JPH0985301A - Continuous rolling method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a method for flash butt welding and deburring of the welded portion so that a billet processing time cycle is established in consideration of the capabilities of the current continuous rolling equipment. SOLUTION: In the case of a standard billet processing time cycle which is determined by a billet weight and a rolling capacity, the welder 3 and the grinder 4 are configured as separate types that can run independently, and the welder is independently operated after welding. After returning to the standby position, the grinding machine backs the billet welded part so that it will pick up and then starts grinding to shorten the time cycle, and when the time cycle is longer than the standard billet processing time cycle, the welding machine and the grinder are Welding and deburring are performed by constructing as an integral type.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous rolling method for a straight billet from a continuous casting machine.

[0002]

2. Description of the Related Art In order to continuously roll a billet sent directly from a continuous casting machine, descaling is carried out mechanically or hydraulically to remove the scale formed on the billet surface, and the billet moving at the rolling speed is run. In this continuous rolling method, flash butt welding is used to continuously connect, burrs generated during flash butt welding are ground and removed during running, and a series of steps of heating with an induction heater is performed, followed by continuous rolling. There is. In order to carry out HDR continuous rolling with the current technology, considering the balance between the ability of the continuous casting machine and the rolling ability, the continuous casting machine usually has 2 to 4 strands and the billet weight is 1 to 4 tons. . On the other hand, rolling capacity has been 60-100T in recent years.
/ Hr occupies most of the range, and considering this situation, it is desirable that the above billet size can also support this rolling capacity even in HDR continuous rolling, but the rolling capacity relative to the billet weight is When it is high, the time cycle of billet welding-deburring treatment time must be short.

[0003]

The relationship among the billet weight x (ton / billet), the rolling capacity y (T / Hr), and the billet processing time cycle Ts during continuous rolling is expressed by the following equation. y = (3600 / Ts) × x (1) The processing time for one billet at a factory with a rolling capacity of 60 (T / Hr) for 1 (ton) billet is Ts = 3600 from equation (1).
(s) ÷ 60 (T / Hr) × 1 (ton / billet) = 60 (s / billet), which is the shortest target time cycle. Now, the time required for flash butt welding is welding time 15 (s)
If the time required for clamping, positioning, etc. is 25 (s), the total time is 40 (s) and the remaining time is 20 (s). If the grinding time by the grinder is set to 15 (s), the deburring time will be 55 (s) in total when the flash butt welding machine and the grinder are integrated, and the remaining time is 5 (s). s) There is only one. Therefore, if the flash butt welder and the grinder are not returned to the standby position during the remaining time 5 (s), the time cycle will not be established, but it is impossible to perform the return traveling in such a short time. Therefore, it is impossible to realize the time cycle of 60 seconds in the case of the integrated type of the flash butt welding machine and the grinding machine.

Based on the results of the above time cycle examination, the present invention particularly examines the running operation of the flash butt welding machine and the grinder, and determines the continuous rolling method that best suits the actual factory capacity. That is the issue.

[0005]

First, in order to achieve the shortest target time cycle (60 sec), a flash butt welding machine and a running grinder in the present invention are configured as separate types, and a flash butt is used. Immediately after welding, the running grinder shall be moved back to pick up the billet weld. That is, the continuous rolling method according to the present invention descales the billet sent directly from the continuous casting machine, continuously welds it with a running flash butt welding machine, and removes burrs in the welded portion with a running grinding machine. Then, after heating and heating with an induction heating device, in the continuous rolling method of performing continuous rolling, the running flash butt welding machine and the running running grinder are configured to run independently, and during flash butt welding, The running flash butt welder and the running grinder run together, and performs flash butt welding while running a predetermined welding stroke, and at the end of welding, moves the running flash butt welder to a standby position. When returning, the running grinder accompanies the running flash butt welder and backs to pick up the welding part, and when the welding part arrives, the running grinder runs independently. Traveling by reversing the direction,
It is characterized in that the burr of the welded portion is ground and removed while traveling for a predetermined grinding stroke. By separating the running flash butt welder (hereinafter simply referred to as the welding machine) and the running grinder (hereinafter simply referred to as the grinding machine) as described above, the welding machine can return to the standby position 20 seconds after the completion of welding. That's fine, and it's a time cycle that is fully possible. In addition, since the grinder also gains time by arriving at the billet welded portion, there is a margin in recovery time.

The billet weight x (t) represented by the above equation (1)
The relationship between on / billet), rolling capacity y (T / Hr) and billet processing time cycle Ts is shown in FIG. In the graph of the figure, 11 is a line of Ts = 60 sec / billet, and 12
Is a line of Ts = 90 sec / billet. The billet processing time cycle is set to 60 seconds, which is the shortest target processing time determined from the current minimum rolling capacity of 60 (T / Hr) and the minimum billet weight of 1 (ton). On the other hand, the billet processing time cycle of 90 sec indicates the boundary between the integrated type and the separated type of the welding machine and the grinding machine as will be described later, but to be exact, the current rolling capacity is 60 to 100 (T / T). (Hr) and the billet weight range of 1 to 4 (ton). That is, in FIG. 1, a range 13 surrounded by ABCD is a separation type zone which cannot be established in a time cycle unless the welding machine and the grinding machine are separated, and a range 14 surrounded by CDEF is the welding machine and the grinding machine. The zone can be applied to either the integrated type or the separated type, but conversely, the integrated type can be applied only within this range 14.

Then, in the continuous rolling method of the present invention, a separate type or an integrated type of a welding machine and a grinding machine is determined based on the billet processing time cycle determined from the rolling capacity of the continuous rolling equipment and the billet weight. When the standard time cycle (for example, 90 seconds) or less, the separate type is used to shorten the time cycle, and when the standard time cycle or more, the integrated type is used. The burr is removed by grinding. In this way, the integrated type and the separated type can be used separately with the billet processing time cycle being 90 sec.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION When considering the layout of a welding machine and a grinding machine, they can be divided into two types, an integral type and a separate type, as described above. FIG. 2 shows an integrated type, which includes a welding machine 3 and a grinding machine 4.
This is the case when traveling as a unit. FIG. 3 shows a case of a separation type in which the welding machine 3 and the grinder 4 can run independently.

(1) Integral type The integral type is applied when the billet processing time cycle is 90 sec or more. The operation is as follows. That is, at the start of welding, the welding machine 3 and the grinder 4 are set to the positions shown in FIG.
It is in the standby position as shown in (a). From this standby position, the welder 3 and the grinder 4 together make a predetermined welding stroke SW.
The flash butt welding of the billet is carried out during traveling (see Fig. 2 (b)). That is, the traveling time of the stroke SW takes 40 seconds as described above. Next, the start of burr grinding starts after the arrival of the welded portion at the position at the end of this welding (c), and the grinding stroke SG
Grinding is completed while the welding machine 3 and the grinder 4 travel together (d). The arrival time (waiting time) of this weld is 10 seconds, and the running time of the grinder 4 is 15 seconds. Therefore, since it takes 65 seconds in total to finish flash butt welding and burr grinding, the remaining time is
90-65 = 25 sec, and in this 25 sec, the welding machine 3
And the grinder 4 must be returned to the standby position.
If there is sec, a sufficient time cycle is established.

(2) Separation type The separation type is applied when the billet processing time cycle is 90 sec or less. When the welder 3 and the grinder 4 are separated, the welder 3 can be immediately returned to the standby position immediately after the welding is completed as shown in FIG.
20 seconds remaining even if sec is the target time cycle
The sec can be used for the whole traveling time of the welding machine 3. Further, when the welding is completed, the grinder 4 also temporarily goes back with the welder 3 (reverse running distance L) to pick up the welded portion to the grinding start position (see FIG. 3 (c)). . After the welding is completed, if the grinder 4 waits until the welded portion comes to the grinding start position, the time cycle and the space are wasted so much. Therefore, the grinder 4 picks up the welded portion and gains time. . This reverse run time is about 5se
c. Therefore, the remaining time after grinding is 60
-(15 + 5) = 40 sec, and the grinding machine 4 can also return to the standby position with a sufficient margin.

As described above, in the case corresponding to the rolling equipment of 100 (T / Hr), in the case of the separation type, as shown in FIG. 1, the billet weight is 1.67ton (100 ÷ 3600 × 60 = 1.67ton / bi).
llet) or more, the cycle time becomes longer than 60 seconds, and the above method is also applicable. However, in the case of the integrated type, it can only be adapted to a billet having a weight of 2.5 tons or more. Therefore,
The integrated type may be used only in the case of 2.5 tons or more.

[0012]

EXAMPLES Specific examples of the method of the present invention are as follows. The setting conditions are as follows. Embodiment 1 FIG. Rolling capacity 90 (T / Hr) Billet weight / size 2 (ton), 154 x 154 (square) x 10.8 (m) Feeding cycle 80 (sec) Feeding speed 10.8 / 80 = 0.135 (m / s) ) Continuous casting machine (CCM) 3 strands, 0.135 / 3 × 60 = 2.7 (m / min) Rolling mill row Rough row 4 stands Intermediate row 8 stands Finishing row 4 stands Total 16 stands Product Rebar bar D13-D38 Example 2. Rolling capacity MAX.100 (T / Hr) Billet weight / size 3 (ton), 210 (round) × 11.1 (m) Feeding cycle 108 (sec) Feeding speed 11.1 / 108 = 0.103 (m / s) ) Continuous casting machine (CCM) 2 strands, 0.103 / 2 × 60 = 3.1 (m / min) Rolling mill Row Rough row 6 stands Intermediate row 6 stands Finishing row 6 stands Total 18 stands Block mill 10 stand Products Reinforcing bar D16-D41 Wire material 5.5 φ to 16 φ (mm)

(Embodiment 1) The reinforcing bar was rolled by using equipment having a layout as shown in FIG. In the figure, 1 is CCM, 2 is a table for cutting out billets one by one, 3 is a welding machine, 4 is a grinding machine for deburring,
5 is an induction heater, 6 is a rough row stand, 7 is an intermediate row stand, 8 is a finishing row stand, 9 is a cooling floor, 10
Is the adjustment and bundling equipment. This example is an embodiment in which the welding machine 3 and the grinder 4 are separated so that the billet processing time cycle is short. CCM equipment 1 has 3 strands, and billet size is 154 mm x 154 m
m, the length is 10.8 m, and the weight is 2.0 ton. A flash butt welding machine 3 is arranged directly downstream of the CCM. That is, the billets cut by each strand were cut out on a first-come-first-served basis by the table 2 installed in front of the welding machine and sequentially sent to the welding machine 3. At this time, the average temperature of the billet was about 914 ° C. . This welding machine 3
Has a traveling stroke of about 7 m and has a rolling capacity of 90 T / Hr. Billet entry speed to one stand 0.
The billet was welded while traveling synchronously at 135 m / s. The average time of the welding machine's time cycle at this time is Therefore, the total cycle time is 75 seconds on average.
After the welding is completed, an independent traveling grinder 4 is provided downstream of the welding.
Deburring of the welded part was performed. This deburring was performed with two sets of face-to-face grinders, and the deburring time was 21 seconds from the start of running from the standby position. In the case of continuous rolling of this separation system, the time cycle which becomes a neck was 75 seconds of the welding machine, and the traveling stroke of the welding machine was 6.2 m on average. Since the billet feeding cycle time at a rolling capacity of 90 T / Hr is 80 sec, the welding machine has a waiting time (margin time) of about 5 sec at the upstream standby position, and smooth rolling was possible. The temperature of the billet is the induction heater 5
The average temperature was 908 ° C. at the inlet of, and the induction heater 5 controlled and heated so that the billet temperature was 990 ° C. on average. The rolling line consists of four rough roll stands 6, eight intermediate row stands 7, and four finishing row stands 8.
It consists of a total of 16 units, and the maximum speed is the smallest size D1.
It was 12.9 m / s at the time of 3 rolling (slit rolling).
It is divided and cut into cooling floors 10 and, after cooling, precision bundling equipment 10
However, it was confirmed that all products continuously rolled by this method had uniform properties and sufficiently cleared the standard value.

(Example 2) This was carried out in equipment having a layout as shown in FIG. 5, and the reinforcing bar and wire rod were rolled. Since this embodiment is a large billet and has a margin of time cycle, the welding machine 3 and the grinding machine 4 are integrated. The CCM equipment 1 has two strands, the billet size is 210φ mm × 11.1 m, and the weight is 3.0 ton.
A welding machine 3 integrated with a grinding machine 4 and an induction heater 5 are arranged as a direct connection line downstream of the CCM as shown in the figure. Further, as a rolling facility for this HDR, a tandem rolling line is composed of 18 bar line rolling mills and 10 block mills 20 for wire rods. The billet directly sent from the CCM 1 is sent to the welder 3 integrated with the grinder 4 via the table 2 on the front surface of the welder. The average temperature of the billet at this time was about 925 ° C. The welding machine 3 moves together with the deburring grinder 4,
The maximum travel stroke is 8m. When the rolling line operates at a maximum capacity of 100 T / Hr, the billet feeding cycle is 108 sec. The approach speed to one stand was 0.103 m / s. The welding machine performs clamping, welding and deburring of the trailing billet while traveling in synchronization with this approach speed. The time cycle at that time was as follows. The total average cycle time is 102 seconds on average and 1
108-102 = 6 sec even at the maximum rolling of 00T / Hr
There was a margin at the standby position, and stable continuous rolling was performed. The running distance of the welding machine at this time was 7.2 m on average. The speed of the billet was 928 ° C on average at the inlet of the induction heater 5 after welding, and the billet was heated and rolled by the induction heater 5 to an average temperature of 990 to 1010 ° C. The rolling line was a bar line consisting of a total of 18 rough rows, 6 intermediate rows, and 6 finishing rows.
In addition to this, a block mill 20 consisting of 10 stands is arranged further downstream as rolling equipment for wire rods.
In the bar line, slit rolling of 8.9 m / s during D16 rolling and rolling of one strand at 12.4 m / s during D19 rolling were performed, and a product having uniform properties and sufficiently satisfying the standard values was stably rolled. . Further, in the rolling of the wire rod, the product to be continuously rolled is divided and cut at the tab shear 21,
A ton coil was manufactured, but it was possible to obtain a product having uniform properties and sufficient characteristics.

[0015]

As described above, according to the present invention, the welding machine and the grinding machine are configured as separate types that run independently, and
Since the grinding machine is run in reverse at the end of welding, the time cycle is established even when the billet weight is 1 to 2.5 tons and the rolling capacity is 60 to 100 tons. Rolling becomes possible. Also,
When using the welder and grinder integrated type, it can only be used when the billet weight is within the integrated zone of FIG. 1 for rolling capacity.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the billet weight, rolling ability, and billet processing time cycle in the present invention.

FIG. 2 is an explanatory diagram showing an operation in the case of the welder / grinder integrated type of the present invention.

FIG. 3 is an explanatory view showing an operation in the case of the welding machine / grinding machine separate type of the present invention.

FIG. 4 is an explanatory diagram showing a layout of equipment according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a layout of equipment according to a second embodiment of the present invention.

[Explanation of symbols]

 3 Welding machine 4 Grinding machine

Claims (2)

[Claims] 1. A billet sent directly from a continuous casting machine is descaled, continuously welded by a running flash flash butt welding machine, burrs at the welded portion are ground and removed by a running grinding machine, and an induction heating device is used. In a continuous rolling method of performing continuous rolling after heating and heating, the running flash butt welding machine and the running running grinder are configured to be able to run independently, and during flash butt welding, the running flash butt welding is performed. Machine and the running grinder run together and perform flash butt welding while running a predetermined welding stroke, and at the end of welding, when the running flash butt welder is returned to the standby position, the running The inter-grinding machine accompanies the running flash butt welder and backs, and goes to the welding part.When the welding part arrives, the running grinder runs independently by reversing the running direction. Continuous rolling method, characterized by grinding deburring of the welded portion while traveling a predetermined grinding stroke. 2. A billet sent directly from a continuous casting machine is descaled, continuously welded by a running flash butt welding machine, burrs at the welded portion are ground and removed by a running grinding machine, and an induction heating device is used. In the continuous rolling method of performing continuous rolling after heating and heating, based on the rolling time of the billet processing time cycle determined from the rolling capacity and billet weight of the continuous rolling equipment, the running flash butt welding machine and the running grinding machine Separate type or integrated type, shorten the time cycle by using the separate type in the case of the standard time cycle or less, use the integrated type in the case of the standard time cycle or more, flash butt welding of billet, respectively. Next, a continuous rolling method characterized by grinding and removing burrs from the welded portion.