| 摘要 |
PROBLEM TO BE SOLVED: To provide a flux-cored wire for the multiple electrode gas shield arc welding which has excellent welding workability, excellent bead shape and appearance, and excellent primer resistance even at the high-speed welding with the welding speed of≥150 cm/minute, and requires very few repair welding even when any disturbance occurs. SOLUTION: The ratio Sf(%) of the sectional area of a skin to the total sectional area in the wire section ((sectional area of a mild steel-made skin part)/(total sectional area of wire) x 100%) is 30-70%. The Vickers hardness H(Hv) of the skin satisfies the inequality H≤425-3×Sf. The composition consists of, by mass, 3.5-7.5% oxides except alkali metal oxides, 0.01-0.40% alkali metal compound, 0.4-1.2% Si, 1.5-4.0% Mn, and 0.2-0.6% Al. The alkali metal compound is one or two or more kinds selected from the group consisting of K<SB>2</SB>O, Na<SB>2</SB>O and Li<SB>2</SB>O. COPYRIGHT: (C)2006,JPO&NCIPI
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