Abstract: Heat treatment process and distortion control of induction quenching at the end of the rolling mill guide frame were studied, for which the corresponding end forgings were specially made and the inductor heating and cooling tests were carried out. At the same time, the relevant process tests were carried out. The hardness, distortion, cracking and other risks of the special-shaped section of the end of the guide frame were comprehensively evaluated. Based on the process test results of the end, an induction quenching process for the end of the guide frame was developed with the heating frequency of 1.7-4 kHz, the walking speed of 150 mm/min, and the power of 90×(14%-24%) kW. The magnetic displacement was designed for the inductor, and the continuous heating and continuous cooling induction quenching was adopted. The results show that based on end profiled structure designed by copying inductors by the process test, 40° guide end profiled induction quenching heat treatment can be realized. By setting the magnetic displacement area reasonably on the inductor, the sharp angle effect at the end of the noncircular section is effectively avoided, and is conducive to the uniformity of induction heating temperature. The C35E steel end after induction quenching hardness can reach 55-60 HRC. Through reverse distortion operation, the bending distortion of the end of the guide frame with a total length of 2120 mm can be controlled within 1 mm.

Key words: guide frame end, special-shaped section, induction quenching, magnetic displacement, reverse distortion