Austenitic stainless steels processed by rolling are widespread in technological applications, since they have excellent mechanical and corrosion properties. This study investigated the effect of the cooling rate, microstructure and properties of 316L austenitic stainless steel under cold rolled conditions and by rapid solidification. The microstructure of the cold rolling processing steel was composed of austenite and a low percentage of delta ferrite. For the rapid solidification condition, the microstructure evolved from columnar and acicular dendrites to equiaxed dendrites with decreasing cooling rates, without the presence of delta ferrite due to the high cooling rate. Furthermore, thermal analyses in both routes revealed that oxidation kinetics was slower after rapid solidification in synthetic air. The microhardness in the cold rolling condition was lower than in the rapid solidification condition since the microstructure under the solidification condition is more refined. The sample in the rapid solidification condition region RS1 presented the highest corrosion resistance considering the pit potential. The passivation current density in the cold rolled condition was 5.72x10-5A/cm2, while under the rapid solidification condition, regions RS1 and RS2 were 2.24x10-5 A/cm2 and 3.72x10-6 A/cm2, respectively, and region RS3, did not present a passivation region in a broad range of potentials.

With technological advances in the several areas of knowledge, the constant search for materials with characteristics that meet certain applications has been growing, especially in the chemical and petrochemical industries, where materials capable of withstanding the conditions of corrosion in aggressive environments are required. The aim of this paper was to analyze the influence of the alloy element molybdenum on the microstructure and the resistance to corrosion of two duplex stainless steels identified as A (with molybdenum) and B (without molybdenum), after solution-treated under the following conditions: heating at 1100ºC for 30, 120 and 240 minutes. The steels were characterized by SEM, EDS, DRX and microhardness. The rise in solution treatment time fostered an increase in the volumetric fraction of the ferrite phase, in both steels. The solution treatment at 1100ºC for 120 minutes, for steels A and B, provided good resistance to pit corrosion, as well as the development of a passivating film in the solution of lithium chloride (120,000 ppm of chloride ions).