Rod-coil after-rolled water blocking and slow cooling device and bar material rolled steel production line

The invention provides a rod-coil after-rolled water blocking and slow cooling device which comprises at least one slow cooling section, wherein the slow cooling section comprises a slow cooling guide pipe, a water blocking box and a high pressure medium tank; the slow cooling guide pipe is provided with a slow cooling inner cavity communicating with external air; the water blocking box covers the slow cooling guide pipe; the water blocking box is provided with a water blocking medium cavity and a medium inlet; the water blocking medium cavity communicates with the slow cooling inner cavity through a plurality of nozzles; the nozzles and the rolling direction of a bar material form an included angle; and the high pressure medium tank is used for filling the water blocking medium cavity with a water blocking medium and is connected with the medium inlet. The rod-coil after-rolled water blocking and slow cooling device provided by the invention can block water when slowly cooling a rolled piece, so that the inf