| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that impact characteristics are not always improved simply by reduction of penetrators as hereto reported in electric resistance weld part. SOLUTION: The electric resistance welded steel pipe for line pipe excelling in weld part toughness exhibits an area fraction of microdefects of less than 50 μm maximum length in a projection plane of electric resistance weld part ranging 0.035 (further 0.028 or less) and exhibiting an absorbed energy at -40°C, as measured in Charpy test by a metal material impact testing method, of 100 J or greater (further 250 J or greater). COPYRIGHT: (C)2009,JPO&INPIT
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