| abstract |
An object of the present invention is to provide a thin steel sheet for processing which has excellent low-temperature bake hardenability and aging resistance and also has good workability. SOLUTION: In mass%, C: 0.0020 to 0.010%, Si: 1.0% or less, Mn: 0.05 to 1.5%, P: 0.05% or less, S: 0. 02% or less, N: 0.005% or less, Al: 15 × N (%) to 0.10% and Nb: 0.5 × (93/12) × C (%) to (93/12) × [ C (%)-0.001], the balance being Fe and unavoidable impurities, the average crystal grain size d of the steel sheet being 2 to 12 μm, and the low temperature represented by the following formula (1). The bake hardening index A is set to 10 or less. A = (12/93) × (Nb (%) / C (%)) × d (μm) −10 × C * (%) (1) However, C * (%) = C (%) − (12/93) × Nb (%) [Selection diagram] Fig. 1 |