Jfe Steel Corporation

Atsushi Yonemoto

Takatoshi Okabe

Shunsuke Toyoda

Sota Goto

Tomohiro Inoue

Shigeto Sakashita

Yutaka Matsui

Motoharu Egi

An ultrasonic flaw detection apparatus includes: a seam detection unit that captures a thermal image of a welded seam portion of an electric resistance welded pipe; an ultrasonic flaw detection sensor head that includes an ultrasonic probe that performs ultrasonic flaw detection on the welded seam portion; a seam position calculation unit that calculates a seam position and a bead cutting position of the electric resistance welded pipe; a bead cutting band detection unit that detects a bead cutting band of the electric resistance welded pipe; a bead cutting position calculation unit that calculates a bead cutting position of the electric resistance welded pipe; a tracking movement amount calculation unit that calculates a tracking movement amount of the ultrasonic flaw detection sensor head; and a sensor head driving unit that moves the ultrasonic flaw detection sensor head to track the welded seam portion according to the tracking movement amount.

Ultrasonic flaw detection apparatus and ultrasonic flaw detection method

Electric resistance welded steel pipes or steel tubes with a tensile property TS of not less than 434 MPa which have electric resistance welded parts exhibiting both excellent HIC resistance and excellent low-temperature toughness, and methods for manufacturing such steel pipes or steel tubes.

Electric resistance welded steel pipe or steel tube having excellent HIC resistance and low-temperature toughness in electric resistance welded part, and method for manufacturing the same

A high-strength thick-walled electric resistance welded steel pipe has excellent low-temperature toughness and excellent HIC resistance and a yield strength of 400 MPa or more. The steel has a chemical composition consisting of C: 0.025% to 0.084%, Si: 0.10% to 0.30%, Mn: 0.70% to 1.80%, controlled amounts of P, S, Al, N, and O, Nb: 0.001% to 0.065%, V: 0.001% to 0.065%, Ti: 0.001% to 0.033%, and Ca: 0.0001% to 0.0035% on a mass percent basis and the remainder being Fe and incidental impurities, and satisfies Pcm of 0.20 or less.

High-strength thick-walled electric resistance welded steel pipe having excellent low-temperature toughness and method of manufacturing the same

Growing community of inventors

Tokyo, Japan

Atsushi Yonemoto