Production process capable of guaranteeing Z-direction performance percent of pass of medium-thickness steel plate

The invention discloses a production process capable of guaranteeing the Z-direction performance percent of pass of a medium-thickness steel plate. The specification range of the medium-thickness steel plate is 10-80 mm. It is guaranteed that the heating time is 3.5-4.5 h, the temperature of a soaking zone is 1150-1250 DEG C, and the heating time of the soaking zone is 30-45 min. The tapping temperature is 1100-1180 DEG C. Operation is conducted at high temperature, low speed and high pressure, and it is required that the initial rolling temperature is 1080+/-20 DEG C. The rolling speed is 0.5-1.5 m/s. According to the rolling reduction, during the first three passes of the rough rolling period, the effective stress [([delta]tmax/k0)-1] is larger than or equal to 0.15. In the fine rolling period, it is guaranteed that the accumulation deformation rate is larger than or equal to 70% for a steel plate with the thickness being 10-60 mm, and it is guaranteed that the accumulation deformation rate is larger than or equal to 60% for a steel plate with the thickness being 60-80 mm. During accelerating control cooling (ACC) laminar cooling, the cooling speed is controlled to be 5-12 DEG C per second, and the finish cooling temperature is controlled to be 580-700 DEG C. When the steel plate is subjected to stack cooling after being off line, the stack cooling temperature is 250-350 DEG C, and the stacking cooling time is 24-48 h. The produced medium-thickness steel plate is uniform and fine in texture and has no obvious segregation or crack defects, and the Z-direction performance percent of pass can reach 100%.