| 摘要 |
PROBLEM TO BE SOLVED: To provide a stock for an electric resistance welded tube which has a smooth weld zone surface after the cutting away of a weld bead, and is worked into a product shape having no occurrence of cracks by tube shrinking, tube extending or the like. SOLUTION: In the stock, a Ti-added extra low carbon steel sheet to which, by mass, 0.0003 to 0.0050% B is added is used as a base, and a hot dip galvanizing layer, an alloyed hot dip galvanizing layer, a hot dip zinc-aluminum alloy plating layer or a hot dip zinc-aluminum-magnesium alloy plating layer is provided. In the Ti-added extra low carbon steel sheet, the content of C is 0.001 to 0.025%, the content of N is≤0.01%, and the content of Ti is controlled to the range of [(48/12×C+48/32×S+48/14N)+0.01] to 0.10%, by mass. The stock is produced through a hot rolling stage, a cold rolling stage, reduction heating and a hot dip plating stage, and, in the reduction heating prior to the hot dip plating, heating temperature is set to the range of 800 to 900°C, and cooling velocity is set to the range of 10 to 50°C/s. COPYRIGHT: (C)2006,JPO&NCIPI
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