Stainless steel is the main difference between 304 and 321, 304 do not contain Ti, contains 321 Ti, Ti can prevent sensitization of stainless steel, popular is to improve the service life of the stainless steel and high temperature, that is to say under the environment of high temperature, suitable for 321 stainless steel plate than 304 stainless steel plate. Both 304 and 321 are austenitic stainless steels with similar appearance and physical properties except for a slight difference in chemical composition
First, titanium (Ti) 321 stainless steel requirements contained elements (according to the prescribed standards ASTM A182-2008 Ti content should not be less than 5 times of carbon (C) content, but less than 0.7%, the other note, 304, and 321 carbon (C) content is 0.08%), and does not contain titanium (Ti) in 304.
Second, the requirements for nickel content are slightly different, with 304 between 8 and 11 per cent, and 321 between 9 and 12 per cent.
Third, requirements for chromium (Cr) content vary, with 304 between 18 and 20 per cent, and 321 between 17 and 19 per cent.
So you can use a metal material analyzer or a chemical analysis method to determine the composition of these two materials and make a judgment
If you want to know the difference between other types of stainless steel, what's the difference between 304 and 316 stainless steel 304 and 201