Influence of the pulsed plasma treatment on the corrosion resistance of the low-alloy steel plated by Ni-based alloy

摘要

This paper presents investigation results of the influence of high temperature pulsed plasma flows (HTPPF) treatment on the corrosion resistance of low-alloy steel 0.2C-Cr-Mn-Ni-Mo cladded by the rapidly quenched nickel-based alloy. A technique that allows obtaining a defect-free clad layer with a good adhesion to the substrate was developed. It is shown that the preliminary treatment of steel samples by nitrogen plasma flows significantly increases their corrosion resistance in the conditions of intergranular corrosion test in a water solution of sulfuric acid. A change of the corrosion mechanism of the clad layer from intergranular to uniform corrosion was observed as a result of sub-microcrystalline structure formation and homogeneous distribution of alloying elements in the plasma treated surface layer thus leading to the significant increase of the corrosion resistance.