Steel structures and method anticorrosive coating was Al alloy coating

PROBLEM TO BE SOLVED: To provide a method of inexpensively and sufficiently performing corrosion prevention of a complicated part of a steel structure on which mill coating is impossible. SOLUTION: The corrosion protection method of a steel structure includes subjecting the steel structure to underecoating treatment to achieve a cleanliness equivalent to class 2 cleaning, then coating the class structure with atmospheric plasma thermal spraying so as to form a coated film having a thickness of 100 μm or more, using any of Al having a purity of 99.5 mass% or more, an Al alloy containing 1-5 mass% of Mg, or an Al alloy containing 1-1.5 mass% of Mn, and then subjecting the coated steel structure to sealing treatment using a material essentially comprising a metal alkoxide. COPYRIGHT: (C)2010,JPO&INPIT