Polycrystalline interstitial-free steels were cyclically deformed at constant total strain amplitudes ranging from 0.05 to 0.6%. The transformed speed of loop patches into dislocation cells and walls near grain boundary was faster than that in the grain interior while total strain amplitude was lower than 0.15%. However, the well-known dislocation-free zones near to the grain boundary were very hard to find in this study. Also, dislocation cells tended to transform into loop-patch structures near to the grain boundary during high–low strain-controlled fatigue (two-step) tests.

The Effects of Grain Boundary on Dislocation Development for Cyclically Deformed IF Steel. C.C.Shih, N.J.Ho, H.L.Huang: Materials Science and Engineering A, 2010, 527[27-28], 7247-51