STEEL MEMBER HAVING EXCELLENT TOUGHNESS IN WELD HEAT AFFECTED ZONE, AND METHOD FOR PRODUCING THE SAME

Title:

STEEL MEMBER HAVING EXCELLENT TOUGHNESS IN WELD HEAT AFFECTED ZONE, AND METHOD FOR PRODUCING THE SAME

Document Type and Number:

Japanese Patent JP2009197267

Kind Code:

A

Abstract:

To provide a steel member having excellent HAZ toughness even in the case high heat input welding is performed, and to provide a method for producing the same.

The steel member has a composition particularly comprising Zr, REM and/or Ca. Also, (a) the steel member includes the oxides of Zr, REM and/or Ca, (b), when the composition of all the oxides included in the steel member is measured and is expressed in terms of independent oxides, ZrO2: 5 to 50%, the oxide of REM: 10 to 50% and/or CaO: 5 to 50% are satisfied, and further, (c), among all the oxides included in the steel member, the number of the oxides with an equivalent circular diameter of 0.1 to 2.0 m is 120 pieces per mm2and the number of the oxides with an equivalent circular diameter of 5.0 m is 5 pieces per mm2.

Inventors:

DEURA TETSUSHI
SUGIMURA TOMOKO
OKAZAKI YOSHIOMI
NAKO HIDENORI
OTA HIROMI

Application Number:

JP2008039335A

Publication Date:

September 03, 2009

Filing Date:

February 20, 2008

Export Citation:

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