Per: Paulo Guilherme Gonçalves de Araujo (Faculdade de Engenharia - UNESP, Campus de Guaratinguetá), Florencia Furch (universidad Tecnológica nacional - Facultad Regional Córdoba), Igor Alexandre Fioravante (FACULDADE DE ENGENHARIA - UNESP, CAMPUS DE GUARATINGUETÁ), Jonas Fernando Macedo (FACULDADE DE ENGENHARIA - UNESP, CAMPUS DE GUARATINGUETÁ), Heloisa Andréa Acciari (FACULDADE DE ENGENHARIA - UNESP, CAMPUS DE GUARATINGUETÁ), Roberto Zenhei Nakazato (FACULDADE DE ENGENHARIA - UNESP, CAMPUS DE GUARATINGUETÁ), Eduardo Norberto Codaro (FACULDADE DE ENGENHARIA - UNESP, CAMPUS DE GUARATINGUETÁ)
Abstract:
The aim of this study was to investigate the effect of microstructure and composition on the corrosion behavior of api 5l x65 microalloyed steels in acid media. X65MS (Cr-enriched) and X65M (Ni- and Cu-enriched) steels show a ferritic-pearlitic microstructure. The former exhibited high ferrite grain refinement, whereas the latter exhibited a coarse microstructure with bands. In deaerated acid medium, the electrochemical behavior of both steels was similar and the values of the corrosion parameters were very close. When the deaerated medium was saturated with H2S, the corrosion potentials were lower, corrosion current densities and hydrogen permeation current densities were higher, in particular, in X65M steel. It showed lower general and localized corrosion resistances in both media, probably because it is more heterogeneous and more phases are present in its microstructure.