| 摘要 |
PROBLEM TO BE SOLVED: To improve plating properties without causing bare spots even when a high tensile steel sheet having high contents of solid solution strengthening elements such as Si and Mn is used as a base steel sheet. SOLUTION: The base steel sheet consists of a high tensile steel sheet 1 comprising, by mass, 0.001 to 0.20% C, 0.10 to 2.00% Si, 1.00 to 3.00% Mn, 0.01 to 0.50% of one or more kinds of metals selected from Nb and Ti, 0.01 to 1.00% Mo, and the balance Fe with inevitable impurities. Further, an oxidizing layer 3 comprising intergranular oxide or transgranular oxide is formed on the surface layer part of the high tensile steel sheet 1 to form into the boundary with galvanizing 2, and a region where Nb-Mo based or Ti-Mo based precipitates 3a with a diameter of≤20 nm are dispersed by one piece/μm<SP>3</SP>or above, preferably 10 pieces/μm<SP>3</SP>or above is allowed to exist. COPYRIGHT: (C)2008,JPO&INPIT
|
