Análise da influência da austenita revertida na resistência à corrosão do aço maraging 300.

Abstract

Since its inception, maraging steels have gained wide application in engineering and industry, as their mechanical properties are of great use. These steels have a unique combination of high mechanical strength and fracture toughness. However, little is known about the resistance of these alloys to corrosion, and how their manufacturing process influences this property. Thus, this study gains importance, aiming to understand the corrosive process of these alloys. The present work aimed to study the influence of reversed austenite on the corrosion resistance of maraging 300 steel in an aqueous medium of 3.5% NaCl, under conditions for different aging heat treatment temperatures (480 ºC, 570 ºC, 600 ºC and 650 °C, all for 3 h). Seeking to observe the appearance of reversed austenite in the material, X-Ray Diffraction technique was used. The electrochemical study was based on the results of the Open Circuit Potential (OCP) and Potentiodynamic Polarization Curves tests. The Rockwell C hardness values of the aged samples were also collected in this work, aiming also to relate these results with the presence of reversed austenite. The results showed that samples submitted to higher aging temperatures showed more intense peaks of reversed austenite, as well as lower hardness values and lower corrosion resistance.