Stainless steel is a term that was coined early for the development of steels for different cutlery applications. It was adopted as one of the generic names for steels and until now it covers various steel types as well as grades for oxidation and corrosion resistant applications. Stainless steel is basically an iron alloy that contains a minimum of 10.5% chromium. There are several applications made using stainless steel and it is available to customers in different types, where super duplex stainless steel and duplex stainless steel is widely popular. So, friends here in this article I am going to let you know the difference between both these types of stainless steels in detail.
Difference between super duplex and duplex stainless steel
Before we distinguish and decide which stainless steel type is better let’s know both these types individually in detail.
Duplex stainless steel
This type of stainless steel have mixed microstructure of ferrite and austenite and its aim is to produce 50/50 mix of both the components in the commercial alloys. The mix can be 40/60 respectively. This kind of stainless steel has improved tensile strength over the austenitic stainless steel and it even has improved resistance to localized corrosion, mainly crevice corrosion, pitting as well as stress corrosion cracking.
Duplex stainless steel is mainly characterized by molybdenum up to 5% and high chromium up to 28% as well as the lower amount of nickel content as compared to austenitic stainless steel. however, the mostly used duplex stainless steel is 2205 in which the addition of 22% chromium and 5% nickel is done, while in type 2507 a mixture of 7% nickel and 25% chromium done and it is also known as super duplex because of its higher corrosion resistance.
The mechanical properties of this type of stainless steel are approximately double than the singular austenitic steel and are resistant to corrosion. It even has ductile or we can say brittle transition at a temperature of 50 degrees.
Super duplex stainless steel
Super duplex stainless steel is another popular stainless steel type that is known to have cracking resistance, stress corrosion and mechanical properties than any other stainless steel type. It is an austenitic-ferrite nickel and chromium alloy with the addition of molybdenum. The super duplex stainless steel has good resistance to pitting and has excellent tensile strength at moderate temperatures as compared to other conventional austenitic stainless steels.
Well, the high corrosion resistance of super duplex stainless steel type makes it an ideal for both offshore and onshore environments in different applications.
Both the stainless steel types whether duplex or super duplex have their properties and considered best for different industrial as well as domestic applications. Around the world, almost every manufacturer makes use of these stainless steel types for manufacturing applications and industrial equipment. They are well tested and inspected in accordance with industrial norms and regulations. Hence, you can easily both these stainless steel types for in any industrial application. They are available worldwide and you can purchase it from any of the reputable manufacturer, supplier or exporter around the world. So, this was about the stainless steel types duplex and super duplex stainless steel you must know.
To know more on difference between Duplex Stainless Steel Pipes And Super Duplex Pipes please read our other blog here