In the current work a nano-crystalline Ni-20Cr coating was developed on a boiler tube material by cold-spray process. The coating powder was synthesized in-house by mechanical milling using a planetary ball mill. The average crystallite size of the developed powder was calculated to be 10 nm. The crystallite size of the coating was found to be 18 nm, and hence the retention of nano-crystallinity in the coating was established. However the grain growth occurred to some extent, which may be due to temperature rise involved in the cold spray process. A detailed TEM analysis of coated samples before and after exposure to high temperature oxidation was carried out.