| 摘要 |
A martensitic steel for a line pipe having excellent corrosion resistance and weldability is disclosed. The martensitic steel contains about: 0.02 wt % or less of C, 0.50 wt % or less of Si, 0.2 to 3.0 wt % of Mn, 10 to 14 wt % of Cr, 0.2 to 7.0 wt % of Ni, 0.2 to 5.0 wt % of Mo, 0.1 wt % or less of Al, 0.07 wt % or less of N, and the balance being Fe and incidental impurities; and these elements satisfy substantially the following equations: (Cr %)+(Mo %)+0.1(N %)-3(C %)>/=12.2, (Cr %)+3.5(Mo %)+10(N %)+0.2(Ni %)-20(C %)>/=14.5, and 150(C %)+100(N %)-(Ni %)-(Mn %)</=4. The martensitic steel may further contain at least one element selected from the group consisting of about 2.0 wt % or less of Cu, about 0.15 wt % or less of Ti, about 0.15 wt % or less of Zr, about 0.15 wt % or less of Ta and about 0.006 wt % or less of Ca, and these elements satisfy substantially the following equations: (Cr %)+(Mo %)+0.1(N %)+3(Cu %)-3(C %)>/=12.2, (Cr %)+3.5(Mo %)+10(N %)+0.2(Ni %)-20(C %)>/=14.5, 150(C %)+100(N %)-(Ni %)-(Mn %)</=4.
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| 申请人 |
KAWASAKI STEEL CORPORATION |
发明人 |
KIMURA, MITSUO;MIYATA, YUKIO;KOSEKI, TOMOYA;TOYOOKA, TAKAAKI;MURASE, FUMIO |
