Effect of the Temperature in the Mechanical Properties of Austenite, Ferrite and Sigma Phases of Duplex Stainless Steels Using Hardness, Microhardness and Nanoindentation Techniques
Gorka Argandoña,
José F. Palacio,
Carlos Berlanga,
María V. Biezma,
Pedro J. Rivero,
Julio Peña,
Rafael Rodriguez
Affiliations
Gorka Argandoña
Multidisciplinary Centre of Technologies for Industry (CEMITEC), Polígono Mocholí, Noain, 31110 Pamplona, Spain
José F. Palacio
Centre of Advanced Surface Engineering, AIN, Cordovilla, 31191 Pamplona, Spain
Carlos Berlanga
Materials Engineering Laboratory, Department of Mechanical, Energetic and Materials Engineering, Public University of Navarre, Campus Arrosadía S/N, 31006 Pamplona, Spain
María V. Biezma
Department of Earth, Materials Science and Engineering, University of Cantabria, 39004 Santander, Spain
Pedro J. Rivero
Materials Engineering Laboratory, Department of Mechanical, Energetic and Materials Engineering, Public University of Navarre, Campus Arrosadía S/N, 31006 Pamplona, Spain
Julio Peña
Multidisciplinary Centre of Technologies for Industry (CEMITEC), Polígono Mocholí, Noain, 31110 Pamplona, Spain
Rafael Rodriguez
Materials Engineering Laboratory, Department of Mechanical, Energetic and Materials Engineering, Public University of Navarre, Campus Arrosadía S/N, 31006 Pamplona, Spain
The aim of this work is to study the hardness of the ferrite, austenite and sigma phases of a UNS S32760 superduplex stainless steel submitted to different thermal treatments, thus leading to different percentages of the mentioned phases. A comparative study has been performed in order to evaluate the resulting mechanical properties of these phases by using hardness, microhardness and nanoindentation techniques. In addition, optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) have been also used to identify their presence and distribution. Finally, the experimental results have shown that the resulting hardness values were increased as a function of a longer heat treatment duration which it is associated to the formation of a higher percentage of the sigma phase. However, nanoindentation hardness measurements of this sigma phase showed lower values than expected, being a combination of two main factors, namely the complexity of the sigma phase structure as well as the surface finish (roughness).
