What scientific methods can be used to test 304 stainless steel?

A detailed explanation of the development history of duplex steel 2205 and super duplex steel 2507

Can anyone tell me which stainless steel is the strongest between 316L and 2205?

Austenitic stainless steel 317L (UNS S31703)

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. ​