Is 321 stainless better than 304?

 

CHEMICAL COMPOSITION

304 Stainless is a low-carbon austenitic stainless steel alloy that contains chromium (18%) and nickel (8%) as its main alloying elements. It is the most commonly used stainless steel alloy due to its good corrosion resistance, ease of fabrication, and low cost.

321 Stainless is a stabilized austenitic stainless steel alloy that contains chromium (17%-19%), nickel (9%-12%), and titanium (5x[C]+0.7%) as its main alloying elements. Titanium is added to the alloy to stabilize it at high temperatures, making it more resistant to intergranular corrosion and sensitization.

MECHANICAL PROPERTIES

304 Stainless has excellent corrosion resistance, good formability, and high strength. It has a maximum operating temperature of around 1472°F and a maximum strength of around 90 ksi.

321 Stainless has similar corrosion resistance, formability, and strength as 304 Stainless, but it is more resistant to high-temperature oxidation and creep. It has a maximum operating temperature of around 1580°F and a maximum strength of around 95 ksi.