Effect of surface nanocrystallization on the tribological properties of 1Cr18Ni9Ti stainless steel

Surface nanocrystallization of 1Cr18Ni9Ti austenite stainless steel was conducted by the supersonic fine particles bombarding (SFPB) technique. The friction coefficients and wear losses in air and vacuum were tested to analyse the effect of surface nanocrystallization on the tribological properties of 1Cr18Ni9Ti steel. The results show that the microstructure of the surface layer was refined into nano-grains successfully by SFPB treatment; furthermore, strain-induced martensitic transformation occurred during the treatment. The tribological properties of SFPB treated samples enhanced greatly, The dominant wear mechanism of the original 1Cr18Ni9Ti stainless steel is abrasive wear and adhesive wear, while it transfers to the combined action of fatigue wear, abrasive wear and adhesive wear after surface nanocrystallization by SFPB.

Research Highlights
► A nanocrystalline surface layer was fabricated on the 1Cr18Ni9Ti stainless steel by the supersonic fine particles bombarding (SFPB) technology.
► The SFPB treatment induced grain refinement and martensitic phase transformation in the top surface layer.
► The increase of hardness and surface activity of stainless steel after SFPB treatment can enhance its tribological properties notably.
► The dominant wear mechanism of the original 1Cr18Ni9Ti steel are abrasive wear and adhesive wear, while it transfers to the combined action of fatigue wear, abrasive wear and adhesive wear after surface nanocrystallization by SFPB.