Abstract: A predetermined composition is had, when a C content is represented by (C %), in a case of (C %) being not less than 0.35% nor more than 0.65%, a volume fraction of pearlite is 64×(C %)+52% or more, and in a case of (C %) being greater than 0.65% and 0.85% or less, the volume fraction of pearlite is not less than 94% nor more than 100%, and a structure of the other portion is composed of one or two of proeutectoid ferrite and bainite. Further, in a region to a depth of 1.0 mm from a surface, a volume fraction of pearlite block having an aspect ratio of 2.0 or more is not less than 70% nor more than 95%, and a volume fraction of pearlite having an angle between an axial direction and a lamellar direction on a cross section parallel to the axial direction of 40° or less is 60% or more with respect to all pearlite.

Abstract: A predetermined composition is had, when a C content is represented by (C %), in a case of (C %) being not less than 0.35% nor more than 0.65%, a volume fraction of pearlite is 64×(C %)+52% or more, and in a case of (C %) being greater than 0.65% and 0.85% or less, the volume fraction of pearlite is not less than 94% nor more than 100%, and a structure of the other portion is composed of one or two of proeutectoid ferrite and bainite. Further, in a region to a depth of 1.0 mm from a surface, a volume fraction of pearlite block having an aspect ratio of 2.0 or more is not less than 70% nor more than 95%, and a volume fraction of pearlite having an angle between an axial direction and a lamellar direction on a cross section parallel to the axial direction of 40° or less is 60% or more with respect to all pearlite.

Abstract: A predetermined composition is had, when a C content is represented by (C %), in a case of (C %) being not less than 0.35% nor more than 0.65%, a volume fraction of pearlite is 64×(C %)+52% or more, and in a case of (C %) being greater than 0.65% and 0.85% or less, the volume fraction of pearlite is not less than 94% nor more than 100%, and a structure of the other portion is composed of one or two of proeutectoid ferrite and bainite. Further, in a region to a depth of 1.0 mm from a surface, a volume fraction of pearlite block having an aspect ratio of 2.0 or more is not less than 70% nor more than 95%, and a volume fraction of pearlite having an angle between an axial direction and a lamellar direction on a cross section parallel to the axial direction of 40° or less is 60% or more with respect to all pearlite.

Abstract: A wire material used for manufacturing a non-heat treated component whose tensile strength is 900 MPa to 1300 MPa, containing, in mass %: C: 0.20% to 0.50%, Si: 0.05% to 2.0%, Mn: 0.20% to 1.0%, being limited to contain P: 0.030% or less, S: 0.030% or less, N: 0.005% or less, F1 defined by the following expression (1) is less than 0.60, with the balance made up of Fe and inevitable impurities, wherein a metal structure contains a pearlite structure of 64×(C %)+52% or more in a volume fraction, with the balance made up of one kind or two kinds of a pro-eutectoid ferrite structure and a bainite structure, an average block grain diameter of the pearlite structure at a region from a surface layer to 0.1 D is 15 ?m or less when a diameter of the wire material is set to be D, and (the average block grain diameter of the pearlite structure at the region from the surface layer to 0.1 D)/(an average block grain diameter of the pearlite structure at a range from 0.25 D to a center) is less than 1.0.

Abstract: A wire material used for manufacturing a non-heat treated component whose tensile strength is 900 MPa to 1300 MPa, containing, in mass %: C: 0.20% to 0.50%, Si: 0.05% to 2.0%, Mn: 0.20% to 1.0%, being limited to contain P: 0.030% or less, S: 0.030% or less, N: 0.005% or less, F1 defined by the following expression (1) is less than 0.60, with the balance made up of Fe and inevitable impurities, wherein a metal structure contains a pearlite structure of 64×(C %)+52% or more in a volume fraction, with the balance made up of one kind or two kinds of a pro-eutectoid ferrite structure and a bainite structure, an average block grain diameter of the pearlite structure at a region from a surface layer to 0.1 D is 15 ?m or less when a diameter of the wire material is set to be D, and (the average block grain diameter of the pearlite structure at the region from the surface layer to 0.1 D)/(an average block grain diameter of the pearlite structure at a range from 0.25 D to a center) is less than 1.0.

Abstract: A predetermined composition is had, when a C content is represented by (C %), in a case of (C %) being not less than 0.35% nor more than 0.65%, a volume fraction of pearlite is 64×(C %)+52% or more, and in a case of (C %) being greater than 0.65% and 0.85% or less, the volume fraction of pearlite is not less than 94% nor more than 100%, and a structure of the other portion is composed of one or two of proeutectoid ferrite and bainite. Further, in a region to a depth of 1.0 mm from a surface, a volume fraction of pearlite block having an aspect ratio of 2.0 or more is not less than 70% nor more than 95%, and a volume fraction of pearlite having an angle between an axial direction and a lamellar direction on a cross section parallel to the axial direction of 40° or less is 60% or more with respect to all pearlite.

Abstract: This invention provides high-carbon steel wire rod and wire excellent in drawability and methods of producing the same.The high-carbon steel wire rod or wire is characterized in that it contains, in weight percent, C: 0.90-1.10%, Si: not more than 0.40% and Mn: not more than 0.50%, is limited to P: not more than 0.02%, S: not more than 0.01% and Al: not more than 0.003%, the remainder being Fe and unavoidable impurities, and has a microstructure of, in terms of area ratio, not less than 80% upper bainite texture obtained by two-stepped transformation and an Hv of not more than 450. The high-carbon steel wire rod or wire may additionally contain Cr: 0.10-0.30% as an alloying component.

Abstract: This invention provides bainite wire rod and wire excellent in drawability and methods of producing the same.The bainite wire rod or wire is characterized in that it contains, in weight percent, C : 0.90-1.10%, Si : not more than 0.40% and Mn : not more than 0.50%, if required contains Cr : 0.10-0.30%., and is limited to Al : not more than 0.003%, P : not more than 0.02% and S : not more than 0.01%, the remainder being Fe and unavoidable impurities, and has tensile strength and reduction of area determined by the following equations (1) and (2),TS.ltoreq.85.times.(C)+60 (1)RA.gtoreq.-0.875.times.(TS)+158 (2)whereC : carbon content (wt %),TS : tensile strength (kgf/mm.sup.2), andRA : reduction of area (%).

Abstract: This invention provides bainite wire rod and wire excellent in drawability and methods of producing the same.The bainite wire rod or wire is characterized in that it contains, in weight percent, C: 0.80-0.90%, Si: 0.10-1.50% and Mn: 0.10-1.00%, if required contains Cr: 0.10-1.00%, and is limited to P: not more than 0.02%, S: not more than 0.01% and A1: not more than 0.003%, the remainder being Fe and unavoidable impurities, and has tensile strength and reduction of area determined by the following equations (1) and (2),TS.ltoreq.85.times.(C)+60 (1)RA.gtoreq.-0.875.times.(TS)+158 (2)whereC: carbon content (wt%),TS: tensile strength (kgf/mm.sup.2), andRA: reduction of area (%).

Abstract: This invention relates to high-carbon steel wire rod and wire excellent in drawability and methods of producing the same.The high carbon steel wire rod or wire excellent in is characterized in that it contains, in weight percent, C: 0.70-1.20%, Si: 0.15-1.00% and Mn: 0.30-0.90%, further contains as alloying components one or both of Al: 0.006-0.100 and Ti: 0.01-0.35%, is limited to P: not more than 0.02% and S: not more than 0.01%, the remainder being Fe and unavoidable impurities, and has a microstructure of, in terms of area ratio, not less than 80% upper bainite texture obtained by two-stepped transformation and an Hv of not more than 450. The high-carbon steel wire rod or wire may additionally contain Cr: 0.10-0.50% as an alloying component.

Abstract: This invention relates to high-carbon steel wire rod and wire excellent in drawability and methods of producing the same.The high carbon steel wire rod or wire excellent in is characterized in that it contains, in weight percent, C: 0.80-0.90%, Si: 0.10-1.50% and Mn: 0.10-1.00, is limited to P: not more than 0.02%, S: not more than 0.01% and Al: not more than 0.003%, the remainder being Fe and unavoidable impurities, and has a microstructure of, in terms of area ratio, not less than 80% upper bainite texture obtained by two-stepped transformation and an Hv of not more than 450. The high-carbon steel wire rod or wire may additionally contain Cr: 0.10-1.00% as an alloying component.The high-carbon steel wire rod or wire according to this invention can be drawn to an appreciably higher reduction of area than prior art products and also has improved delamination resistance property.

Abstract: This invention provides bainite wire rod and wire excellent in drawability and methods of producing the same.The bainite wire rod or wire is characterized in that it contains, in weight percent, C: 0.70-1.20%, Mn: 0.30-0.90% and Si: 0.15-1.00%, further contains as alloying components one or both of Al: 0.006-0.100% and Ti: 0.01-0.35%, if required contains Cr: 0.10-0.50%, and is limited to P: not more than 0.02% and S: not more than 0.01%, the remainder being Fe and unavoidable impurities, and has tensile strength and reduction of area determined by the following equations (1) and (2),TS.ltoreq.85.times.(C)+60 (1)RA.gtoreq.-0.875.times.(TS)+158 (2)whereC: carbon content (wt %),TS: tensile strength (kgf/mm.sup.2), andRA: reduction of area (%).