Influence of different methods of surface treatment on corrosion resistance of low-alloy steel

Abstract

The influence of mechanical methods of surface treatment (polish and polish with the next strengthening by high-frequency mechanical pinning, HFMP) on the corrosion resistance of low-alloy steel 15HSND were presented. The deficiencies of surface strengthening by HFMP with one impact peen were analyzed, and an instrument in which shock elements are situated in a few rows was suggested. Speed of HFMP for the surfaces 35 sm2/min was recommended. The differences in structure and microhardness of near-surface layers of 15HSND steel with polished surface and the polished surface with next strengthening by HFMP were established after investigations in the salt frog chamber and moisture chamber during 1200 hours. Application of HFMP technology increases of corrosion resistance of steel: corrosion rate after neutral salt fog decreased from 2,543 mm/year on the polished surface to 2,096 mm/year after HFMP treatment, and after increased humidity and temperature, from 0,104 mm/year to 0,080 mm/year.