Stainless steel plays an important role in various industries owing to its strength, durability, and resistance to corrosion. However, the quality of stainless steel varies depending on its material composition. Two of the most commonly used types of stainless steel are duplex stainless steel and super duplex stainless steel. In this blog post, we will discuss the differences between these two types of stainless steel in detail.
Difference Between Duplex Stainless Steel and Super Duplex Stainless Steel
Chemical Composition:
Duplex stainless steel combines austenitic and ferritic stainless steel, while super duplex stainless steel contains higher amounts of chromium, molybdenum nickel, and nitrogen. This composition enhances the corrosion resistance of super duplex stainless steel.
Tensile Strength:
The yield strength of duplex stainless steel ranges between 450-630 MPa, and for super duplex stainless steel, the range is between 550-750 MPa. Super duplex stainless steel’s tensile strength is also higher than duplex stainless steel’s.
Corrosion Resistance:
Both duplex and super duplex stainless steel have excellent corrosion-resistant properties. However, super duplex stainless steel is known for its superior corrosion resistance in highly corrosive environments, making it a preferred choice in marine applications.
Weldability:
Duplex stainless steel welds better than super duplex stainless steel. Super duplex stainless steel is known for its sensitivity to welding defects, affecting its corrosion resistance properties. Proper welding techniques need to be ensured while using super duplex stainless steel.
Cost:
Super duplex stainless steel is a costlier option than duplex stainless steel due to its higher alloy content and superior properties.
Conclusion:
Duplex stainless steel and super duplex stainless steel have similar properties but differ in chemical composition, tensile strength, corrosion resistance, weldability, and cost. Both types of stainless steel have their applications, and choosing the right type depends on the project’s requirements. Overall, super duplex stainless steel is a preferred option for highly corrosive environments, while duplex stainless steel is a more economical option for other applications. Choose wisely!
