Hot-dip galvanized steel pipe and method of manufacturing the same
AssigneeNippon Steel & Sumitomo Metal Corporation
InventorsKouichi Okamoto, Hioroshi Takebayashi, Yoshitaka Soga
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Abstract
There are provided a hot-dip galvanized steel pipe in which the plating layer thereof is less liable to peel off even if the steel pipe is worked, and a method of manufacturing the hot-dip galvanized steel pipe. The hot-dip galvanized steel pipe includes a steel pipe and the plating layer formed on the surface of the steel pipe. Throughout the entire depth of plating layer, the fn defined by the following formula is at least 99.9: fn=Fe+Al+Zn where, the symbol of an element in the formula represents the content (mass %) of that element in the plating layer.
Claims3
A hot-dip galvanized steel pipe comprising:
- a steel pipe;
- and
- a plating layer formed on a surface of the steel pipe, wherein
- throughout an entire depth of plating layer, an fn defined by the following formula is at least 99.9:
- fn=Fe+Al+Zn
- where, a symbol of an element in the above formula represents a content in mass % of that element in the plating layer.
A method of manufacturing a hot-dip galvanized steel pipe, comprising a step of dipping a material pipe in a hot-dip galvanizing bath, wherein
- the hot-dip galvanizing bath contains 0.002 to 0.01 mass % of Al, the balance being Zn and impurities, and
- a total content of Pb, Sn, Cd, Sb, Bi, Cu, Ni, and In of the impurities is at most 0.1 mass %.
Dependencies are inferred from the claim text.