Manufacturing process of automobile low-alloy high-strength steel cold-rolled sheet with high product of strength and elongation

The invention relates to a manufacturing process of an automobile low-alloy high-strength steel cold-rolled sheet with high product of strength and elongation, and belongs to the technical field of metallurgy. The technical scheme of the invention is as follows: the manufacturing process comprises a smelting process, a hot rolling process and a cold rolling process, wherein in the cold rolling process, the annealing temperature control is as follows: the soaking temperature is 840-860 DEG C, the slow cooling temperature is 670-700 DEG C, the rapid cooling temperature is 410-430 DEG C, and the aging finish temperature is 350-370 DEG C; and according to strip steel of different thickness specifications, different annealing tape speed target values are planed: the tape speed of the strip steel of 0.8mm specification is 205m/min, the tape speed of the strip steel of 1.0mm specification is 165m/min, the tape speed of the strip steel of 1.2mm specification is 137m/min, the tape speed of the strip steel of 1.5mm specification is 110m/min, the tape speed of the strip steel of 1.8mm specification is 92m/min, the tape speed of the strip steel of 2.0mm specification is 82m/min, and the tape speed of the strip steel of 2.5mm specification is 66m/min. The manufacturing process of the automobile low-alloy high-strength steel cold-rolled sheet with the high product of strength and elongation disclosed by the invention has the beneficial effects that the low-alloy high-strength steel cold-rolled sheet with high product of strength and elongation is produced by modifying the chemical elements and optimizing the hot rolling and cold rolling processes so that the product of strength and elongation of the low-alloy high-strength steel cold-rolled sheet reach 15GPa%, and simultaneously the quality is stably controlled.