weldability: All forms of 218 stainless steel are highly weldable, making it suitable for use in many welding applications.
- Cost: It is an economical choice for many applications due to its low cost.
Pros and Cons
Learning the pros and cons of a material can be beneficial. It can help you save time and money in the long run by ensuring that you are using the best material for the job.
| The Pros: | The Cons: |
| 218-grade stainless steel delivers extreme security against corrosive elements. Therefore, it is perfect for use in hostile environments. | Not strong as other steel grades. Meaning it is not good for projects requiring extreme strength or durability. |
| It is highly resistant to oxidation and can withstand extremely high temperatures without becoming brittle. | It is more expensive than any stainless steel, which makes it a costlier choice. |
| It has superior formability. This allows it to be made into complex shapes with super ease. | Type 218 is more susceptible to stress corrosion cracking. Then making it is less suitable for projects that may be subject to high temperatures, pressure, and/or other sources of stress. |
Primary Uses
Knowing the primary uses of a material is another important to consider. Why? Because it will help you to decide if this type of steel is suitable for the project or product you are working on.
In fact, the 218 stainless steel is useful in both industrial and commercial applications
Industrial Applications:
In industrial applications, type 218 is widely used in the:
- Food processing equipment (kitchen tools, cutlery, etc)
- Pharmaceutical processing equipment
- Petrochemical
- Chemical
- Surgical instruments
- Architectural projects
Commercial Applications:
In commercial applications, stainless steel 218 is commonly used to manufacture:
- Kitchenware
- Distillery tanks
- Brewery tanks
- Automotive exhaust systems
- Heat exchangers
- Pressure vessels
Which is Stronger, 218 or 316 Stainless Steel?
The strength of 316 and 218 stainless steel can be determined by their composition.
Type 218 contained chromium (16-18%), nickel (11-14%), and molybdenum (2-3%). This type is also popular for its high ductility and good weldability.
Type 316 contained 16-18% chromium, 10-14% nickel, and 2-3% molybdenum. It is also known for its good rust-proof properties and pitting resistance.
Stainless Steel 218 VS 304
There are a few key differences between 218 and 304 that should be considered.
Stainless steel 218 is known for its superior heat resistance and wearability. Then it is the preferred choice for most projects that require these properties. It is also more cost-effective than 304. Type 218 can be used in high-temperature environments due to acid resistance.
Stainless steel 304 is safer against corrosion than 218. Therefore it is the best choice for projects that needs additional protection from the environment. It is also much more durable than 218. Although 304 is more expensive, it is still suitable for many uses.
Generally, the choice between stainless steel 218 and 304 will depend on your specific application and budget.
Tips to Preserve 218 Stainless Steel
It is important to take the necessary steps to preserve stainless steel 218.
Here are some of the simple ideas:
- The first thing to do is to clean the stainless steel surface. Do this regularly. This can be done using a mild detergent and a soft cloth.
- Second, it is important to protect the material from high temperatures. This can be done by using a heat shield. Another way is by installing an exhaust fan in areas where the temperature is likely to exceed the recommended limits.
- Third, it is important to ensure that the material is not exposed to any chemicals or acids. If this occurs, it is important to immediately rinse the steel with water and a mild detergent.
- Finally, it is important to keep stainless steel 218 away from any moisture. So a protective coating can be a big help, samples are wax or oil. This helps prevent moisture from coming into contact with the material.
By following these tips, it is possible to maintain the integrity and beauty of 218 stainless steel for years to come.
CONCLUSION
The knowledge found in this guide can help you make wise decisions when you’re ready to purchase and use 218 stainless steel. With its reliable strength, corrosion resistance, and affordability, you won’t regret choosing it.
If you need an expert supplier for your 218 stainless steel needs, we’re ready to work with you! Contact us and expect professional assistance.