Outer hexagonal steel (attributes: outer circle inner hexagonal precision special-shaped steel pipe).
Hexagonal steel production plant.
The forming method of hexagonal steel in the outer circle, the special-shaped rail is a special rail that realizes the connection of rails of different heights of the line.
At present, the method usually adopted for manufacturing the outer circle hexagonal steel is to heat a certain length of one end of the higher rail to a high temperature in the heating furnace as a whole, and then reduce the rail pressure to the height of the lower rail on the large tonnage (more than 15mn) press. Due to the overall heating, the geometry of rail cross-section has changed after compression, in order to correct this change, usually on the rolling forging machine of about 1 meter in diameter and then hobbing to restore the original geometric shape, this traditional manufacturing process needs large press and rolling swaging machine, and the production process is complex, the cost is high, the production environment is harsh and a lot of energy is wasted.
An object of the present invention is to provide a new outer circle inner hexagonal steel forming method, and this method can save equipment investment, save energy, reduce production cost, improve product quality.
The object of the present invention is realized in this way: the method comprises the following steps sequentially:
a.Select a rail with higher rail height at one end, and the rail waist part of a certain length is locally heated to 850-950 degrees;
b.The rail that has been locally heated by above-mentioned rail waist part is provided with die at its heating part, and the rail waist of a certain length is formed into symmetrical curved surface rib shape by vertical pressurization on the press, and the rail bottom forms a slope shape transition;
c.Cut off the excess at the standard length;
d.Drill holes at both ends to standard sizes.
Described local heating method is flame jet method or electric heating method.