Stainless steel is used extensively in food and beverage production. Its corrosion resistance, cleanability and resistance to bacteria retention make stainless steel ideal for this application. Contamination of foods and beverages from corrosion products, dissolved metal, or previous batches can be avoided using stainless steel equipment. Stainless steel is easily fabricated and its availability in multiple product forms is excellent.

The production of foods and beverages often requires processing at elevated temperatures. Most soups, meats, and vegetables also contain chlorides in the form of salt (sodium chloride). The high temperatures, chlorides, and residual stresses from fabrication of the equipment can cause chloride stress corrosion cracking in Type 304/304L and Type 316/316L austenitic stainless steels. This mechanism is especially likely when food or a process is heated through a stainless steel wall.

The cracking can also originate from the outside of a vessel. If a vessel is jacketed and insulated, condensate can get trapped in the insulation. Such condensate can concentrate to high chloride levels through evaporation at the heated surface.

This paper discusses case histories from the food production industry, where the standard austenitic stainless steels have suffered chloride stress corrosion cracking. Stainless steels with higher molybdenum contents have been used successfully to solve these problems. Examples of stainless steels that are stress corrosion cracking resistant are the duplex grades 2205 and 2507, and the 6% molybdenum austenitic stainless steels.