A method for on-line continuous cooling of hot-rolled seamless steel pipes

Abstract

The invention provides a method for online continuous cooling of hot-rolled seamless steel pipes. The method is implemented through a conveyor roller, a pipe-turning mechanism, a control cooling device and an automated control system; it includes the following steps: (1) The hot-rolled seamless steel pipes are completely After passing through the sizing machine, it is transferred to the inclined roller table through the pipe turning mechanism on the straight roller table, and the running speed of the inclined roller table is adjusted; (2) After the hot-rolled seamless steel pipe enters the control cooling device, the roundness is controlled according to the process needs. The number and opening methods of the circular spray rings are adjusted, and the cooling water pressure and cooling water flow rate in the circular spray rings are adjusted so that the steel pipe can be cooled online at a cooling speed of 5 to 40°C / s; (3) After cooling, the temperature is between 150 and 150 The 750℃ steel pipe completely exits the controlled cooling device, returns to the straight roller table through the pipe turning mechanism on the inclined roller conveyor, and is transferred to the cooling bed for air cooling to room temperature; (4) When the previous steel pipe completely exits the controlled cooling device, the next steel pipe is The steel pipe undergoes the online cooling process of steps (1) to (3).

Description

Technical field [0001] The invention belongs to the technical field of metal material processing and forming, and particularly relates to an online continuous cooling method for hot-rolled seamless steel pipes. Background technique [0002] The main production process of hot-rolled seamless steel pipes is that the billet is heated by the ring furnace and then transported to the piercing machine for piercing. The pierced waste pipe is rolled by the continuous rolling mill, and then sizing by the sizing (reducing) machine, and finally transported to Cold bed. Due to the large deformation resistance during the piercing and continuous rolling process, piercing and continuous rolling are carried out at a higher temperature due to the limitation of equipment and processes, and most of the pipes after sizing are air-cooled, and the cooling rate of air-cooling is extremely low. The lack of effective means to control the cooling path often results in coarse microstructure grains of the p...

AI Technical Summary

Problems solved by technology

This method uses the electric drive mechanism to frequently reverse the roller table (return and reset each steel pipe once it is cooled) to realize the rotation of the steel pipe. The operation is more complicated, and the maximum temperature drop is about 270°C. The cooling capacity is poor, and the tissue control ability is limited. No direct quenching process implemented

[0006] CN101396695A discloses "an on-line accelerated cooling device and method for hot-rolled seamless steel pipes", which uses a horizontal rotation mechanism and electrical component control equipment to adjust the angle of the roller table to change the way the steel pipes advance, without specifying the specific method for controlling the cooling of the steel pipes; The coolers used in the method are symmetrically arranged up, down, left and right by spraying water. In actual operation, it is difficult to fully cover the cooling of the circular section of the rotating steel pipe. There are cooling blind spots in the cooling process of the steel pipe, and precise control cannot be achieved. The temperature and cooling uniformity of the cooled steel pipe

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