A ferritic heat-resistant steel, which exhibits excellent creep characteristics even at a high temperature exceeding 600.degree. C., comprises, on the basis of percent by weight, 1.0 to 13% of chromium, 0.1 to 8.0% of cobalt, 0.01 to 0.20% of nitrogen, 3.0% or less of nickel, 0.01 to 0.50% of one or more of elements selected from a group consisting of vanadium, niobium, tantalum, titanium, hafnium, and zirconium that are MX type precipitate forming elements, and 0.01% or less of carbon and a balance being substantially iron and inevitable impurities, wherein the MX type precipitates precipitate on grain boundaries and in entire grains and the grain boundary existing ratio of an M.sub.23C.sub.6 type precipitate precipitating on the grain boundaries is 50% or less.

 
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> Aluminum alloy piping material for automotive tubes having excellent corrosion resistance and formability, and method of manufacturing same

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