JPS5942571B2 - hot rolling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot rolling apparatus that is provided with an induction heating coil for heating skid marks in the middle of a hot rolling line.

A method using an induction heating device has been proposed in order to locally heat and remove areas where the temperature is insufficient (hereinafter referred to as skid marks) in hot-rolled metal materials such as relatively thick slabs9). Ru.

As the slab heated in the heating furnace slides on the cooled skid rail, the slab leaving the heating furnace has skid marks 2 on the underside of the slab 1, as shown in Figure 1. do.

The temperature of the skid mark 2 has decreased by about 100° C., and its width is about 30 m71 L, extending over the entire width of the slab 1.

Therefore, in order to heat only that part, local heating induction heating as shown in FIG. 2 is optimal.

If the number of turns of the coil 4 wound around the iron core 3 is N, and the coil current flowing through the coil 4 from the power source 5 is 1°, then the magnetomotive force ■
.

A magnetic path passing through the iron core 3, the gap between the iron core 3 and the slab 1, and a part of the slab 1 is formed by XN, and a part of the slab 1 corresponding to the lower part of the coil 4 is heated by induction.

Note that the iron core 3 and the coil 4 constitute an induction heating device 6.

Now, as shown in FIG.
Place the required number in between.

The skid mark 2 naturally exists only on the conveyance roller 7 side.

As shown in FIG. 4, a slab conveyance speed detector 8 and a thermometer 9 for detecting skid marks 2 are arranged upstream of each heating stage, and their signals are connected to a computing unit 10.

Naturally, the position of each heating stage and the arrangement of the thermometer 9 are input into the computing unit 10 as information for calculation.

Now, when the slab 1 is being conveyed, its conveying speed is taken into the computing unit 10 by the speed detector 8, and the timing of applying power to each induction heating device 6 is computed.

Next, the skid mark 2 of the slab 1 passes through the thermometer 9, which detects the temperature pattern of the skid mark 2 and sends a signal to the calculator 10.

The arithmetic unit 10 applies electric power to the signal so as to eliminate the temperature pattern of the skid mark 2.

Therefore, in order to faithfully eliminate the temperature pattern, the width of the heat generation of the induction heating device 6 should be as small as possible; however, practically, a width of about 1/10 of the skid mark is sufficient.

The timing of applying the electric power must be controlled to a position where the skid mark 2 just passes through the induction heating device 6.

Further, when there are a plurality of heating stages as shown in FIG. 4, the power applied to each stage can be a value obtained by dividing the final temperature increase amount among the plurality of stages.

In addition, in FIG. 4, 11 is a power factor improvement capacitor,
12 is a transformer, and 13 is the conveyance direction of the slab 1.

According to this invention, the conveyance speed of the slab and the temperature of the skid mark are detected, and the electric power that the induction heating device should output is calculated by a calculator, and the skid mark is heated to a predetermined temperature by the induction heating device while conveying the slab. By heating to
Skid marks can be removed while conveying the slab, regardless of the location, temperature variations, distribution, and shape of localized insufficient temperature rise areas that occur on the surface of the slab.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the state of the slab that has occurred in the slab;
FIG. 2 is a perspective view showing the relationship between an induction heating device and a skid mark according to an embodiment of the present invention, FIG. 3 is a front view showing an embodiment of the present invention, and FIG. 4 is the circuit configuration of FIG. 3. FIG. In the figure, 1 is a slab, 2 is a skid mark, 6 is an induction heating device, 7 is a conveyance roller, 8 is a speed detector, 9 is a temperature detector, and 10 is a computing unit. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] 1. Heating the slab on the skid rail in a heating furnace, and heating the skid mark in the insufficient temperature rise area caused by contact with the skid rail to a predetermined temperature with an induction heating device,
For items that are transported by transport rollers and processed by a rolling mill,
Based on the transport speed of the slab detected by a speed detector and the temperature of the skid mark detected by a temperature detector, a computing unit calculates the necessary power to be output by the induction heating device, and transports the slab. 1. A hot rolling device characterized in that it is configured to perform heating while heating. 2. The hot heating device according to claim 1, wherein the induction heating device has a heating width smaller than the skid mark width, and outputs electric power according to the shape of the skid mark by calculating with a computing unit. rolling equipment. 3. The hot rolling apparatus according to claim 1 or 2, wherein a plurality of induction heating apparatuses are provided.