Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Arata Iso

Seiki Nishida

Shingo Yamasaki

Naoki Matsui

Daisuke Hirakami

Toshiyuki Manabe

Susumu Sahara

A wire rod according to an aspect of the present invention has a predetermined chemical composition, a solute N is 0.0015% or less, a structure in an area from a surface of the wire rod to a depth of &#xbc; of a diameter of the wire rod in a cross section thereof includes 90.0 area % or more of pearlite, and 0 to 10.0 area % in total of bainite and ferrite, a total amount of martensite and cementite in the area from the surface of the wire rod to the depth of &#xbc; of the diameter of the wire rod is limited to 2.0 area % or less, and the calculated maximum size of TiN-type inclusions in a surface layer area of the wire rod is 50 &#x3bc;m or less.

Wire rod

A high strength wire rod in which an area fraction of pro-eutectoid ferrite is 3% or less and an area fraction of pearlite structure is 90% or more, being obtained by subjecting a hard steel wire rod having specified composition to a molten salt patenting treatment directly after hot-rolling or after performing re-austenitization subsequent to hot-rolling.

High strength wire rod excellent in drawability and method of producing same

A wire rod which is mainly composed of pearlite and has an area fraction of 5% or less of a non-pearlite structure composed of pro-eutectoid ferrite, degenerate-pearlite or bainite in a section, or has an area fraction of 10% or less of a non-pearlite structure in a portion from the surface to a depth of 100 &#x3bc;m.

Growing community of inventors

Kitakyushu, Japan

Arata Iso