Occurrence of pitting corrosion in stainless steels

Na sučelju materijal (metal) / okoliš, uslijed kemijskih i elektrokemijskih reakcija događa se neželjena razgradnja materijala s promjenom traženih svojstava, tj. nastala je korozija materijala. Korozija nehrđajućih čelika u svom najintenzivnijem obliku je rupičasta korozija – korozija nastala tamo gdje se ne može očekivati. U prvom dijelu diplomskog rada je obrađena je teorija i kinetika korozije, dat je kratki pregled nehrđajućih čelika i kao najveći problem postojanosti nehrđajućih čelika, detaljnije je razrađen mehanizam rupičaste korozije. U eksperimentalnom dijelu provedena su ispitivanja na pet uzoraka napravljenih od različitih vrsta nehrđajućih čelika radi utvrđivanja, analize i usporedbe korozijskih oštećenja.At the material (metal) / environment interface, as a result of chemical and electrochemical reactions, an unwanted decomposition of the material occurs with a change in the requiredn properties, i.e. corrosion of the material has occurred. Stainless steels are alloys designed to be resistant to negative environmental influences. Stainless steel corrosion at its most intense is pitting corrosion – a localized form of corrosion that creates cavities or "holes" in the material that are difficult to detect, predict and prevent. In the first part of the thesis, the theory and kinetics of corrosion were treated, a brief overview of stainless steels was given, and pitting corrosion, as the biggest problem of stainless steel durability, was elaborated. In the experimental part, tests were carried out on five samples made of different types of stainless steel in order to determine, analyze and compare corrosion damage in a simulated marine environment