Stainless Steel Grade 321 Is An Austenitic Chromium-Nickel Alloyed Steel. In spite of the fact that 321 SS Bar Is Similar To Grade 304 Stainless Steel, The Main Difference Is That 321 SS Bar Contains Titanium. For Fabricated Parts Like The 321 Stainless Steel Flat Bar Which Is Fabricated By Welding And Is Not Annealed Subsequently, Titanium Is Highly Recommended. Adding titanium to the alloy of the 321 stainless steel rod prevents and reduces carbide precipitation during welding at temperatures between 800°F and 1500°F. Additionally, titanium improves the alloy's properties at elevated temperatures. Download this PDF for more information about this product.