The invention provides a hot rolling process capable of improving high-grade thick pipeline steel
fracture toughness, sequentially comprising a plate blank reheating section process, a hot rolling section process, a plate reeling section process and a cooling section process, wherein the concrete
processing parameters of each process are as follows: in the plate blank reheating section process, the plate blank
heating temperature is equal to T
solid solution plus 30-80 DEG C, the relation between in-furnace time and blank thickness is that the total in-furnace time is equal to 0.5t plus 30-50min, and the
temperature difference of the upper surface and the lower surface after the plate blank is reheated is less than or equal to 30 DEG C; and in the hot rolling section process, the single track down rate in rough rolling is more than or equal to 15%, the accumulated down rate in fine rolling is more than or equal to 70%, and the finished rolling temperature is equal to Ar3 plus 0-60 DEG C, wherein Ar3 is a phase transformation point temperature. By utilizing the hot rolling process provided by the invention, the problem that DWTT (
drop weight tear test) control is difficult to carry out on X70 and X80 steel more than 15mm can be effectively solved. The hot rolling process provided by the invention is practical and feasible and produces less loss on a rolling
machine, a reeling
machine and the like, and the qualifying rate of the DWTT properties of a product can reach up to more than 99%.