Nippon Steel Sumitomo Metal Corporation

Nippon Steel Corporation

Nariyasu Muroga

Shingo Yamasaki

Seiki Nishida

Daisuke Hirakami

Toshiyuki Manabe

Wataru Yamada

Makoto Kosaka

Hitoshi Demachi

Yoshitaka Nishikawa

Shouichi Ohashi

Toshiyuki Kajitani

Nobuyuki Komiya

Kenichi Nakamura

Susumu Sahara

Toshiyuki; Kajitani

The present invention provides a wire rod with a composition at least including: C: 0.95-1.30 mass %; Si: 0.1-1.5 mass %; Mn: 0.1-1.0 mass %; Al: 0-0.1 mass %; Ti: 0-0.1 mass %; P: 0-0.02 mass %; S: 0-0.02 mass %; N: 10-50 ppm; O: 10-40 ppm; and a balance including Fe and inevitable impurities, wherein 97% or more of an area in a cross-section perpendicular to the longitudinal direction of the wire rod is occupied by a pearlite, and 0.5% or less of an area in a central area in the cross-section and 0.5% or less of an area in a first surface layer area in the cross-section are occupied by a pro-eutectoid cementite.

Wire rod, steel wire, and manufacturing method thereof

Provided is a wire rod contains, in mass %: C: 0.6 to 1.1%; Si: 0.1 to 0.5%; Mn: 0.2 to 0.6%; S: 0.004 to 0.015%; and, Cr: 0.02 to less than 0.05%; with a balance including Fe and inevitable impurities in which P is limited to 0.02% by mass or lower and Al is limited to 0.003% by mass or lower; the wire rod has a pearlite in a surface thereof; and, the wire rod has, in a peripheral portion in a cross section thereof, a {110} crystal plane of ferrite in the pearlite, an accumulation degree of the crystal plane being 1.2 or more.

High-carbon steel wire rod exhibiting excellent workability

The present invention provides a high strength, high toughness steel wire rod useful for a PC steel wire, galvanized steel strands, spring use steel wire, cables for suspension bridges, etc. By hot rolling, then directly patenting or reaustenitizing, then patenting a high carbon steel wire rod of a specific chemical composition of the steel and chemical composition, size, and numerical density of inclusions, piano wire rod or high carbon steel wire rod having a structure of mainly pearlite, having an average value of the proeutectoid cementite area ratio of 5% or less in a center region of less than 20% of the wire rod diameter from the center of the wire rod, having a micromartensite size of the C section of 100 &#x3bc;m or less, having a tensile strength of the 170 kgf/mmclass or more, and having a drawing ratio at break of 30% or more is obtained.

High strength, high toughness, high carbon steel wire rod and method of production of same

Growing community of inventors

Tokyo, Japan

Nariyasu Muroga