JPS62187514A - Hot rolling method for metal - Google Patents

Abstract

PURPOSE:To keep the required characteristics and quality and to improve the yield of products by detecting a load current value of a driving motor, estimating a temp. of a rolled stock, and controlling a supply amount of a rolling oil based on the above temp. CONSTITUTION:A load current value of driving motors 71...710 of respective rolling stands #1-#10 is detected by current detectors 191...1910. The detected current values are fed back to flow controllers 181...1810 of respective rolling stands so as to control the flow rate of a rolling oil at respective rolling stands #1-#10 and to limit a load current value of respective driving motors 71...710 in the prescribed current range. Since a temp. of the rolled stock 2 during rolling has a prescribed relation to a rolling torque, a supply amount of the rolling oil is regulated to control temps. of the rolled stock 2 and of rolling rolls 81...810, so that the rolling torque and then the load current value of the driving motors 71...710 are varied. The temp. of the rolled stock 2 during rolling at each stage is individually controlled by limiting the above load current values in the temp. range set at each stage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an improvement in a method for hot rolling metal.

[Prior Art] Conventionally, in the case of non-ferrous metals, especially metals such as aluminum that are easy to form into various alloys, if the RI composition is constant, the performance of the product is controlled by the plastic working history. For example, when manufacturing aluminum rough drawn wire using a continuous casting and rolling method, various alloy wires are manufactured in one process. The main use of aluminum wire is for electric wires, but in addition to the regular pure aluminum wire with increased electrical conductivity, there are various aluminum alloy wires with increased heat resistance and tensile strength. Furthermore, there are various needs for alloy wires used for general purposes.

In the continuous casting and rolling process, it is difficult and uneconomical to change the rolling process, especially the rolling pass schedule, depending on the type of material due to equipment constraints.

For this reason, various alloys are cast into ingots with the same cross-sectional area, rolled with the same rolling pass schedule, and finished into products with the same shape. As a result, material temperature control during the rolling process has become extremely important from the standpoint of product performance and quality control.

FIG. 4 shows a general manufacturing process for conventional aluminum rough drawing wire. Belt and wheel type continuous casting machine 1
The rolled material 2, which is an ingot cast in
It enters a rolling mill 3 at a temperature of 0° C., is continuously rolled, is finished into a rough wire 4 of a predetermined diameter, and is wound up by a winding machine 5.

During rolling, rolling oil is applied to each rolling stand of the rolling mill 3 for the purpose of cooling and lubricating the material to be rolled 2 and the rolling rolls of the rolling mill 3.

FIG. 5 shows a cross section at a rolling bath where the rolled material 2, which is an ingot, is rolled by the rolling mill 3 and finished into a rough wire 4. As shown in FIG. For example, a material to be rolled 2 having a cross section of 2,000#2 is rolled into a rough wire 4 of φ9.5# using an oval round hole with <10 stages as shown in the figure.

[Problems to be solved by the invention] In the conventional rolling method, since the temperature of the rolled material 2 is high, it is necessary to apply a relatively large amount of rolling oil during rolling. The temperature of material 2 cannot be measured with a valve contact type thermometer.

At best, it is possible to measure the temperature of the rolled material 2 and the rough line 4 with infrared thermometers at the entrance and exit of the rolling mill 13,
The task was to control the total amount of rolling oil. For this reason, even if the temperature of the material before and after rolling can be controlled, the temperature of the rolled material 2 during rolling cannot be controlled, and as a result, the performance of the rough drawing line 4 deteriorates.

There was a problem with inconsistent quality (tensile strength and electrical conductivity). In particular, for products such as alloy wires that have strict user characteristics, there is a problem in that defective products are easily produced because there are no manufacturing control indicators.

An object of the present invention is to provide a method for hot rolling metal that can control the temperature of a rolled material during rolling to obtain rolled products having desired properties and quality.

Means for Solving Problem L] Means of the present invention for achieving the above object will be explained with reference to FIG. 1, which corresponds to an embodiment.

In the present invention, since the rolling deformation resistance of a rolled material depends on the rolling temperature of the material if the rolled material has the same composition, other rolling material conditions (area reduction ratio) are determined.

It was discovered that by keeping the hole shape, rolling speed, etc. constant, there is a constant relationship between the temperature of the rolled material during rolling and the rolling torque (the load current value of the rolling mill motor), and this property was utilized. This is what I did.

That is, the present invention detects the load current value of the rolling drive motors 71 to 7+o of the hot rolling mill 3 while rolling the material 2 to be rolled in the hot rolling mill 3, and supplies the detected value to the hot rolling mill 3. The temperature of the rolled material 2 during rolling is controlled by controlling the supply amount of rolling oil according to the load current values of the rolling drive motors 71 to 710.

[Function] By detecting the load current values of the rolling drive motors 71 to 710 in this way, the temperature of the rolled material 2 can be estimated, and the supply flow rate of rolling oil is controlled accordingly. 2 temperature can be controlled, making it possible to manufacture rolled products with desired properties and quality.

[Example] Hereinafter, the present invention will be explained in detail based on the example shown in FIG. 1, in which the present invention is applied to a method for continuous casting and rolling of aluminum rough drawn wire. The material to be rolled 2, which is an ingot cast by a belt-and-wheel type continuous casting machine, has a trapezoidal cross-sectional area of approximately 2,000 g*2, for example, and is placed between 10 rolling stands #1 to 1 of the rolling mill 3.
#10 is finished into a rough drawing line 4 with a diameter of 9 and 5 cylinders through an oval/round rolling process as shown in Fig. 5. The temperature of the material to be rolled 2 is measured by an infrared thermometer 6A before entering the rolling mill 3. Rolling mill 3 is a horizontal rolling stand #
1. #3. #5. ...and vertical rolling stands #2, #
4. ..., and in each rolling stand #1 to #10, rolling rolls 81 to 8+o are driven by rolling drive motors 71 to 7+o, respectively.

In each rolling stand #1 to #10, rolling oil supply paths 91, 92,...
・Rolling oil is applied through . Each rolling stand #1
~ The rolling oil accumulated at the bottom of #10 is returned to the rolling oil dirty tank 11 by gravity, and this rolling oil is pumped to the pump 1.
2 passes through a heat exchanger 13 and a filter 14,
Solids such as aluminum powder are removed and then stored in the rolling oil clean tank 15. Rolling oil clean tank 15
The rolling oil entering the inside is cooled by a heat exchanger 13 and controlled within a certain temperature range. Also, when the humidity of the rolling oil is low, such as at the start, the heater 16
and then heated to a predetermined temperature. The rolling oil in the clean tank 15 is supplied to each rolling stand # by a pump 17.
1 to #10 via flow path regulators 181 to 181o and rolling oil supply paths 91 to 9+o. At the exit side of the rolling mill 3, the temperature of the rough wire 4 is measured with an infrared thermometer 6B.

When performing rolling in this manner, in this embodiment, the load currents of the rolling drive motors 71 to 710 of each rolling stand #1 to #10 are detected by current detectors 19+, 192, . . . , 19+.
o, and the detected current value is applied to each rolling stand #1 to #10.
By feeding back to the flow rate regulators 181 to 1810 and controlling the flow rate of rolling oil in each rolling stand #1 to #10, the zero charge current value of each rolling drive motor 71 to 7+o is kept within a predetermined range. Make sure it fits. When controlled in this way, the temperature of the rolled material 2 during rolling has a predetermined relationship with the rolling torque (the load current value of the Φ rolling drive motor), so the supply flow rate of rolling oil is controlled and the temperature of the rolled material 2 is controlled.
By controlling the scars of the rolling rolls 81 to 810, the rolling torque changes and the load current value of the rolling drive motors 71 to 7+o changes, so that this load current value falls within the range set for each stage. By doing so, the temperature of the rolled material 2 at each stage during rolling can be individually controlled.

Figure 2 shows aluminum alloys 2218 and 4032, which are the rolled materials.
The figure shows an example of the relationship between the tensile strength σR and the elongation δ (after heating for 10.000 hours at each dry mark) at each temperature. What is shown is well known.

FIG. 3 shows the temperature control range in each rolling stand #1 to #10 for the aluminum alloy wire that is the material to be rolled. From the performance of the rough drawn wire 4 obtained by rolling by the method of this example, it was confirmed that it was rolled in the above temperature range.

In the above embodiment, each rolling stand #1 to #10 is driven by a separate rolling drive motor 71 to 710, but all the rolling stands are driven by one rolling drive motor or several rolling drives. When driven by a drive motor, even if the total current value of one rolling drive motor or each current value of several rolling drive motors is detected and the same control is performed, the same effect will be achieved although the accuracy will be slightly lower. I can give it to you.

Further, although the above embodiments have been described in the case of a continuous rolling mill, it goes without saying that the present invention can also be applied to a single-stage rolling mill.

Furthermore, in the above example, rolling of A was shown, but A
It goes without saying that the present invention can be similarly applied to the rolling of metal materials other than J2, and can also be applied not only to bar-shaped rolling but also to plate-shaped rolling.

[Effects of the Invention] As explained above, in the present invention, the load current value of the rolling drive motor is detected, the temperature of the material to be rolled is estimated, and the supply flow rate of rolling oil is controlled accordingly. The temperature of the rolled material can be controlled, and rolled products with desired properties and quality can be easily produced. Therefore, according to the present invention, the performance of the product can be reliably achieved, the yield of the product can be significantly improved, and the quality of the product can also be stabilized.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram showing an example of an apparatus for carrying out the method of the present invention, Figure 2 is a diagram showing the relationship between temperature, tensile strength and elongation of the material to be rolled, and Figure 3 is a diagram showing the relationship between the temperature and tensile strength and elongation of the rolled material. Figure 4 is a diagram showing the temperature range of the rolled material, Figure 4 is a conceptual diagram showing the general manufacturing process of aluminum rough wire, Figure 5 is a diagram showing each rolling pass of the rolled material in the manufacturing process shown in Figure 4. FIG. 2... Material to be rolled, 3... Rolling machine, #1 to #10...
・Rolling stand, 4... Rough line, 71~7+o...
Rolling drive motor, 81-8+o...rolling roll, 91
~91o...Rolling oil supply path, 181~181o...
Flow rate adjustment @ Figure 1 Figure 2 @ Figure 3 Figure 5 (°C)

Claims (1)

[Claims] While rolling a material to be rolled in a hot rolling mill, the load current value of the rolling drive motor of the hot rolling mill is detected, and the amount of rolling oil supplied to the hot rolling mill is determined by the amount of rolling oil supplied to the rolling drive motor of the hot rolling mill. A method for hot rolling metal, characterized in that the temperature of the material to be rolled is controlled during rolling by controlling according to a load current value.