Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Takuya Asano

Kazuto Yamamoto

Fuminori Watanabe

Tsuyoshi Saito

Hideki Hamatani

Takaaki Fukushi

Takao Miura

Toshihiko Torigoe

Yoshihiko Hirohashi

Nobuo Mizuhashi

Keinosuke Iguchi

Masakazu Ozaki

Shingo Toji

Ryota Horibe

Eri Atsuyama

Hironori Otaka

Kazue Nakano

Kimiharu Tanaka

Kazumoto Tsukakoshi

Noriyuki Sato

Dongliang Li

Takashi Motoyoshi

The present invention provides electric-resistance welded steel pipe optimal for applications such as production of shale gas which is comprised of steel having a chemical composition which contains, by mass %, respectively, C: 0.08 to 0.18%, Si: 0.01% to 0.50%, Mn: 1.30 to 2.1%, Al: 0.001 to 0.10%, Nb: 0.005 to 0.08%, and Ti: 0.005 to 0.03%, is limited to N 0.008% or less, P: 0.020% or less, and S: 0.010% or less, and has a balance of Fe and unavoidable impurities, wherein a structure at a center part of thickness is 40% to 70% by area of ferrite phase having a circle-equivalent diameter of 1.0 &#x3bc;m to 10.0 &#x3bc;m and a balance of a low temperature transformation phase comprising a bainite phase, and Ceq satisfies 0.32&#x2264;Ceq&#x2264;0.60.

Electric-resistance welded steel pipe

Growing community of inventors

Tokyo, Japan

Takuya Asano