| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a steel for electronic-beam welding with which a basic material and a heat-affective zone are suitable to construct the foundation part of a steel tower for wind-force electric generator near the sea, and a toughness for breakage in fused metal zone is suitably balanced; and an electronic-beam welding joint for forming this steel. <P>SOLUTION: The steel for electronic-beam welding, has the prescribed component composition and satisfies 0.42-0.65 electronic-beam welding hardening index CeEBW defined with the following formula (1), and further, a CTOD value δ<SB POS="POST">WM</SB>in the fused metal part, a CTOD value δ<SB POS="POST">HAZ</SB>the heat-affective zone and a CTOD value δ<SB POS="POST">BM</SB>in the basic metal in the electronic-beam welding joint formed by inserting an insert metal into the welding part, are satisfied with the following formulas (2) and (3). Wherein, CeEBW=C+1/4Mn+1/15Cu+1/15Ni+1/5Cr+1/5Mo+1/5V (1), 0.8≤δ<SB POS="POST">BM</SB>/δ<SB POS="POST">WN</SB>≤1.25 (2) and 0.15≤δ<SB POS="POST">HAZ</SB>/δ<SB POS="POST">WM</SB>≤1.1 (3). <P>COPYRIGHT: (C)2012,JPO&INPIT |
