KEY COMPONENTS:
  • Chromium (Cr) is an essential base ingredient in forming corrosion resistance. A chromium content of 17-20% is ideal. Higher chromium content can adversely affect mechanical properties required for food service cooking operations.
  • Nickel (Ni) increases the yield strength, toughness, and resistance to acids and corrosion (rust).
  • Molybdenum (Mo) is especially effective in increasing resistance to the initiation of pitting and crevice corrosion. In combination with chromium (Cr) it is very effective in stabilizing the steel against chlorides. Stress corrosion occurs if the carbon migrates to the grain boundary and is attacked by chlorides.
  • Carbon (C) is detrimental if it is present in a higher concentration and migrates to the grain boundaries. Stress corrosion primarily occurs at the grain boundaries and is accelerated by the presence of chlorides.

COMPOSITION OF STAINLESS STEEL ALLOYS

Component 430 304 304L 316 316L
Chromium (Cr) 16% 18% 18% 17% 17%
Nickel (Ni) None 8% 8% 12% 12%
Molybdenum (Mo) None None None 2.5% 2.5%
Carbon (C) 12% 8% 3% 10% 3%

  • 316L Stainless offers the maximum resistance to pitting and corrosion caused by cooking food products high in salts and acid content. (i.e., tomatoes and seafood).
  • 304 Stainless is the standard material used in the food service equipment manufacturing industry. Pitting and corrosion of the metal will take place when cooking foods high in acids and chlorides.
  • 430 Stainless is less expensive than 304 and 316 and is not resistant to pitting and corrosion (rust). 430 is used to reduce the cost of the product and still be called "stainless steel". 430 stainless is magnetic and can be checked by seeing if a magnet "sticks" to the surface.