| 摘要 |
<p>Provided is a hot-dip aluminum-coated carbon steel sheet for fuel tanks, which has a good welding gastightness and anticorrosion after forming. The hot-dip aluminum-coated carbon steel sheet comprises a carbon steel sheet, which contains C (0.003 % or less), Si (0.03 % or less), Mn (0.3 % or less), P (0.02 % or less), N (0.006 % or less), Ti (0.1 % or less), Nb plus Ti, which amount to at least an atomic equivalent of (C + N) and at most 0.2 % of (C + N), and B (1 to 30 ppm), and the remainder of Fe and an unavoidable impurities, and a coated layer, which contains Si (2 to 13 %) and the remainder of Al and an unavoidable impurities, and the steel sheet has a total elongation of at least 45 % after coating. Alternatively, the steel sheet may have a chromate film of 5 to 100 mg/m2 on surfaces thereof and may have a resin coat on an uppermost surface thereof. Accordingly, the aluminum-coated carbon steel sheet has a good elongation after aluminum-coating, so that it is considerably excellent in anticorrosion after forming as compared with a conventional one. Therefore, the steel sheet is optimum for automobile fuel tanks, due to an excellent welding gastightness in addition.</p> |
