Temperature dependent measurement of internal damping of austenitic stainless steels

Monika Oravcová,Mária Chalupová,Milan Uhríčik,Peter Palček,M Vasko,A Sapietová,O Štalmach,V Baniari,P Kopas,M Blatnická,M Sága,M Handrik,L Jakubovičová

doi:10.1051/matecconf/201815707008

Abstract

This article is aimed on the analysis of the internal damping changes of austenitic stainless steels AISI 304, AISI 316L and AISI 316Ti depending from temperature. In experimental measurements only resonance method was used which is based on continuous excitation of oscillations of the specimens and the whole apparatus vibrates at the frequency near to the resonance. Microplastic processes and dissipation of energy within the metals are evaluated and investigated by internal damping measurements. Damping capacity of materials is closely tied to the presence of defects including second phase particles and voids. By measuring the energy dissipation in the material, we can determine the elastic characteristics, Youngs modulus, the level of stress relaxation and many other.

Highlights

Austenitic stainless steels are a class of alloys with a face-centered-cubic lattice structure of austenite which maintains from room temperature to the melting point
These graphs contains the second measurement of internal damping, on the same samples, where not such a high peak was observed as in the first measurement
Further heating above 400 °C was not necessary because all the processes has taken place in the temperature range of 25-100 °C. After this interval there is a steep decline of internal damping and after 200 °C the values of internal damping change only a little

Summary

Introduction

Austenitic stainless steels are a class of alloys with a face-centered-cubic lattice structure of austenite which maintains from room temperature (and below) to the melting point. When 18% chromium and 8% nickel are added, the crystal structure of austenite remains stable over all temperatures. They are the most widely used grade of stainless steel. These steels have a very good mechanical and technological properties finding widespread in industrial, chemical and food applications, and in medical field. They are corrosion resistant, paramagnetic in the annealed condition, they can become slightly magnetic after plastic deformation, e.g. after cold working [1, 2]. A material's microchemistry may be changed during thermomechanical processing and its functional properties are changed

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Conclusion