LAUSR

50CrVA spring steel is a kind of advanced spring steel and often used as materials of weight valves, safety valve and piston, etc. 50CrVA spring steel has high fatigue strength, high yield-stress ratio, and high harden ability. The heating temperature of 50CrVA spring steel in furnace is below 1 100°C. Decarburization and oxidation of spring steels often were observed along with the heat treatment procedures, especially in O2, CO2, H2O and H2 atmosphere. Decarburization is loss of carbon elements from the surface of substrates, and resulted in changes of mechanical properties, e.g., along with the changes of fatigue resistance and hardness.1) Some traditional methods had been used to reduce the decarburization and oxidation during high temperature treatment of high carbon steel, e.g., drawing and peeling methods as physical ones, vacuum heating and controlling the atmosphere, etc.2) Although these mentioned above methods were efficient in preventing the oxidation and decarburization to some extent, they were restricted in their application because of complex process, high equipment cost, and the rigid operation conditions. Compared with the aforementioned methods, coating method could be suitable for annealing and reheating process at high temperature. Many works devoted to the protective coatings of steel at high temperature.3–6) Low carbon steel, high carbon steel, stainless steel, multi-alloyed steel, and so on was protected by metallic coatings.7–9) The most used methods of applying metallic coatings to steels are thermal spray, hot-dip galvanizing, chemical vapour Corrosion Resistant of Inorganic Coating for 50CrVA Spring Steel at Elevated Temperatures