You often hear the terms 316 and 316L stainless steel when working in industries like construction, marine engineering, and medical equipment. Many people assume that they are the same, with only minor naming differences.
However, it’s not the truth. Both 316 and 316L are austenitic stainless steels known for their excellent corrosion resistance, but they differ in their carbon content. Continue reading as we explore 316 vs 316L stainless steel in detail, along with their advantages!
What Is 316 Stainless Steel?
316 stainless steel is an austenitic chromium-nickel compound that also contains 2% to 3% of molybdenum. It’s also called marine-grade steel and can easily withstand exposure to high levels of corrosion, chlorides, and acids. This material is in high demand, and its market was valued at USD 1.76 billion in 2023 and will reach USD 3.05 billion by 2032.
What Is 316L Stainless Steel?
316L, on the other hand, as the name implies, is a low-carbon, austenitic stainless steel that’s designed to resist pitting and chloride corrosion. It also has high weldability and durability compared to the traditional 316 stainless steel. It’s also known as medical-grade steel and finds its way in jewelry and marine environments.
316 vs 316L Stainless Steel: Key Differences
In 316 vs 316L stainless steel, there are many differences in their weldability, corrosion resistance, heat protection, and mechanical properties. Let’s discuss these in detail:
Carbon Content
Type 316 has a maximum carbon content of 0.08%, while 316L has a maximum of 0.03%. This low carbon content reduces the chance of chromium carbide precipitation during and post-welding. However, other elements such as nickel, chromium, and molybdenum are present in the same amounts in both.
Corrosion Resistance
In 316 vs 316L stainless steel, the former offers moderate corrosion resistance. Contrarily, 316L has an incredible corrosion-resistant nature since it doesn’t form chromium carbide precipitates.
There’s plenty of chromium present that interacts with oxygen to make a self-healing chromium oxide layer. So even when the 316L stainless steel gets damaged, the layer heals itself, providing extensive protection.
Weldability
The weldability of 316L is higher than that of 316 stainless steel. It’s due to the low carbon content, which doesn’t provide enough strength, so you can bend and shape it easily. What’s truly amazing is that it also offers better corrosion resistance at welded joints than standard 316, making it suitable for harsh environments.
Mechanical Properties
When it comes to tensile and yield strength, 316 stainless steel is superior, suitable for high-stress applications. 316L is also good, but it’s prone to cracking and may need treatments such as:
- Shot peening
- Low plasticity burnishing
- Water jet cavitation peening
- Solution annealing
- Grinding and polishing
Heat Resistance
Both grades 316 and 316L offer excellent oxidation resistance, but at high temperatures, 316 is prone to carbide precipitation. This weakens its ability to resist corrosion and rust, causing it to be damaged more quickly than 316L.
Price Difference
Well, 316 and 316L are priced almost the same, but in some cases, the former is slightly more expensive due to its higher carbon content and strength. 316L is more affordable in applications that involve welding, so you don’t need to invest in post-weld annealing.
316 vs 316L Stainless Steel Comparison Table
The following table gives you a better understanding of 316 vs 316L stainless steel for quick decision-making:
Property | 316 Stainless Steel | 316L Stainless Steel |
Carbon Content | Up to 0.08% | Up to 0.03% (low carbon) |
Corrosion Resistant | Good corrosion resistance | Superior corrosion resistance |
Weldability | Good, but requires post-weld annealing | Excellent, no post-weld annealing required |
Mechanical Strength | Higher tensile and yield strength | Slightly lower strength |
Cost | Slightly more expensive in some cases | Comparable or slightly cheaper |
Why 316 and 316L Are Often Confused
There are many reasons that 316 and 316L are confused and thought to be the same. For instance, both are molybdenum-bearing austenitic steels, sharing high levels of chromium and nickel. So their performance in marine and other environments is pretty much the same, except that traditional 316 corrodes more quickly. In addition, they are priced closely in the market, so choosing one over the other won’t give you any major financial edge.
When to Choose 316 Stainless Steel?
You can choose 316 in 316 vs 316L stainless steel for applications that are exposed to coastal air, chlorides, or other harsh chemicals. In scenarios where you are unable to use 304, you can use 316, as it has molybdenum to resist pitting.
When to Choose 316L Stainless Steel?
In 316 vs 316L, choose the latter when your project involves welding, high temperature service, or excellent corrosion resistance. Common examples include pharmaceuticals, food processing, and marine fabrication.
Common Applications of 316 and 316L
Since the chemical composition of both 316 and 316L is pretty much the same except for carbon content, they share multiple common applications, such as:
Marine Equipment
Both 316 and 316L are corrosion-resistant and used in marine equipment such as cleats, winches, shackles, mooring components, and masts. In addition, 316L is also suitable for marine piping, exhaust systems, and structural tanks.
Chemical Processing
As mentioned earlier, these stainless steel grades can resist acids and chloride solutions, hence they are suitable for chemical processing. For instance, you can use them in constructing tanks, reactors, and storage containers. Perhaps, you may also employ this material in valves, pumps, and heat exchangers.
Medical and Food Equipment
Due to their high hygienic properties, 316 and 316L are used in medical and food equipment. 316L is used for orthopedic implants as well as high-strength surgical tools. Both grades are also suitable for bioreactors, vessels, and food-processing equipment.
Welded Structures
In 316 vs 316L, both these grades are suitable for welded structures. However, since 316 has low carbon, it’s only used in less demanding, thin-walled structures where welding is minimal. On the other hand, 316L can handle all types of welding while maintaining high resistance to weld decay.
How to Select the Right Grade for Your Project?
To select the right option in 316 vs 316L, you should carefully understand your project requirements, like corrosion exposure and strength needs. For instance, you should choose 316 if you require durability and high strength. However, for projects that involve extensive welding, 316L is the right choice.
Frequently Asked Questions
Is 316L better than 316?
Yes, 316L is considered better than 316 when you require high corrosion resistance and welding.
Can 316 replace 316L?
Yes, 316 can replace 316L in many applications, but it depends primarily on whether the project requires welding.
Which one is better for welding?
In 316 vs 316L, 316L is the better choice for welding as it doesn’t require annealing and offers high corrosion resistance.
Is 316L more corrosion-resistant?
Yes, 316L is more corrosion-resistant since it doesn’t form chromium-carbide precipitates.
Request a Quote for 316 and 316L Stainless Steel
In 316 vs 316L stainless steel, the right choice is the one that matches your budget and needs. Looking for certified stainless steel products? Get in touch with Jianglin today and request a quote for your custom order!
