The Use and Misuse of 300 Series Austenitic Stainless Steels in the Citrus Industry

The 300 series austenitic stainless steels have been used extensively and successfully in the Citrus Industry for numerous applications. Material cost and corrosion resistance to both citrus products and cleaning solutions for maintaining sanitary conditions has made type 304 and type 316 stainless steels the material of choice for process equipment, tanks, and piping systems. However, corrosion failures have occurred and many have been the subject of forensic investigations to determine the cause and provide recommendations to avoid future, similar problems. Historically, the primary modes of corrosion failure of T304SS and T316SS have been experienced not only in the Citrus Industry but also in the chemical and petrochemical industries. These modes of corrosion include localized corrosion in the form of pitting and crevice corrosion, and stress corrosion cracking. Successful long-term performance is best obtained when (1) the correct alloy is selected for the application; (2) piping and equipment are carefully fabricated and passivated prior to being placed in service; and (3) the process system design and operation minimizes stagnation and solids deposition, especially at elevated temperature. A table listing the composition of the most commonly available and specified 300 series austenitic stainless steels is shown in Table 1. Paper published with permission.