| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a thin steel sheet having a Young's modulus of 230 GPa or more.SOLUTION: A steel raw material containing, by mass%, C:0.005 to 0.04%, Si:above 0.5% and 1.5% or less, Mn:1.0 to 3.0%, Al:0.1% or less, N:0.01% or less, and one or two kinds selected from Ti:0.02 to 0.20% and Nb:0.02 to 0.20%, and having an amount of C not fixed as carbide, C* of 0.012 to 0.03, and an atom ratio of Nb to C of 0.5 or less is supplied to hot rolling at a finish-rolling finishing temperature of 850 to 950°C and winding at 650°C or lower and acid cleaning, then cold rolling-annealing twice repeatedly. |
