Hollow drill steel rolling process

Abstract

The invention relates to a hollow drill steel rolling technique, including the working procedures of medium frequency induction heating, perforating by two roller inclined rolling, reducing diameter by three roller-core inclined rolling, fixing diameter and molding by three-roller vertical rolling, and controlling and cooling, and its character: behind working procedure of the medium frequency induction heating, there is an industrial frequency soaking working procedure and the adopted device is an industrial frequency soaking furnace. It adds industrial frequency soaking working procedure to the steel rolling technique, ensuring the inner gold phase tissue of finished product is uniform; it improves hollow drill steel gold-phase tissue and eliminates the inner-surface thread of the central hole and the roll defect, prolongs the service life of the drill steel.

Description

technical field [0001] The invention belongs to the field of brazing steel, in particular to the rolling process of hollow brazing steel. Background technique [0002] The rolling quality of the brazing steel is one of the important factors affecting the life of the brazing steel, especially the rolling quality of the outer surface and inner hole of the brazing steel has the greatest influence on the fatigue limit. [0003] At present, abroad, represented by the Swedish Sandvik company, adopts the "steel billet drilling with core hot rolling method", referred to as "drilling method". In this method, the refined steel round billet is peeled, drilled through the hole, inserted into the high manganese steel mandrel, and then heated with fuel oil or gas, and rolled into the inner core after 19 to 21 passes on the special short stress line rolling mill. Hexagonal or circular hollow brazing steel with a cut circle diameter of φ19~φ51mm, its production process and technological pr...

AI Technical Summary

Problems solved by technology

[0006] To sum up, the main reason for the short service life of the current brazing steel is the problems in the rolling production process: first, the temperature difference between the inside and outside of the round steel billet heating is large, and second, the shape of the center hole and the quality of the inner surface of the reducing and forming process cannot be guaranteed