316 vs 316L: The Complete Guide
316 and 316L are both alloys of steel which possess certain desirable properties. They are generally known as ‘marine-grade’ stainless steel materials due to their ability to withstand corrosive marine environments. Both alloys contain similar elements such as carbon, molybdenum, nickel, iron, chromium, etc. albeit in different quantities.
What Is Stainless Steel?
Stainless steel (SS) is a metallic material that contains iron and chromium elements making it an alloy. The composition of chromium must be at least 11% in any stainless steel with other elements varying in composition. Additionally, the composition of other elements will depend on the qualities to be exhibited by steel.
What Is 316 Stainless Steel?
This is an alloy of steel that is non-magnetic in nature. It is composed of carbon material of up to 0.08% and molybdenum content of between 2-3%. The extra molybdenum content makes it corrosive and pitting resistant, thus ideal for use in acidic and high temperature environments.
What Is 316L Stainless Steel?
316L stainless steel is an alloy of stainless steel which contains low carbon content; a maximum of 0.03%. This low carbon composition reduces carbon precipitation risk during welding process thus maintaining maximum corrosion resistant properties. When heat is introduced, carbon is drawn from the metal and reacts with chromium materials leading to loss of corrosion resistance properties.
Additionally, it exhibits great pitting and crevice corrosion properties compared to other stainless steel grades. It is able remain stronger at higher temperatures, offer higher stress to rapture capabilities and high quality formidability. These makes it the preferred metal for fabricators and manufacturers.
316 Stainless Steel Properties
These are unique characteristics that only identify with 316 stainless steel material and determine their applications. They include;
- High malleability makes it easy to mould it into different shapes without cracking.
- Highly corrosion resistant towards pitting and crevice whenever in chloride solutions.
- High melting points of between 13710C-13990C hence can withstand high temperature conditions.
- Its material elasticity is at 193GPa.
- Being an austenite material, it possesses good forming and welding properties.
- It has a weight of 7.93g/cm3
- Very strong metal thus is used in construction and infrastructure making.
- Can be easily made into rolls.
- Minimum tensile strength of 515 MPa.
316L Stainless Steel Properties
- 316L stainless steel contains low carbon levels (0.03%) than 316 stainless steel. Making it excellent for use in high temperature and corrosive resistant applications.
- Though naturally austenitic but has higher chances of gaining magnetic properties when taken through cold forming or welding processes.
- Highly formidable and can be made into different forms; sheets, strips, pipes and plates without breaking or losing its properties.
- 316L stainless steel does not leach its chemical compounds when in contact with other elements. This ensure that its chemical property is maintained throughout. Furthermore, this makes it safe for use in various applications such as food and medical industries.
- 316L is naturally appealing and easy to maintain.
- Very durable material thus can last longer.
- Does not undergo oxidation process which results into rusting. The addition of molybdenum improves the rusting properties further.
Comparing 316 Vs 316L
· Similarities Of 316 vs 316 316L Stainless Steel
- Both are alloys of stainless steel material containing similar elements of different compositions.
- Are referred as marine grade stainless steel due to their ability to withstand harsh corrosive conditions.
- 316 stainless steel and 316L stainless steel cost approximately the same.
- Both are corrosive resistant due to the presence of molybdenum element
· Differences Between 316 vs 316L Stainless Steel
- 316L stainless steel contains less carbon; 0.03% than 316 stainless steel (0.08%). This makes 316L superior in corrosive resistant compared to 316.
- 316 stainless steel has better mechanical properties in terms of tensile strength, ductility and hardness compared to 316L stainless steel.
|Property||316 stainless steel||316L stainless steel|
|Yield strength, min (ksi)||30||25|
|Hardness, max (Rb)||95||95|
|Elongation, min (%)||40||40|
|Tensile strength, min (ksi)||75||70|
- Because of carbide precipitation immunity 316L stainless steel is more preferred in welding and medical applications than 316 stainless steel. However, 316 can be annealed to exhibit similar welding properties as 316L.
316 vs. 316L Applications
Due to its high strength and resistance to pitting, 316 is a perfect choice for most construction and fabrication work. You can use 316 materials to make beams, window frames, bridges, staircases, or other structural frame designs.
316L is prevalent in this industry due to its excellent corrosion resistance, chemical resistance, etc. You can use it for medical implants, laboratory accessories, medicine manufacturing equipment, pharmaceutical bins, etc. 316L is suitable for applications requiring a lot of welding.
316 is a perfect choice for applications that need corrosion-resistant metals. These may include heat exchanger systems, furnace parts, jet engine parts, exhaust manifolds, photographic equipment, pumps, evaporators, chemical processors, etc. Additionally, it performs well in marine environments.
Being versatile, you can use 316L material in many applications such as chemical processing, food processing, marine, jewelry, water treatment, and power generation industries.
People Also Ask
Selecting between 316 and 316L in terms of superiority will depend on the project at hand. Below factors can be considered;
- Corrosion resistance
316L is highly corrosive resistance compared to 316 due to carbon precipitate immunity.
- Mechanical properties
316SS has better mechanical properties than 316LSS.
- Both materials cost relatively the same.
316 stainless steel is softer than 316 stainless steel due to the low carbon element quantities. The low carbon in 316LSS makes it easy to weld and form the steel into various forms and shapes without any issues. Therefore, it is the most common steel in welding-related applications.
The ‘L’ stands for low carbon composition (0.03%) in the steel and is responsible for excellent anti-corrosive properties. This is because low carbon levels prevent carbide precipitation during steel fabrication process thus maintaining excellent corrosive resistant properties. As a result, 316L stainless steel is commonly used in welding related applications.
- Higher temperature lower tensile strength for 304 stainless steel and raises for 316SS.
- 316SS has better corrosion resistance to acids compared to 304SS due to molybdenum addition.
- 316SS grades are pricier than 304SS due to Molybdenum addition.
- 304SS is common in food industry, whereas 316SS is used in marine environment.
When looking for versatile stainless steel that can be welded into different shapes, consider 316LSS. 316LSS can be utilized in marine vessels that are exposed to corrosive conditions that may lead to pitting and crevices. Either 316 or 316L can be used when looking for strong stainless steel material.