摘要 |
PROBLEM TO BE SOLVED: To obtain a steel having excellent corrosion resistance at a low cost on the surface of a steel base material having a specified componental compsn., by forming a coating layer of a metal whose potential is baser than that of the base material in an aq. soln. environment at a specified thickness. SOLUTION: A steel having a compsn. contg., by weight, 0.01 to 3.0% Si, 0.01 to 3.0% Mn, 0.1 to 9.9% Cr, >3 to 10% Al, and the balance Fe with inevitable impurities in which the content of C is limited to <=0.02%, P to <=0.03%, S to <=0.01% and N to <=0.02% is prepd. The steel is used as a base material, and, on the surface of the base material, a coating layer of a metal whose potential is baser than that of the base material in an aq. soln. environment (aluminum, zinc, chromium, manganese or an alloy essentially consisting of them) is formed at a thickness of 0.5 to 500μm. In this way, the corrosion- resistant steel useful for various corrosive environments including high temp. wet corrosive environment such as the exhaust system of the internal combustion engine of an automobile or the like and a dewing corrosive environment is obtained.
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