Multiaxial elastoplastic cyclic loading of austenitic 316L steel

V Mazánová,J Polák,V Škorík,T Kruml

doi:10.3221/igf-esis.40.14

Abstract

Cyclic stress-strain response and fatigue damage character has been investigated in austenitic stainless steel 316L. Hollow cylindrical specimens have been cyclically deformed in combined tension-compression and torsion under constant strain rate condition and different constant strain and shear strain amplitudes. In-phase and 90° out-of-phase cyclic straining was applied and the stress response has been monitored. Cyclic hardening/softening curves were assessed in both channels. Cyclic softening followed for higher strain amplitudes by long-term cyclic hardening was observed. Cyclic stress-strain curves were determined. Study of the surface damage in fractured specimens revealed the types and directions of principal cracks and the sources of fatigue crack initiation in slip bands.

Highlights

Cyclic plastic response and damage evolution in elastoplastic cyclic loading of stainless steels, 316L steel, has been studied mostly in tension-compression and in torsion [3] and less frequently in multiaxial loading [4, 5]
The subject of the present contribution is to extend the study of the cyclic plastic response and early fatigue damage to tubular specimens of 316L austenitic steel subjected to cyclic tension-compression and torsion biaxial cyclic loading
Cyclic hardening is followed by mild softening for small strain amplitudes and hardening for high strain amplitudes both in tension-compression and in torsion

Summary

Introduction

Cyclic plastic response and damage evolution in elastoplastic cyclic loading of stainless steels, 316L steel, has been studied mostly in tension-compression (see e.g.[1, 2]) and in torsion [3] and less frequently in multiaxial loading [4, 5]. Multiaxial cyclic loading; 316L steel; Cyclic stress-strain curve; Crack initiation. The localization of the cyclic strain into persistent slip bands (PSBs) influences its cyclic plastic response and results in formation of persistent slip markings (PSMs) in which fatigue cracks initiate. The subject of the present contribution is to extend the study of the cyclic plastic response and early fatigue damage to tubular specimens of 316L austenitic steel subjected to cyclic tension-compression and torsion biaxial cyclic loading.

Results

Conclusion