High-carbon steel wire rod with excellent wire drawability
AssigneeNippon Steel & Sumitomo Metal Corporation
InventorsMakoto OKONOGI, Daisuke HIRAKAMI
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Abstract
Provided is a high-carbon steel wire rod with excellent wire drawability, containing predetermined chemical components and the balance: Fe and impurities. In a cross-section perpendicular to a longitudinal direction, an area fraction of pearlite is equal to or more than 95% and equal to or less than 100%, an average block size of the pearlite is 10 μm to 30 μm and standard deviation of block size is 20 μm or less, and when Ceq.=C (%)+Si (%)/24+Mn (%)/6, a tensile strength is equal to or more than 760×Ceq.+255 MPa and equal to or less than 760×Ceq.+325 MPa, reduction of area in a tensile test is −65×Ceq.+96(%) or more, and standard deviation of the reduction of area is 6% or less.
Claims2
A high-carbon steel wire rod with excellent wire drawability, comprising chemical components of, in mass %,
- C:
- 0.70% to 1.20%,
- Si:
- 0.10% to 1.2%,
- Mn:
- 0.10% to 1.0%,
- P:
- 0.001% to 0.012%,
- S:
- 0.001% to 0.010%,
- N:
- 0.0010% to 0.0050%, and
- the balance:
- Fe and impurities,
- wherein in a cross-section perpendicular to a longitudinal direction, an area fraction of pearlite is equal to or more than 95% and equal to or less than 100%,
- an average block size of the pearlite is 10 μm to 30 nm, and standard deviation of block size is 20 μm or less, and
- when Ceq. is obtained using formula (1) below, a tensile strength is equal to or more than 760×Ceq.+255 MPa and equal to or less than 760×Ceq.+325 MPa, reduction of area in a tensile test is −65×Ceq.+96(%) or more, and standard deviation of the reduction of area is 6% or less,
- Ceq.=C (%)+Si (%)/24+Mn (%)/6 formula (1),
- where C (%), Si (%), and Mn (%) represent contents in mass % of C, S, and Mn, respectively.
Dependencies are inferred from the claim text.