In practice, composite electrolytic coatings based on chromium and nickel are widely used as protective coatings. The aim of our investigation is to study the influence of thermal treatment on the corrosion resistance of composite electrolytic coatings. Before testing, we classified specimens into three batches. Specimens not subjected to thermal treatment belong to the first batch. Specimens of the second and third batches were thermally treated in argon at a temperature of 1323 K for 3 and 6 h, respectively. We measured the electrode potential-time dependence with a P-58-27M potentiostat in a 3% sodium chloride solution and carried out potentiostatic tests in the range of potential 0.04-0.05 V with an exposure time of 2-5 min.