▎ 摘　　要

NOVELTY - A metallic substrate is annealed at an initial temperature of 600-800 degrees C and hydrogen-containing environment to reduce surface oxides on the metallic substrate. The metallic substrate is cooled at a final temperature of 600 degrees C or less for graphene growth. A carbon vapor is provided by decomposing a solid carbon source at 200-400 degrees C and contacted with the metallic substrate at the final temperature to form graphene layer(s) on the metallic substrate. USE - Method of preparing graphene layers on metallic substrate used in anti-corrosion applications for fastener, bolt, screw, washer, nut, latch, threaded rod and threaded insert, of spacecraft, submarine, aircraft, oil tanker, shipping vessel, vehicle, pipeline, sewage pipe, building, furniture, decoration, lighting, furnishing, kitchenware and utensil, and anti-oxidation applications for electronic device and magnetic device, and nanopowder, nanoparticles and nanowires for paint (all claimed). ADVANTAGE - The method is reliable, economical, environmentally-friendly and energy-saving. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) metallic substrate, which comprises one or more graphene layers; and (2) usage method of metallic substrate in anti-corrosion application, paint, and anti-oxidation for electronic device and magnetic device.