A UNS S32205 duplex stainless steel was processed by ECAE in three different velocities, at room temperature, and heat treated in different temperatures and times to evaluate recrystallization. Attrition forces promoted great deformation heterogeneity in the samples sections, with hardness increase, and morphology changes in the grains and changing orientation through the processed samples. In treated samples surface, two types of distinct structures was formed, with surfaces positioned in 90º and 120º angles, probably because the annihilation of pilled dislocations in ferrite based centered cubic structure and austenite face centered cubic structure, respectively. The induced martensite by cold deformation was also observed. Some samples demonstrate located points of recrystallization in grain boundaries for some treatment conditions, the number of recrystallization nuclei increased with the increase of treatment time.Keywords: Duplex, ECAP, stainless steel. INTRODUCTIONAlthough the physical and mechanical properties of metals are determined by several factors, the grain size of the material is generally very significant and frequently a dominant factor in determining the properties and final application of the materials [1].The fact of the mechanical resistance increases with the grain size reduction makes interesting the production of materials with an extremely small grain size. Commercial metallic alloys are generally produced for specific applications where the alloys are submitted to specific mechanical and thermal processes. However this procedures can't be used to produce sub micrometric grain sized materials, because they presents a lower limit fixed, in order of a few micrometers, which represents the minimum grain size that can be obtained by these processes [1].To produce ultrafine grained materials by a coarse grained material, the imposture of an extreme high strain is necessary, in order to introduce a high density of dislocations, then these dislocations can be rearranged and form ordered grain boundaries. However, in practice, this situation is restrict in conventional conformation process, like the extrusion or stretching, it happens cause of this two reasons: the total strain that can be imposed to the material is limited by the cross sectional reduction in the specimen, and, the total strain imposed is insufficient to introduce an ultrafine grain structure to the material, due the low workability of these materials at room temperature.Considering these limitations, several researches have been directed to the development of new techniques that can be used to produce ultrafine grained materials and provide the understanding of the behavior during the recrystallization process. Between these techniques, the ECAE (equal channel angular extrusion) was developed, or ECAP (equal channel angular pressing). The principle of ECAE is based on severe plastic deformation application, through the imposture of an extremely high strain in a relatively low temperature, without any significant change...
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