Nanostructured coatings for corrosion protection in reprocessing plants

Abstract

The main process medium in the reprocessing industry is highly oxidizing nitric acid ranging from dilute to concentrated solutions containing fission products and from room temperature to boiling conditions. Corrosion resistance of materials chosen for reprocessing plants is of prime importance for uninterrupted operation. Surface modification and coatings can significantly improve the corrosion resistance of materials. A number of surface modification and coating development works such as double oxide coating on Ti for reconditioning (DOCTOR); mixed oxide coated Ti anodes (MOCTAs); nanostructured Ti, TiO2, TiN, and ZrN; bulk metallic glasses (BMGs); and superhydrophobic (SHB) coatings for corrosion protection are being pursued in our laboratory. Nanostructured coatings developed on Ti-like DOCTOR and MOCTAs showed improved corrosion resistance and longer life. Nanostructured Ti, TiO2, and ZrN coatings deposited on type 304L stainless steel (SS) by magnetron sputtering technique and Zr-based bulk metallic Zr59Ti3Cu20Al10Ni8 alloy deposited on type 304L SS by pulsed laser deposition (PLD) technique showed improved corrosion resistance in nitric acid. SHB coating on 9Cr-1Mo and Ti lead to improved corrosion resistance and biofouling resistance of Ti. The surface modification and coating development carried out in our laboratory for corrosion protection in reprocessing plants are briefly highlighted.