Residual stress field in steel samples during plastic deformation and recovery processes

Abstract

An X-ray diffraction method was applied to measure residual stresses and stored elastic energy in deformed and annealed polycrystalline ferritic and austenitic steel samples. The orientation distribution of plastic incompatibility second-order stresses created during elastoplastic deformation was determined and presented in Euler space. Using deformation models, these stresses were correlated with different types of intergranular interactions occurring in the studied materials. An important decrease of the first- and the second-order residual stresses was observed during recovery and recrystallisation processes. Diffraction peak widths, related to dislocation density, were studied and correlated with stress variation during annealing process. Differences in stress relaxation between ferritic and austenitic samples were explained by different values of the stacking fault energy, which influences dislocation climb and cross-slip.

Keywords:

• X-ray diffraction
• residual stress
• stacking fault energy
• plasticity
• deformation model
• recovery
• recrystallisation

Acknowledgements

This work was supported by the Polish Ministry of Science and Higher Education (MNiSW), by Polonium Project (7827/R09/R10) and by the Grant No: 712/N-POLONIUM/2010/0.