Re: SS 321 vs SS 316L. 01/08/2008 12:09 PM. The molybdenum gives 316 better overall corrosion resistant properties than Grade 321 (similar to 304, with Ti addition to improve temperature property within 800-1500 deg F), particularly higher resistance to pitting and crevice corrosion in chloride environments.
AISI 321 stainless steel is a stabilized version of SS 304 but with titanium. The titanium content in SS 321 Stainless Steel helps it prevent carbide precipitation while welding in temperatures ranging between 800 – 1500°F. It also allows the alloy to barely elevated temperatures. Grade 321 stainless steel is highly resistant to oxidation