| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel sheet for extra-thin two-piece can, having <=0.20 mm sheet thickness and suitably used for lightweight beverage can and also having T2.5-3 degree of refining and excellent deep drawability multistage necking workability and flange workability, and also to provide its production method. SOLUTION: A low carbon aluminum killed steel stock, having a composition containing <=0.06% C and <=0.0060% N, is heated and hot rolled into a sheet bar, and the sheet bar is hot rolled at >=(Ar3 transformation point + 10 deg.C) FDT and formed into a hot rolled plate while regulating CT to 600-750 deg.C. The hot rolled plate is cold rolled, and the resultant steel sheet is annealed continuously at a temperature not lower than the Ac1 transformation point, cooled rapidly, and subjected to overaging treatment, followed by temper rolling. By this method, the steel sheet having the following characteristics can be obtained: yield stress, <=370 MPa; r-value, 1.0-1.5;Δr-value as the in-plane anisotropy of r-value, 0±0.2; degree of refining, T2-T3; yield stress after 10% working strain applying baking hardening, >=370 MPa; and yield stress after 35% working strain applying baking hardening, <=620 MPa.
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