Hot rolling technique of X80 pipeline steel coil plate

The invention discloses a hot rolling technique of an X80 pipeline steel coil plate, which solves the problem of poor DWTT performance stability of the X80 pipeline steel coil plate with the thickness of at least 20mm produced in the prior art. The hot rolling technique comprises the steps of slab heating, rough rolling, finish rolling, post-rolling cooling and coiling. In the rough rolling, 5-8-pass rough rolling is performed, the rolling temperature of the next-to-last pass is lower than or equal to 980 DEG C, the rolling reduction of the next-to-last pass is greater than or equal to 20%, the rolling temperature of the last pass is lower than or equal to 950 DEG C, and the rolling reduction of the last pass is greater than or equal to 23%; in the finish rolling step, the finish rolling inlet temperature is lower than or equal to 920 DEG C, the finish rolling accumulative rolling reduction is greater than or equal to 62%, and the finish rolling finishing temperature is Ar3+0-30 DEG C (Ar3 is phase-change temperature); and in the post-rolling cooling step, ultra-fast cooling is performed in the ultra-fast cooling system, the ultra-fast cooling finishing temperature is 480-560 DEG C, the average cooling rate is greater than or equal to 40 DEG C/second, and the coiling temperature is 200-400 DEG C. The technique effectively enhances the DWTT fracture toughness on the premise of ensuring the strength of the steel coil.