| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel product for a boiler non-flame exposure part capable of extending a service period. SOLUTION: The surface of a steel product 6 arranged at a non-flame exposure part is coated by undercoating paint where aluminium powder, silicone resin varnish, a solvent, and an additive are mixed together such that aluminium powder is contained and a ratio of aluminum to resin is adjusted to 1.7 or more to form a high temperature resisting oxidized covering film lower layer 7. Over coating paint where aluminium paste, silicone resin varnish, a solvent, and an additive are mixed together such that aluminium paste is contained and a ratio of aluminum to resin is adjusted to 0.7 or more, and a high temperature resisting oxidized covering film upper layer 8 is coated on the surface of the high temperature resisting oxidized film lower layer 7. By aluminium contained in the covering film lower layer 7 and the covering film upper layer 8, penetration of oxygen into a steel product 6 surface from atmosphere gas is delayed and oxidation of the steel product 6 is suppressed.
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