After the round steel is rolled out of the finished pass, it is processed in the width direction in a pass composed of two vertical rollers to obtain high-precision bars and wire rods.
When rolling by the longitudinal rolling method on a rolling mill with horizontal rollers, the round steel is only processed in the height direction in the finished hole, and the two sides in the width direction are made of wide arcs of elliptical rolling pieces; at the same time, when designing the pass, Considering that the adjustment range of the hole pattern can make full use of all deviations in the size of the round steel, the hole width is generally made larger than the hole height.
Therefore, the horizontal width direction of the rolled piece cannot be processed well, resulting in rough surfaces on both sides; and because the hole width is greater than the hole height, the out-of-roundness deviation of the round steel changes greatly and is difficult to control.
Especially for round steel with smaller dimensions, the temperature of the rolled piece fluctuates greatly, and the width of the finished product is more difficult to control, making it easy to produce defective or scrap products.
Therefore, adding a vertical rolling line after the finished hole and processing the width of the rolled piece can more accurately control the ovality of the round steel, greatly reduce the size deviation of the round steel, and make the surfaces on both sides of the horizontal direction smooth.
The rounding machine is a vertical roller mill and is connected to the finished rolling mill for continuous rolling. The linear speed of the rounding machine is generally 3% to 5% greater than that of the finished machine, and it is driven by the finished rolling mill or independently.