Interstitial free steels with various grain sizes and textures were prepared by cold-rolling followed by an annealing process. The effect of grain size, crystallographic orientations and stored energy on corrosion behavior of interstitial free steel was investigated. It was found that the deformed microstructure and dislocation boundaries were consumed by recrystallizing grains during annealing. The average grain size increase ranging from 0.61 μm to 11 μm and the volume fraction of recrystallized grains was about 96% after annealing for 64 h; meanwhile, the γ fiber was the dominated recrystallized texture component. The stored energy gradually decreased due to the reduction in dislocation density by annealing. The potentiodynamic polarization and Nyquist plots show that the corrosion potential exhibits a more positive shift and depressed capacitive semicircle radius increase with rising annealing time. The 64 h annealed specimens had the biggest depressed semicircle in the Nyquist plots and the highest positive corrosion potential, which indicates the enhancement of corrosion resistance. Such an improvement of corrosion resistance is attributed to the increase in the volume fraction of the γ fiber and decrease in the stored energy.

Homogeneous dispersed RGO/TiO₂ nanocomposite was synthesized using precursors of graphene oxide (GO) and Ti(SO₄)₂ and reducing agent of urea solvent by situ hydrothermal reduction method. The X-ray diffractometer (XRD) and fourier transform-infrared (FTIR) spectra were used to characterize the microstructure of RGO/TiO2 nanocomposite, and transmission electron microscope (TEM) and fieldemission scanning electron microscope (FESEM) were used observe the microtopography of RGO/TiO₂ nanocomposite. The effect of urea mass ratio on number of TiO₂ in RGO/TiO₂ nanocomposite was investigated. It is revealed that the TiO2 nanoparticles efficiently disperse on the surface of RGO (reduced graphene oxide) sheets and RGO/TiO₂ has close interfacial contact.