Steel wire material and method for manufacturing same
AssigneeKabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
InventorsMikako Takeda, Shohei Nakakubo, Kazuhiko Kirihara, Masayuki Endo
Life of this patent
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Abstract
This steel wire material contains 0.05%-1.2% C (“%” means “% by mass,” same hereinafter for chemical components.), 0.01%-0.7% Si, 0.1%-1.5% Mn, 0.02% max. P (not including 0%), 0.02% max. S (not including 0%), and 0.005% max. N (not including 0%), with the remainder being iron and unavoidable impurities. The steel wire material has a scale 6.0-20 μm thick and holes of an equivalent circle diameter of 1 μm max. in said scale that occupy 10% by area max. Said scale does not detach in the cooling process after hot rolling or during storage or transportation but can readily detach during mechanical descaling.
Claims10
A steel wire material, comprising:
- C in a content by mass of from 0.05 to 1.2%;
- Si in a content by mass of from 0.01 to 0.7%;
- Mn in a content by mass of from 0.1 to 1.5%;
- P in a content by mass of greater than 0% and no more than 0.02%;
- S in a content by mass of greater than 0% and no more than 0.02%;
- N in a content by mass of greater than 0% and no more than 0.005%;
- and
- a remainder of iron and unavoidable impurities,
- wherein a scale on a surface of the wire material has a thickness of 6.0 μm or more and 20 μm or less, and
- holes of an equivalent circle diameter of 1 μm or less are 10% or less by area of the scale.
A method for manufacturing a steel wire material, the method comprising:
- hot rolling steel of a chemical composition at a rolling finish temperature of from 1,000 to 1,100° C., thereby obtaining a hot rolled steel;
- cooling the hot rolled steel by contacting a non-oxygen medium with the hot rolled steel, thereby obtaining a cooled steel;
- and
- winding the cooled steel at a winding temperature of from 750 to 950° C.,
- wherein, in the cooling from the rolling finish temperature to the winding temperature, a residence time at a temperature of 950° C. or above is from 0.20 to 20 s and a residence time at a temperature of 950° C. or below is less than 0.15 s, and
- the chemical composition comprises C in a content by mass of from 0.05 to 1.2%, Si in a content by mass of from 0.01 to 0.7%, Mn in a content by mass of from 0.1 to 1.5%, P in a content by mass of greater than 0% and no more than 0.02%, S in a content by mass of greater than 0% and no more than 0.02%, N in a content by mass of greater than 0% and no more than 0.005%, and a remainder of iron and unavoidable impurities.
Dependencies are inferred from the claim text.