Análise de corrosão em aço STRENX 700 com Revestimento de óxido de titânio

Abstract

High Strength and Low Alloy Steels (HSLA) have the desired strength properties in metal frame designs and agricultural machinery, the mechanical properties allow up to 20% reduction in the weight of engineered frames compared to carbon steel. Despite the differences in chemical composition and mechanical properties between carbon and ARBL steels, all is susceptible to corrosion, taking to wear and tear, resulting in high costs for companies. In this work, an ARBL steel titanium oxide coating was applied using Plasma Magnetron Sputtering (PMS) to evaluate the effects of the coating on the corrosion rate of the material. For this, STRENX 700 steel samples was prepared and coated with titanium in three different deposition times and submitted to titanium oxidation processes by heat treatment, in muffle furnace, and chemical, using NaOH solution. After oxidation of the samples, analyzes performed by optical microscopy and field emission and electrochemical analyzes was performed in aerated solution of NaCl (3,5%), measuring open circuit potential, micropolarization and macropolarization. The data obtained from the experimental analyzes was calculated the corrosion rate in mm/year of both base metal (MB) and coated metal. The corrosion results obtained indicate that the heat treated oxidized titanium coating showed a reduction of the annual corrosion rate between 22.5% and 72.0%, when compared to MB (TT).