NOVELTY - The method involves plating a heat transfer tube with nickel (Ni) or nickel alloy. Nickel plating or nickel alloy plating is partially or entirely conducted on an inner or outer surface of the heat transfer tube. The heat transfer tube is expanded after plating with the nickel or alloy. Expansion of the heat transfer tube plated with the nickel or alloy is performed by a mechanical expansion process, an explosion expansion process or a hydraulic expansion process. The alloy is selected from a group consisting of nickel-phosphorus, nickel-ferrous iron-phosphorus and nickel-phosphorus-born.    USE - Method for preventing corrosion such as a pitting corrosion, abrasion, stress corrosion cracking, and lead-induced stress corrosion cracking, degradation in a heat transfer tube of a steam generator that is utilized in nuclear power plant, hydroelectrical power plant, thermoelectric power plant or petrochemical plant (all claimed), of a defense industry.    ADVANTAGE - The method improves life span of a steam generator, and reduces maintenance cost. The method increases operation rate of the nuclear power plant, and decreases unit cost of the production of electric power, thus improving economic efficiency. The method prevents leakage problems in the heat transfer tube of the steam generator. The method prevents vibration of the heat transfer tube caused by flow of fluid. The method removes sludge during operation of the nuclear power plant, and reduces enormous economic loss. The method prevents occurrence of the accident, and prevents deterioration occurrence of different materials. The method reduces corrosion current density. The method prevents that corrosion degradation is continuously exerted. The method realizes excellent mechanical properties, and prevents primary cooling water contaminated by radioactivity.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a scanning electron micrograph showing a nickel-plated heat transfer tube of a steam generator.