Steel rod and high strength steel wire having superior ductility and methods of production of same
First Claim
1. A high strength steel wire superior in ductility obtained by a process comprising patenting, then drawing a rolled steel rod having a diameter of 3 to 7 mm for high strength steel wire superior in ductility comprising, by mass % or mass ppm, C:
- 0.80 to 1.20%, Si;
0.1 to 1.5%, Mn;
0.1 to 1.0%, Al;
0.01% or less, Ti;
0.01% or less, W;
0.005 to 0.2%, optionally Mo;
0.003 to 0.2%, N;
10 to 30 ppm, B;
4 to 30 ppm, wherein solute B is 3 ppm or more, O;
10 to 40 ppm, at least one of Cr;
0.5% or less, Ni;
0.5% or less, Co;
0.5% or less, V;
0.5% or less, Cu;
0.2% or less or Nb;
0.1% or less, and a balance of Fe and unavoidable impurities, having an area percentage of pearlite structures of 97% or more, having a balance of non-pearlite structures comprising bainite, degenerated pearlite and proeutectoid ferrite, and having a total of the area percentage of the non-pearlite structures and the area percentage of the coarse pearlite structures where the apparent lamellar spacing is 600 nm or more of 15% or less, wherein said steel wire has a tensile strength of 3600 MPa or more and a number density of voids of lengths of 5 μ
m or more of 100/mm2 or less at the center.
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Accused Products
Abstract
The present invention inexpensively provides with high productivity and good yield a steel rod superior in drawability and a steel wire superior in twistability using the same as a material, that is, draws a high strength steel rod superior in ductility where the chemical components contain C: 0.80 to 1.20%, Si: 0.1 to 1.5%, Mn: 0.1 to 1.0%, Al: 0.01% or less, Ti: 0.01% or less, one or both of W: 0.005 to 0.2% and Mo: 0.003 to 0.2%, N: 10 to 30 ppm, B: 4 to 30 ppm (of which, solute B is 3 ppm or more), and O: 10 to 40 ppm, which has a balance of Fe and unavoidable impurities, has an area percentage of pearlite structures of 97% or more, has a balance of non-pearlite structures, and has a total of the area percentage of the non-pearlite structures and the area percentage of the coarse pearlite structures of 15% or less, to obtain high strength steel wire superior in ductility having a tensile strength of 3600 MPa or more and a number density of voids of lengths of 5 μm or more at the center of 100/mm2 or less.
11 Citations
6 Claims
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1. A high strength steel wire superior in ductility obtained by a process comprising patenting, then drawing a rolled steel rod having a diameter of 3 to 7 mm for high strength steel wire superior in ductility comprising, by mass % or mass ppm, C:
- 0.80 to 1.20%, Si;
0.1 to 1.5%, Mn;
0.1 to 1.0%, Al;
0.01% or less, Ti;
0.01% or less, W;
0.005 to 0.2%, optionally Mo;
0.003 to 0.2%, N;
10 to 30 ppm, B;
4 to 30 ppm, wherein solute B is 3 ppm or more, O;
10 to 40 ppm, at least one of Cr;
0.5% or less, Ni;
0.5% or less, Co;
0.5% or less, V;
0.5% or less, Cu;
0.2% or less or Nb;
0.1% or less, and a balance of Fe and unavoidable impurities, having an area percentage of pearlite structures of 97% or more, having a balance of non-pearlite structures comprising bainite, degenerated pearlite and proeutectoid ferrite, and having a total of the area percentage of the non-pearlite structures and the area percentage of the coarse pearlite structures where the apparent lamellar spacing is 600 nm or more of 15% or less, wherein said steel wire has a tensile strength of 3600 MPa or more and a number density of voids of lengths of 5 μ
m or more of 100/mm2 or less at the center. - View Dependent Claims (2, 3)
- 0.80 to 1.20%, Si;
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4. A high strength steel wire superior in ductility obtained by a process comprising patenting, then drawing a rolled steel rod having a diameter of 3 to 7 mm for high strength steel wire superior in ductility comprising, by mass % or mass ppm, C:
- 0.80 to 1.20%, Si;
0.1 to 1.5%, Mn;
0.1 to 1.0%, Al;
0.01% or less, Ti;
0.01% or less, one or both of W;
0.005 to 0.2% and Mo;
0.003 to 0.2%, N;
10 to 30 ppm, B;
4 to 30 ppm, wherein solute B is 3 ppm or more, O;
10 to 40 ppm, at least one of Cr;
0.5% or less, Ni;
0.5% or less, Co;
0.5% or less, V;
0.5% or less, Cu;
0.2% or less or Nb;
0.1% or less, and a balance of Fe and unavoidable impurities, having an area percentage of pearlite structures of 97% or more, having a balance of non-pearlite structures comprising bainite, degenerated pearlite and proeutectoid ferrite, and having a total of the area percentage of the non-pearlite structures and the area percentage of the coarse pearlite structures where the apparent lamellar spacing is 600 nm or more of 15% or less, wherein said steel wire has a tensile strength of 3600 MPa or more and a number density of voids of lengths of 5 μ
m or more of 100/mm2 or less at the center. - View Dependent Claims (5, 6)
- 0.80 to 1.20%, Si;
Specification
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- Resources
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Current AssigneeNippon Steel Corporation
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Original AssigneeNippon Steel & Sumitomo Metal Corporation (Nippon Steel Corporation)
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InventorsYamasaki, Shingo, Nishida, Seiki
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Primary Examiner(s)Yang, Jie
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Application NumberUS12/452,816Publication NumberTime in Patent Office2,472 DaysField of Search148/599, 148/330, 148/598US Class Current1/1CPC Class CodesB21C 1/003 Drawing materials of specia...C21D 2211/009 PearliteC21D 6/004 containing Cr and NiC21D 6/005 containing MnC21D 6/007 containing CoC21D 6/008 containing SiC21D 8/065 of ferrous alloysC21D 9/525 for wire, for rods C21D9/54...C22C 38/001 containing NC22C 38/002 containing In, Mg, or other...C22C 38/02 containing siliconC22C 38/04 containing manganeseC22C 38/06 containing aluminiumC22C 38/08 containing nickel C22C38/10...C22C 38/10 containing cobaltC22C 38/12 containing tungsten, tantal...C22C 38/14 containing titanium or zirc...C22C 38/16 containing copperC22C 38/20 with copperC22C 38/22 with molybdenum or tungstenView All
