The ideal metallographic structure of duplex stainless steel is 50% ferrite and 50% austenite. Generally, the minimum phase content must reach 30%. It has the advantages of both austenitic stainless steel and ferritic stainless steel. Commonly used grades are: 2304, 2205, 2507, 2707, etc. Generally speaking, austenitic stainless steel is non-magnetic or weakly magnetic, while duplex steel is magnetic. In other words: it has the characteristics of stainless steel and the characteristics of carbon steel!

Super stainless steel, nickel-based alloy is a special type of stainless steel. First of all, it is different from ordinary stainless steel 304 in chemical composition. It refers to a high-alloy stainless steel containing high nickel, high chromium, and high molybdenum. Secondly, in terms of high temperature resistance or corrosion resistance, compared with 304, it has better high temperature resistance or corrosion resistance and is irreplaceable. In addition, from the classification of stainless steel, the metallographic structure of special stainless steel is a stable austenite metallographic structure. ​

904L super austenitic stainless steel is a low-carbon, high-nickel, molybdenum austenitic stainless acid-resistant steel. It is a proprietary material imported from French H·S Company. It has good activation-passivation transition ability, excellent corrosion resistance, good corrosion resistance in non-oxidizing acids such as sulfuric acid, acetic acid, formic acid, and phosphoric acid, and good corrosion resistance in neutral chlorine-containing media. Excellent resistance to pitting corrosion, as well as good resistance to crevice corrosion and stress corrosion. It is suitable for sulfuric acid of various concentrations below 70°C. It can withstand acetic acid of any concentration and temperature under normal pressure and has good corrosion resistance in mixed acids of formic acid and acetic acid.

Why is 254SMO (S31254) called Alloy254/F44 stainless steel?

What is Super Duplex Stainless Steel 2507

What are the main components of 2205 duplex stainless steel?