How to control the bending degree of S235JRH seamless steel pipe during quenching

(1) Adopt a step-by-step cooling process of external spraying first and then internal spraying. Since the internal water spray of the S235JRH seamless steel pipe flows from one end of the S235JRH seamless steel pipe to the other end, the cooling rate of the S235JRH seamless steel pipe at both ends is different, which causes the S235JRH seamless steel pipe to bend. Therefore, the external spray water cooling can be used first, so that the surface layer of the S235JRH seamless steel pipe will undergo structural transformation first, and then the internal spray water can be used for cooling to avoid bending distortion of the S235JRH seamless steel pipe. The delay time of the internal water spray is longer than that of the external nozzle, which can be 2 to 10s.

(2) Reduce the length of the overhanging end of the S235JRH seamless steel pipe on the rotating wheel. Through reasonable rotating wheel layout and S235JRH seamless steel pipe length control, the overhang of the S235JRH seamless steel pipe end is controlled to ≤600 mm, which can effectively reduce the centrifugal force during quenching and reduce the end curvature of the S235JRH seamless steel pipe.

(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 S235JRH 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.

The above is the main methods of controlling the curvature of the common S235JRH seamless steel pipe. When the S235JRH seamless steel pipe is bent and deformed, it can be corrected, and it can be used after the correction is completed.