The Cavitation Erosion of the 45# Carbon Steels Implanted with Titanium and Nitrogen

Abstract

The polished 0.45%-C steels (45# carbon steels) were implanted with titanium (Ti), nitrogen (N), and titanium/nitrogen (Ti/N) ions at fluence of 2 × 10 ¹⁷ ions/cm ² , 2 × 10 ¹⁷ ions/cm ² , and 4 × 10 ¹⁷ ions/cm ² , respectively. To evaluate the cavitation erosion resistances of the ion-implanted 45# steel samples, the cavitation erosion experiments were carried out by using a rotating-disk facility. The surface nanohardness and the polarization potentials corresponding to the ion-implanted samples were also investigated by using a nano-indentation tester and electrochemical techniques. The results showed that relative to the initial 45# steel, the surface nanohardness and the polarization potentials corresponding to the ion-implanted 45# steel samples all increase to varying degrees. The cavitation erosion resistances corresponding to these ion-implanted samples are enhanced with the increase of their polarization potentials. To elucidate the cavitation erosion mechanism of the ion-implanted 45# steel samples, the phase structures and the electronic structures of the steel samples implanted with Ti, N, and Ti/N were studied by using X-ray diffraction and X-ray photoelectron spectroscopy. The results indicated that the ion implantation alters the structure of the 45# steel and that new phases form. The new phases are the domination factors that have contributions to the improvements of the cavitation erosion resistance of the samples.

KEY WORDS:

• Cavitation Erosion
• Carbon Steel
• Surface Modification

ACKNOWLEDGMENTS

This work was supported by the NSFC Project under grants 50675112 and 20703029 and by the National Basic Research Program of China under grant 2007CB707702.

Review led by Al Segall