Caracterização dos mecanismos de corrosão para os aços inoxidáveis martensíticos AISI 414 e AISI 415 a partir de técnicas eletroquímicas

Abstract

As a final part of the steel production chain, continuous casting exposes its rollers to high process temperatures, thermal/mechanical fatigue, abrasive wear and corrosion damage. Martensitic stainless steels are the most widely used in industry and collapse from the emergence of failures as a result of the nucleation and propagation of pits and cracks. Pitting and crevice corrosion are the most common and the anodic dissolution of the metal is accelerated by the presence of HF, which will be formed from the reaction of CaF2, mold flow component, and water at high temperatures. Thus, the corrosion mechanisms of the AISI 414 and AISI 415 steels were investigated using electrochemical techniques of the open circuit potential and potentiodynamic polarization in order to study the influence of NaCl concentration on corrosive behavior. The results showed that for AISI 414, the OCP values were more negative and the polarization curves tended to decrease potentials and increase current densities. For AISI 415, the results showed increasing OCP values and polarization graphs tending towards more positive potentials and lower current densities.