Análise de microestrutural, de resistência à corrosão e de microdureza do aço ASTM 890 grau 3A em diferentes tempos de solubilização

Abstract

ASTM 890 grade 3 stainless steel duplex (AID) has great use in the oil tube industry in Brazil and worldwide. The material of the time variation necessary to solubilize a material is important, therefore, by decreasing this time, it can become spent with an furnace. The objective of this paper is the comparison of results for the different solubilization times of ASTM 890 grade 3A molten duplex stainless steel. A literature indicates that a solubilization a year must have the temperature of 1120 ° C, in theperiod of 4 hours. However, there are no results that show the influence of time intensity on the corrosion resistance of this material. In order to analyze it, 3 thermal intervals were made at 1120 ° C, in times 30 minutes, 2 hours and 4 hours. Grade 3A is characteristic, for example, it does not cover its composition, for example 1% w M and also 25% w Cr. The study was made a microstructural analysis under optical microscope to observe the differences in the phases of the material. Then, electrochemical tests of open circuit potential, impedance spectroscopy and anodic polarization, using a 1M NaCl electrolytic system, were used to verify the corrosion in the alloy. The test was made a review of the steel being exposed to tests of microhardness. Finally, the results were obtained with which expectations do not evolve.