Technique of controlling and cooling hot-rolled seamless tube online

The invention provides a method for the on line controlled cooling process of a hot rolling seamless steel pipe, the method is realized by a controlled cooling system, and the method comprises the steps that a blower fan and a water pump are started up; the controlled cooling device starts working; the rolled temperature of the seamless steel pipe which is rolled by a three-roller slight tension sizing mill is between 950 DEG C and 980 DEG C, when the tail of the seamless steel pipe is not completely rolled out from the end of the mill housing of the sizing mill, the rotation of the seamless steel pipe can not happen; when the tail of the seamless steel pipe completely breaks away from the end of the mill housing, and is detected by a thermometal detector, meanwhile a changeable angle roller way declines on the horizontal plane according to a set angle, to lead the seamless steel pipe to go forward in spiral way along the rolling direction by the own axis till the whole seamless steel pipe passes through completely; the cooling speed of the process requirement can be achieved finally; subsequently the seamless steel pipe enters into a chain-type cooling bed to implement the air cooling to the room temperature. The invention has the advantages that the controlled cooling process controls the cooling speed of the hot rolling seamless steel pipe after the rolling through the air-mist cooling, to meet the purpose of improving the metallographic structure and the comprehensive mechanical property of the seamless steel pipe.