Wear and corrosion resistance behavior of Zr-2.5Nb by pack carburizing and boronizing

Abstract

In this work, carbonized and boronized layers of 4–9 μm were prepared by high temperature pack carburizing and boronizing in Zr-2.5Nb alloys, respectively. Differences in phase composition, elemental distribution, wear resistance and corrosion resistance between carburized and boronized layers were compared. The results showed that the carbonized layer was mainly composed of ZrC and NbC, and the boronized layer was composed of ZrC and ZrB2. Both carburizing and boronizing treatments enlarged the corrosion potential in 3.5 % Nacl and 5 % HCl solutions, and the pitting potential is also higher than that of the substrate sample. Among all the treated samples, the 1000 °C-C1 sample had the lowest corrosion current density of 9.81 × 10−6 A/cm2 in 3.5 % NaCl solution, but they are all slightly higher than substrate. And their wear volume was only 16 % -50 % of that of the substrate.