The invention relates to a low carbon cold-rolled steel sheet for a LED
lead frame and a production method thereof, and mainly solves the technical problems that the low carbon cold-rolled steel sheet for the LED
lead frame in prior art has nonuniform
hardness,
high surface roughness and bad aging-resistance. The production method comprises the following steps:
smelting according to components, molten iron desulphurization, complex top-bottom blowing converter
smelting,
argon blowing from bottom of a
ladle, protective
casting with
argon blowing in whole course, heating in a slab
heating furnace, rough rolling, finish rolling, reeling for obtaining a hot-rolled steel coil, uncoiling,
pickling, cold rolling, annealing in a vertical type
continuous annealing furnace, flattening, and reeling for obtaining a finished product with a thickness of 0.4-0.5mm; the finishing temperature of the finish rolling is 860-900 DEG C, the reeling temperature of the hot rolling is 620-660 DEG C, the cold rolling reduction is 75-85%, the temperature scope of a soaking zone of the vertical type
continuous annealing furnace for a band steel in hard rolled state after cold rolling is 710-730 DEG C, the soaking time for the band steel in the vertical type
continuous annealing furnace is 105-120 s, and temper elongation is 1.0-1.4%. The low carbon cold-rolled steel sheet is mainly used for the LED
lead frame.