If you want to buy something made of stainless steel, you may be trying to decide between 2205 duplex stainless steel and 316 stainless steel. This can be a hard choice to make because both options have pros and cons. Let’s look at these two things to help you decide which one will work best for you.
2205 Duplex Stainless Steel
Grade 2205 is made of 22% chromium, 5% nickel, and 3% molybdenum. It is a duplex stainless steel alloy. This grade of stainless steel is very resistant to corrosion, which makes it perfect for use in shipbuilding, oil platforms, and wind turbines that are out at sea. It also has a high strength-to-weight ratio, which makes it perfect for situations where strength is needed but weight needs to be kept to a minimum. It is a good choice for cryogenic applications because it doesn’t expand much when it gets hot.
316 Stainless Steel
Grade 316 is an austenitic chromium-nickel stainless steel alloy made up of 16%-18% chromium, 10%-14% nickel, and 2%-3% molybdenum. It is one of the most common grades of stainless steel because it is very resistant to corrosion and can be shaped well. Grade 316 is used a lot in the food processing industry because it can withstand high temperatures (up to 870°C) and doesn’t rust or corrode easily. It is also often used to make medical equipment because it doesn’t react with body fluids or irritate the skin when it is touched. Grade 316 is also very tough, which makes it a good choice for use in industrial settings where bumps and scratches happen often.
Grade 2205 vs 316 Stainless Steel
Chemical Composition
The first difference between stainless steel grades 2205 and 316 is how they are made. There are more chromium, manganese, and nitrogen in grade 2205 than in grade 316. This makes it stronger than grade 316 SS, but it also makes it more likely to rust than grade 316 SS. On the other hand, Grade 316 SS has more molybdenum and nickel, which makes it more resistant to corrosion than 2205 SS. The way each type of stainless steel works in different environments depends on how its chemical makeup is different.
Corrosion Resistance
When it comes to corrosion resistance, both grades have great resistance to general corrosion in air and water-based media like tap water or swimming pool water. But grade 316 SS is better at resisting corrosion from things like saltwater or acidic solutions, which are used in some industrial processes and food processing. Also, grade 2205 SS shouldn’t be used in places where there are high levels of chloride because this can cause pitting or crevice corrosion to happen quickly.
Weldability
One big difference between these two grades is how easy they are to weld. Grade 2205 is much easier to weld than Grade 316 SS because it has less molybdenum and nickel in it. This makes fusion welding easier and less likely to cause cracks or holes. On the other hand, Grade 316 SS needs to be preheated before it can be welded. This lowers the chance of cracking, which can happen when welding high-carbon steels like 304 and 321 series austenitic alloys at high temperatures. Also, depending on the application, post-weld heat treatment (PWHT) may be needed. This adds extra cost and time to fabrication operations that use Grade 316SS materials.
Conclusion:
When choosing between 2205 duplex stainless steel and 316 stainless steel for your next project or application, think about how the material will be used and how long it needs to last. Both materials are very resistant to corrosion in certain environments, but when put next to each other, they each have their own advantages. With this information in hand, you’ll be able to choose the material that meets your needs the best. Best of luck!