| 摘要 |
PROBLEM TO BE SOLVED: To provide a hot dip galvanized steel sheet which has excellent chemical conversion treatability, press formability and continuous spot weldability, and to provide a production method therefor. SOLUTION: In a plating film, the content of Al is controlled, by mass, to 0.20 to 0.70%, Fe to≤1.0%, Pb to≤0.005%, and Mg to 0.01 to 0.1%. Further, the arithmetic average roughness Ra of the plating surface is controlled to 0.7 to 1.5μm, and the number of peaks per length of 25.4 mm in the average line direction of a roughness curve: PPI (peaks per inch) is controlled to≥150. The steel sheet is produced by dipping a steel sheet into a hot dip galvanizing bath comprising, by mass, 0.1 to 0.4% Al,≤0.005% Pb and 0.01 to 0.1% Mg for a dipping time of 1.0 to 5.0 s, and thereafter taking up the steel sheet. Temper rolling after the plating can be performed by using a roll having a surface roughness that the arithmetic average roughness: Ra is≥0.7μm, and the number of peaks per length of 25.4 mm in the average line direction of a roughness curve: (PPI) is≥150. COPYRIGHT: (C)2004,JPO&NCIPI
|
