The invention relates to a manufacture process of
carbon steel and
carbon steel hot rolling plate, in particular to a manufacture process of
fine grain reinforcement carbon structural steel and hot rolling sheet plate of the steel. The invention mainly solves the technical problem that hot rolling plate of higher strength can not be produced on common completely continuous hot
continuous rolling mill by use of common carbon structural steel at present. The
fine grain reinforcement carbon structural steel adopts the following
chemical composition (weight percent): 0.14 percent to 0.20 percent of C, 0.10 percent to 0.40 percent of Si, 0.65 percent to 0.90 percent of Mn, less than or equal to 0.025 percent of P, less than or equal to 0.015 percent of S and the rest, Fe. The manufacture process of the hot rolling sheet plate is as follows: a
continuous casting slab which meets the requirements of compositions is heated to 1,210 DEG C to 1,250 DEG C; a rough rolling stage comprises five-pass tandem rolling and the end temperature of the rough rolling stage is between 1,050 DEG C and 1,060 DEG C; in addition, the thickness of an intermediate slab ranges from 35 mm to 45 mm. When rough rolling is finished, the intermediate slab is curled through a hot coil box and then is unfolded for finish rolling; a finish rolling stage comprises six-pass tandem rolling with the start rolling temperature
ranging between 920 DEG C and 940 DEG C and the end temperature
ranging between 820 DEG C and 860 DEG C; after finish rolling, the thickness of a steel plate is between 2 mm to 8 mm; in addition, a laminar flow cooling stage adopts forepart intensive cooling with the coiling temperature
ranging from 520 DEG C to 620 DEG C.