High-strength medium plate production process

The invention discloses a production method of a high-intensity and medium-thickness steel plate and the technique process comprises heating-descaling-rolling-straightening-controlled cooling, while the specific technique is that: the temperature is heated to 1150-1200 DEG C; the temperature range of rough rolling is set at 1000-1100 DEG C; the rough rolling is done no less than three passes and the initial draft is no less than 10 percent; large rolling reduction is adopted in a finish rolling stage and the cumulative amount of deformation of the finish rolling is no less than 60 percent and the temperature of the finish rolling is 840-930 DEG C while the temperature of final finish rolling is 800-880 DEG C; the steel plate out from a finishing mill is conveyed to a straightening machine directly with the straightening temperature of 800-880 DEG C and then is controlled cooling with the cooling speed of 6-15 DEG C per second and the final cooling temperature of 400-500 DEG C. Due to adjustment of technique of heating, rolling, straightening and cooling, etc., the medium-thickness steel plate with straightness below 10 IU can account for 95 percent, thereby solving the problem that the straightness of the medium-thickness steel plate fails to meet the standard so as to meet the application demand from users, reducing damages of production equipment in the low-temperature rolling process as well as the problems caused by that the steel plate has not been pre-treated by the straightening machine before the controlled cooling.