| 摘要 |
PROBLEM TO BE SOLVED: To prevent corrosion even with high temperature status with temperature of molten salt of over 600°C when using the molten salt as heat medium.SOLUTION: A tube member for solar heat collection tube 11 is manufactured by a centrifugal casting process and a pure nickel layer 13 is formed at an inner surface of a cylindrical body 12 formed by low nickel heat resistant cast iron. The low nickel heat resistant cast iron consists of a basic elements consisting of carbon (C), silicon (Si), chromium (Cr), nickel (Ni), manganese (Mn) and copper (Cu) and the balance iron (Fe) with inevitable impurities and trace quantity element of 1 mass% or less based on 100 mass% of whole cast iron, is structured by a matrix consisting of an Fe alloy having an austenite phase as a main phase at room temperature and Nickel (Ni) is 7 to 22 mass% based on 100 mass% of whole cast iron.SELECTED DRAWING: Figure 1 |
