Seamless steel pipe
is an important type of steel pipe in production and life. It is an important steel that is relatively strong and durable. Seamless steel pipes will also encounter bending deformation during use. When the bending and deformation of seamless steel pipes are encountered, as long as they can be corrected, the seamless steel pipe can continue to be used, otherwise the seamless steel pipe will be There are effects of use. It is also possible to control the curvature of seamless steel pipes, which should be controlled from the following aspects:
Controlling the curvature of seamless steel pipe during quenching can be carried out from the following aspects:
(1) Adopt a step-by-step cooling process of external spraying first and then internal spraying. Since the internal water spray of the seamless steel pipe flows from one end of the seamless steel pipe to the other end, the cooling rate of the seamless steel pipe at both ends is different, which causes the seamless steel pipe to bend. Therefore, the external spray water cooling can be used first, so that the surface layer of the seamless steel pipe will undergo structural transformation first, and then the internal spray water cooling method can be used to avoid the bending distortion of the seamless steel pipe. The internal water spray has a delay time of about 2~ 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 tube length control, the overhang of the seamless steel tube end is controlled to ≤600 mm, which can effectively reduce the centrifugal force during quenching and reduce the curvature of the seamless steel tube end.
(3) Reasonably control the rotation speed of the rotating wheel.
(4) Control the center of the water quenching rotating wheel. The deviation of the center of the rotating wheel has a great influence on the curvature of the seamless steel pipe during quenching. After research, the center range of the rotating wheel should be controlled within 0 ~ 5 mm.
(5) Control the amount and uniformity of spray water inside and outside. When oil well pipe quenching and cooling adopts outer surface laminar cooling and inner axial spray, the size and uniformity of the outer spray water volume, the inner spray water volume and the centering degree of the inner nozzle are also the curvature of the seamless steel pipe during water quenching important influencing factors.