Effekter av livsmedelsförädling för lokalkorrosion på rostfritt stål 316L

Sammanfattning: Pitting corrosion on 316L stainless steel has been widely studied, but knowledge is lacking within food processing environments. A new test setup was developed to enable electrochemical measurements inside a heat exchanger (pasteurizer) where solutions can be heated and cooled rapidly, allowing for corrosion tests of solutions that do not withstand high temperatures for a long period of time. After the development of a new test setup, the effects of chloride, acetic acid and temperature on the pitting corrosion of stainless steel were tested by electrochemical means. The measurements showed chloride concentration has the largest impact on the pitting potential, followed by temperature but the effect trailed off between 80 and 100 °C. The effect of acetic acid was small and difficult to understand, the addition of acetic acid seemed to increase the pitting resistance at low chloride concentrations while decreasing the resistance at higher chloride concentrations. Virtually no difference was seen between the different concentrations of acetic acid used.