Nippon Steel Corporation

Masanobu Yamaguchi

Hajime Nakasugi

Hisashi Gondo

Masatoki Nakayama

Masakuni Wakabayashi

Hiroyuki Homma

Naomichi Mori

Katsuhiko Narihara

A method for producing line pipe of high strength and high toughness by the submerged-arc welding process in which a welding wire containing 0.18-0.55% C. is used, Ti or B or both are added to the welding wire or flux or both, and a steel containing 0.005-0.06% C. is welded by the submerged-arc welding process, whereby both Ti and B are caused to be present in the weld metal.

Method for submerged-arc welding a very low carbon steel

A method for heating steel pipe for induction heating coils, while the pipe is travelling through said coils in the axial direction, which comprises:

Induction heating method of steel pipe

A method for producing a large diameter steel pipe having excellent shape, toughness and tensile strength by subjecting the pipe to descaling and to heat treatment which involves heating the steel pipe locally successively from one end to the other end of the steel pipe in the axial direction and forcedly cooling the pipe, and then expanding the steel pipe after the heat treatment.

Method for producing large diameter steel pipes

Growing community of inventors

Kimitsu, Japan

Masanobu Yamaguchi