engleski

SS-316L Passivation Process in the Pharmaceutical Industry

System modification, expansion, redesign, repairs, external contamination, human error, direct contact with iron or chlorides, or direct exposure to contaminated atmosphere and especially welding processes are the reasons underlying the passivation process on the equipment surface made of austenitic stainless steel used in the pharmaceutical industry. In this work, the "pasivation process" is used to indicate a surface condition obtained by oxidation of the alloy surface. The "passive surface" refers to the state of the metal (alloy) surface characterised by low corrosion rates. Passivation process was investigated on the surface of the pharmaceutical system for injection (WFI-water for injection) made of SS-316L. Nitric acid with the CuSO4 . 5H20 passivator was used as the medium for SS-316L surface passsivation. The effects of passivation process and structure of oxide passive layers on mechanically polished and unpolished SS-316 L surfaces were tested before and after passivation by classical electrochemical techniques (potentiostatic and potentiodynamic) and analytical-surface techniques (SEM and EDAX-analyses).

Stainless Steel; passivation process; pasivators

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