Influência dos parâmetros de tratamento térmico na resistência à corrosão de vergalhões CA-50

Abstract

The CA-50 carbon steel rebar is an essential component in civil construction, ensuring the resistance and durability of reinforced concrete structures. The corrosion of rebar in reinforced concrete is one of the most critical pathologies, as it compromises structural integrity, reduces the lifespan of buildings, and generates significant maintenance costs. This study aims to evaluate the effects of heat treatment parameters on the corrosion resistance and microstructure of CA-50 rebar. The influence of parameters, including heating rate, holding temperature, and holding time, was analyzed using a three-level factorial experimental design. Corrosion resistance was assessed through linear potentiodynamic polarization and electrochemical impedance spectroscopy techniques. The results indicated that both holding time and heating rate significantly affect the corrosion potential, while the corrosion current showed no relevant variations concerning the studied parameters. It was observed that holding time had a significant impact on polarization resistance, whereas holding temperature did not exert a direct influence on any of the response variables. Additionally, both increases and decreases in corrosion resistance were observed based on the microstructures formed after heat treatment. Thus, optimizing the heat treatment parameters can enhance the corrosion resistance of CA-50 rebar, due to the direct relationship with grain size and resulting microstructural characteristics.