Seamless steel pipe is an important type of steel pipe in production and life, and it is an important steel that is strong and durable. Seamless steel pipe in use is also encountered in the case of bending deformation, encounter seamless steel pipe bending and deformation, as long as it can be corrected, then the seamless steel pipe can continue to use, otherwise the seamless steel pipe will have the impact of the use. It is also possible to control the bending of seamless steel tubes, which should be controlled from the following aspects.

Control the curvature of seamless steel pipe quenching can be carried out from the following aspects.

(1) the use of external spraying first after the internal spraying step-by-step cooling process. As the internal spraying of seamless steel pipe water is flowing from one end of the seamless steel pipe to the other end, the seamless steel pipe at both ends of the cooling rate is different, which leads to the bending of the seamless steel pipe. Therefore, we can use the outer spray water cooling first, so that the surface layer of seamless steel pipe first tissue transformation, and then use the inner spray water cooling method to avoid the bending distortion of seamless steel pipe, the inner spray water than the outer nozzle delay time can be used 2 to 10s.

(2) Reduce the length of the overhanging end of the seamless steel pipe on the rotating wheel. Through reasonable rotating wheel layout and seamless steel pipe length control, the overhang of seamless steel pipe end is controlled to ≤ 600 mm, which can effectively reduce the centrifugal force during quenching and reduce the curvature of seamless steel pipe end.

(3) Reasonable control of rotating wheel speed.

(4) Control the center of the water quenching rotary wheel. Rotating wheel center deviation has a large impact on the curvature of seamless steel pipe quenching. After research, the center of the rotating wheel should be controlled at 0 ~ 5 mm.

(5) control the amount and uniformity of water spraying inside and outside. Oil well pipe quenching and cooling using the outer surface laminar flow cooling plus axial injection method, the size and uniformity of the outer spray water, the size of the inner spray water and internal nozzle alignment is also an important factor affecting the bending of seamless steel pipe quenching.