Strain-hardening characteristics of ferrite layers in pearlite microstructure

Strain hardening of ferrite layers in pearlite microstructures plays a crucial role in the stability of elasto-plastic deformation of pearlite. The effects of layer thickness, crystal orientation relationship and loading direction on the strain-hardening characteristics of the ferrite layers were studied by crystal plasticity analysis. The results show that the strain-hardening rate increases in the ferrite layers with small thickness, whereas at the same thickness, the strain-hardening rate varies depending on the loading direction and crystal orientation relationship. When the Schmid factors and mean-free paths of the activated systems are small and short, the strain-hardening rate tends to be high. The ferrite layer exhibits a remarkably high strain-hardening rate when slip systems are sequentially activated with the increase of deformation.