JPH04262806A - Method for upset welding for rolled stocks - Google Patents

Abstract

PURPOSE:To securely weld rolled stocks in a short time by forming partial contact parts on both end parts of the widthwise direction in the rear end part of an advanced rolled stock and in the front part of a succeeding rolled stock, setting power feeding clamps and executing the resistance heating to the contact surfaces of both end parts, and pressing and welding the relevant contact surfaces by pressing rolls. CONSTITUTION:A power feeding clamp 5 having an L sectional area is provided on a track 6, one power feeding clamp 5 is fixed, the other power feeding clamp 5 can be moved so that it is approached and separated along the direction of the line on the rail 14 of a track 6. Two power feeding clamps are continued by an upset pressure type cylinder 13. The power feeding clamp 5 presses and fixes rolled stocks through a hydraulic cylinder 12 for the clamp and is energized from a current transformer 7. The advanced stock and the succeeding stock are brought by the upset cylinder into contact with each other and a large current from the transformer is supplied to both their ends. In this way, when the contact surfaces are pressurized by the upset cylinder while the stocks are moved by the track, the rolled stocks are welded in a short time and securely.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining rough rolled materials in a continuous hot rolling line in which rough rolled materials are joined and continuously subjected to finish rolling.

0002

BACKGROUND OF THE INVENTION When hot rolling steel materials, usually steel plates of a certain length are intermittently supplied one by one to a rolling mill and rolled. In this case, the leading and trailing ends of the steel sheet are not only defective in shape and have to be cut off, resulting in a poor product yield, but also are subject to impact loads each time the steel sheet is caught in the roll or ejected from the roll. , there are many opportunities for roll defects to occur, and there are problems such as roll replacement costs and loss of rolling stop time due to roll replacement.

[0003] Therefore, a plurality of steel plates were prepared in advance as shown in Fig. 8 (
If the facing surfaces are connected as shown in a) and rolled continuously with the rolling rolls 4, the above problem will not occur and productivity will be greatly improved. As a result, in general, when a relatively thin steel plate (10 mm or less) is subjected to continuous cold rolling or continuous pickling, steel materials 1 and 2 are joined by flash butt welding or the like as shown in Fig. 8(b). However, in the hot rolling process, the plate thickness is as thick as 20 to 50 mm, so the current capacity to be supplied by the current transformer 7 and power supply clamp 5 is insufficient, and it is difficult to join the entire cross-sectional area in a short time. It is difficult.

Therefore, as shown in FIG. 7, the front and rear steel plates 1,
A method has been proposed in which the ends of the two are overlapped and then a nail-like material 3 is driven in, or they are temporarily fixed by welding and then pressed together using a rolling roll 4, but this method requires a special pressing process and is not suitable for uniform running. However, there are various problems in achieving the goal of bonding in a short time, and it has not been put to practical use.

[0005] An object of the present invention is to provide a method for upset joining rolled materials, which enables rolling materials to be joined and rolled reliably in a short time.

[0006]

[Means for Solving the Problems] The present invention achieves the above-mentioned objects in a continuous rolling line in which the trailing end of a preceding rolled material and the leading end of a trailing rolling material are joined and continuously rolled.
On at least one of the facing surfaces of the rear end of the preceding rolled material and the front end of the trailing rolled material, both ends are processed so that only both ends in the sheet width direction are in contact with each other, and the rear end of the preceding rolled material is A power supply clamp device that can move in the rolling line movement direction is attached to the front end of the rolling material and the tip of the trailing rolled material, and the contact surfaces formed at both ends of each opposing surface are resistance heated, and when the rolling temperature is reached, The contact surface is pressure-bonded using a pressure roller or an upset pressure device.

[0007]

[Operation] Both ends of the leading rolled material and the trailing rolled material are clamped by a power supply clamp device, and the contact surfaces are energized and pressurized. Thereafter, when the temperature reaches a point at which pressure can be applied, the contact surfaces are pressed and joined using a pressure roller or an upset pressure device. In addition, for example, with a thick plate of 20 mm to 50 mm, 700 mm to 2000 mm
Even when the contact surfaces at both ends in the plate width direction of a rolled material with a plate width of mm are about three times the plate thickness, it can be joined in a short time of 5 seconds or less. The temperature of the rolled material in this case is 900°C to 1100°C.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to FIGS. 1 to 6. In addition, in the same parts as FIGS. 7 and 8,
The same symbol shall be attached. 1 and 2 mainly show the respective directional surfaces of the preceding rolled material 2 and the succeeding rolled material 1, and represent the shape of the opposing surfaces and the shape of the contact surface 16. Figure 1 (a1) (a2)
In the case of cutting in a straight line, the terminal end of the preceding rolled material (referred to as the leading material) 2 is cut into a concave shape with protrusions at both ends, and the leading end of the trailing rolled material (referred to as the trailing material) 1 is cut into a concave shape with protrusions at both ends. Cut into straight lines and butt them together. FIGS. 1(b1) and 1(b2) show the case of cutting in an arc shape, and this shape can be used even when the rolled material is individually and intermittently rolled. That is, if the shape is arcuate, the impact when biting into the roll is reduced and the life of the roll is extended. FIGS. 2(a1) and 2(a2) show the case where cutting is performed by changing the radius of curvature between the terminal end of the preceding material 2 and the leading end of the succeeding material 1, and the cutting blade structure can be simplified and roughened. Figure 2 (b1
)(b2), one is arcuate and the other is linear. Both can be used to join materials of different widths.

FIGS. 3, 4, and 5 show the configuration for the method of the present invention. In FIG. 3, a rail 11 is attached along the line along which the rolled material runs, and wheels are run on this rail 11. A trolley 6 having 10 is running. In this case, the truck 6 travels at the same speed as the preceding material 2.

A power supply clamp 5 having an L-shaped cross section is provided on the trolley 6, one power supply clamp 5 is fixed on the trolley 6, and the other power supply clamp 5 is connected to the one power supply clamp 5 by the power supply clamp 5 having an L-shaped cross section. It is provided so as to be movable along the line direction on the rail 14 so as to approach and move away from each other. These two power supply clamps 5 are connected to each other by an upset pressurizing cylinder 13. The power supply clamp 5 is configured to press and fix the rolled material from both sides in the width direction using a clamping hydraulic cylinder 12. The two power supply clamps 5 are also connected to a power source, and are connected from the current transformer 7 via a bus bar 9 on the secondary side. In this case, one power supply clamp 5 and the other power supply clamp 5 are energized.

In the apparatus shown in FIGS. 3(a) and 3(b), a trailing material 1 on a table roller 8 is pressed against a leading material 2 which is being rolled at a constant speed at an increased speed. The cart 6, which is traveling at a constant speed, is fixed to the leading material 2 and the trailing material 1 by the power supply clamp 5 by the operation of the clamping hydraulic cylinder 12. Next, the upsetting cylinder 13 brings the leading material 12 and the trailing material 1 into contact with each other under a certain pressure. Here, a large current supplied from the current transformer 7 is applied to both ends of the leading material 2 and the trailing material 1 through the bus bar 9 and the power supply clamp 5. Here, for example, the current density is 20~
100A/mm2 Current application time is 5 to 0.1 seconds. After this, the temperature of the contact surface 16 at the end in the width direction of the plate rises due to the contact resistance and volume resistance of the contact surface, and when the temperature reaches a point where pressure welding is possible, the upsetting force of the cylinder 13 is increased and pressure welding is performed, and the preceding material 2 and The joining of trailing material 1 is completed. Next, the power supply clamp is opened, and the traveling trolley returns to its initial position and waits until the next connection.

In FIG. 3, the power supply clamp 5 is shown in FIG. 4(a).
As shown in Fig. 4(b), a cylinder having an L-shaped cross-sectional shape was used, but as shown in Fig. 4(b), the rolled materials 1 and 2 were placed in a separate hydraulic cylinder 12 for clamping. The clamping hydraulic cylinder 17 may be used to press and fix from above. In the latter case shown in FIG. 4(b), there is an advantage that the contact area with both ends in the width direction of the rolled material can be large, and there is no need to consider buckling in the width direction of the sheet. In the figure, 15 indicates a truck driving device.

In resistive heating, as shown in FIG. 5, the leading material 2 and the trailing material 1 are in contact with each other at their contact surfaces and are clamped by the power supply clamp 5, and the leading material 2 is moved and Similarly, while the trolley 6 is moving, a current flows from a power source (not shown) through the current transformer 7 and the busbar 9 to the contact surface between the power supply clamps 5. In this case, since it is necessary to conduct all the current to the contact surfaces, the upsetting pressurizing cylinder 13 and the power supply clamp and the power supply clamp 5 and the trolley 6 are insulated. After the contact surfaces are heated to a temperature that allows pressure welding, the upset cylinder 13 is operated to press the contact surfaces of the preceding material 2 and the succeeding material 1 together.

FIG. 6 shows the possible welding range for joining rolled materials at 900° C., and shows the relationship between the current density on the vertical axis and the current application time on the horizontal axis. Therefore, in order to set the target bonding time to 5 seconds or less, the current density must be 20
It turns out that A/mm2 or more is required.

[0015]

Effects of the Invention As explained above, according to the present invention, a contact surface is formed and the contact surface is energized, and the contact surface is pressed by an upset cylinder while moving on a trolley. can be joined reliably in a short time, and the direct voltage improves efficiency. Only the current transformer needs to be mounted on the running gear, making it smaller and lighter. It can also serve as a simple device compared to other methods. Also,
Since the joining positions are at both ends of the wide rolled material, interference with table rollers is less likely to occur, making it easy to change from continuous hot rolling to badge rolling.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the end shape of a rolled material.

FIG. 2 is a diagram showing the end shape of rolled materials to be joined.

FIG. 3 is a block diagram for an embodiment of the method of the invention.

FIG. 4 is a configuration diagram showing types of power supply clamps.

FIG. 5 is a diagram showing a current energization state.

FIG. 6 is a graph showing an example of joining conditions for rolled materials.

FIG. 7 is an explanatory diagram of a conventional joining method.

FIG. 8 is an explanatory diagram of the joint surfaces necessary for rolling and conventional flash butt welding.

[Explanation of symbols]

1 Trailing material 2 Preceding material 4 Roll roll 5 Power supply clamp 6 Dolly 7 Current transformer 9 Bus bar 11, 14 Rail 12, 17 Clamp hydraulic cylinder 13 Upset pressure cylinder 16 Contact surface

Claims (1)

[Claims] Claim 1: In a continuous rolling line in which the rear end of the preceding rolled material and the leading end of the trailing rolling material are joined together and continuously rolled, the trailing end of the leading rolling material and the leading end of the trailing rolling material are connected. At least one of the surfaces facing the section is processed so that only both ends in the sheet width direction are in contact with each other, and the rear end of the preceding rolled material and the leading end of the trailing rolled material are aligned in the rolling line movement direction. A power feeding clamp device that can be moved is attached, and the contact surfaces formed at both ends of each opposing surface are resistance heated, and when the temperature reaches a temperature that allows rolling, the contact surfaces are applied with a pressure roller or an upset pressure device. It was crimped. An upset joining method for rolled materials characterized by the following.