Surface scarfing device and surface scarfing method

Abstract

To provide a technique that can scarf a whole surface ranging from a front end to a rear end of a steel material.SOLUTION: A surface scarfing device (10), which scarfs a surface of a steel material being conveyed, from a heating furnace to a roughing mill, comprises: a conveying part (12); a laser emitting part (14a); a gas blowing part (16a) that blows gas composed mainly of oxygen to an area on the steel material to which the laser emitting part emits a laser beam; and a control part (20) that controls the laser emitting part and the gas blowing part, in response to conveyance of the steel material by the conveying part. The control part executes: a preparing process for making the laser emitting part start to emit a laser beam and making the gas blowing part start to blow gas; and a scarfing process for scarfing the surface of the steel material into a predetermined thickness, by making the laser emitting part continuously emit laser beams and making the gas blowing part continuously blow gas onto a whole surface ranging from the front end part to the rear end part of the steel material being conveyed by the conveying part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a surface scrubbing apparatus and a surface scrubbing method. [Background technology]

[0002] Examples of steel materials that are subjected to laser cutting include billets that are rolled to be processed into products, such as slabs, billets, and blooms. During the manufacturing process of these billets, cracks may occur on the surface of the billets due to external forces, thermal strain, or the like. These cracks are defects, and it is desirable that the surface of the billets be free of defects in order to maintain the quality of the products manufactured from the billets.

[0003] Therefore, techniques have been proposed for removing defects on the surface of steel billets. For example, Patent Document 1 discloses a technique for scarifying the surface of iron material using a laser and oxygen gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 53-4750 Summary of the Invention [Problem to be solved by the invention]

[0005] The use of electric furnaces is being considered as a method for producing iron sources with the aim of decarbonizing. In this method, a large amount of scrap is fed into the furnace, and it is expected that the scrap will contain a large amount of copper (Cu), such as from motors. Cu is a so-called tramp element, and is an element that cannot be removed during the blowing process, and is contained as is in steel products such as billets.

[0006] When the Cu content in steel increases, a problem called red embrittlement occurs. Red embrittlement occurs when scale forms on the surface of steel in the high-temperature oxygen atmosphere of a heating furnace, causing Cu that was dissolved in the steel to be expelled from the scale and then to concentrate in a liquid state at the interface between the scale and the base metal. Specifically, the liquid Cu that has concentrated at the interface between the scale and the base metal infiltrates the grain boundaries of the base metal, causing microcracks on the surface of the base metal. These microcracks on the surface of the base metal become apparent during the subsequent hot rolling process, posing a quality problem.

[0007] Here, since the microcracks caused by the Cu-enriched layer are dispersed and distributed over the entire surface of the steel, it is necessary to dissolve and remove the entire surface of the steel (both the front and back sides). In addition, in order to remove the Cu-enriched layer generated in the heating furnace and the microcrack layer caused by Cu infiltration before rolling the steel, it is desirable to complete the dissolution process in a short time while the steel is being transported from the heating furnace to the roughing mill, before the steel cools down from the specified temperature.

[0008] Here, in gas cutting, a common type of cutting, a pool of molten steel, which serves as a heat source, is formed on the surface of the steel, so cutting cannot be done from the end of the steel. Therefore, the starting end, which is not cut, is separately ground and repaired using a grinder, a second process.

[0009] When attempting to perform laser cutting on steel material between the heating furnace and the roughing mill, there is no time to perform laser cutting twice on the steel material that has just left the heating furnace or to grind and repair the edges in order to prevent the steel material from cooling over time, making it difficult to use conventional gas laser cutting, which requires the formation of a basin. It is also difficult to secure a large enough space between the heating furnace and the roughing mill to perform the laser cutting twice.

[0010] The technology disclosed in Patent Document 1 relates to laser cutting. Patent Document 1 is a technology for cutting any part of the surface of a steel material, but has the problem that it does not support laser cutting of the entire surface of the steel material from the front end to the rear end.

[0011] From the viewpoint of laser cutting steel material in a short time, it is desirable to complete laser cutting of the entire surface of the steel material from the front end to the rear end in one go.

[0012] An object of one aspect of the present invention is to realize a technology for performing thermal cutting on the entire surface of a steel material from the front end to the rear end. [Means for solving the problem]

[0013] In order to solve the above-mentioned problems, a surface rake-cutting device according to one aspect of the present invention is a surface rake-cutting device that rakes the surface of a steel material being transported from a heating furnace to a roughing rolling mill, and includes a transport unit that transports the steel material in a transport direction from the heating furnace to the roughing rolling mill, a laser irradiation unit that irradiates the steel material with laser light, a gas spraying unit that sprays a gas containing oxygen as a main component onto an area on the steel material that is irradiated with laser light by the laser irradiation unit, and a control unit that controls the laser irradiation unit and the gas spraying unit in response to the transport of the steel material by the transporting unit. and a control unit that controls the laser irradiation unit, and the control unit performs a preparatory process of starting irradiation of laser light from the laser irradiation unit and spraying of gas from the gas spraying unit before the front end of the steel material being transported by the transporting unit reaches the range of the laser light irradiated from the laser irradiation unit, and a cutting process of cutting the surface of the steel material to a predetermined thickness by continuously irradiating laser light from the laser irradiation unit and spraying gas from the gas spraying unit from the front end to the rear end of the steel material being transported by the transporting unit.

[0014] In order to solve the above problems, a surface laser-cutting method according to one aspect of the present invention is a surface laser-cutting method for laser-cutting the surface of a steel material being transported from a heating furnace to a roughing rolling mill, the method using a surface laser-cutting device including: a conveying unit that conveys the steel material in a conveying direction from the heating furnace to the roughing rolling mill; a laser irradiation unit that irradiates the steel material with laser light; and a gas spraying unit that sprays a gas mainly composed of oxygen onto an area on the steel material that is irradiated with laser light by the laser irradiation unit. The surface laser-cutting method includes: a preparation processing step of starting irradiation of laser light from the laser irradiation unit and spraying of gas from the gas spraying unit before a front end of the steel material being transported by the conveying unit reaches a range of the laser light irradiated from the laser irradiation unit; and a laser-cutting processing step of laser-cutting the surface of the steel material to a predetermined thickness by continuously irradiating the laser light from the laser irradiation unit and spraying of gas from the gas spraying unit from the front end to the rear end of the steel material being transported by the conveying unit. [Effects of the Invention]

[0015] According to one aspect of the present invention, the entire surface of the steel material from the front end to the rear end can be thermally cut. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram showing a configuration example of a surface rake-cutting device according to an embodiment of the present invention; [Figure 2] 3A and 3B are diagrams illustrating an example of a configuration regarding the arrangement of a laser irradiation unit and laser light according to an embodiment of the present invention. [Figure 3] FIG. 1 is a flowchart showing an example of the flow of a surface scarification method according to an embodiment of the present invention. [Figure 4] 10A to 10C are diagrams illustrating an example of the operation of the surface rake-cutting device according to an embodiment of the present invention. [Figure 5] 10A to 10C are diagrams illustrating an example of the operation of the surface rake-cutting device according to an embodiment of the present invention. [Figure 6] 1 is a diagram showing a configuration example of a surface rake-cutting device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0017] [Embodiment 1] Hereinafter, one embodiment of the present invention will be described in detail.

[0018] The surface cutting device 10 according to this embodiment is, as an example, a device that uses laser cutting, which allows cutting of the entire surface of a steel material from its front end to its rear end, all at once, using laser cutting, which is capable of starting cutting the steel material simultaneously with irradiation of a laser.

[0019] (Configuration of surface rake device 10) Fig. 1 is a diagram showing an example of the configuration of a surface scalding apparatus 10. The surface scalding apparatus 10 is an apparatus that scalds the surface of a steel material 100 being transported from a heating furnace to a roughing mill. As shown in Fig. 1, the surface scalding apparatus 10 includes a transport unit 12, a laser irradiation unit 14a, a gas blowing unit 16a, and a control unit 20.

[0020] The steel material 100 may be, for example, a steel material to be rolled after being cooled after processing in a continuous casting machine or the like, and then reheated in a heating furnace and rolled. The steel material 100 may be in the form of a variety of shapes and sizes, such as a steel billet such as a slab, a billet, or a bloom, or a steel pipe or wire rod. The steel material 100 may be produced from scrap or the like, and may contain tramp elements such as Cu in its composition.

[0021] That is, the steel material 100 in this embodiment is produced in a continuous casting machine and then heated to a predetermined temperature in a heating furnace. When rolling the steel material 100, it is necessary to perform rolling at an appropriate temperature required to refine the material, and after leaving the heating furnace, it is necessary to perform spall cutting within a short time so that rolling can begin in a state where the steel material is maintained at the predetermined appropriate temperature.

[0022] Therefore, there is no time to carry out the cutting in multiple steps.

[0023] (Transport unit 12) The conveying section 12 conveys the steel material 100 in a conveying direction from the heating furnace toward the roughing mill. Here, the steel material 100 may be heated in a heating furnace, and then the surface scale may be removed using a known technique before being conveyed to the surface laser cutting device 10. Also, a known descaling device that removes surface scale may be installed immediately before the surface laser cutting device. In other words, laser cutting can be performed immediately after the surface scale is removed using a known technique.

[0024] Each of the conveying units 12 may include, for example, conveying rollers and a driving device. For example, as shown in Fig. 1, the steel materials 100 are placed on the conveying rollers provided in the plurality of conveying units 12, and the steel materials 100 are conveyed by rotating the conveying rollers using a driving device. In Fig. 1, the conveying units 12 convey the steel materials 100 in a conveying direction D.

[0025] (Laser irradiation unit 14a) The laser irradiation unit 14a irradiates the steel material 100 with laser light L. As shown in FIG. 1, the laser irradiation unit 14a is, for example, connected to a laser oscillator 142 via an optical fiber cable F. For example, the laser irradiation unit 14a may have a linear focusing optical head that focuses the laser light in a line. Furthermore, for example, the laser irradiation unit 14a may be arranged opposite the surface of the steel material 100 and configured to irradiate the surface of the steel material 100 with laser light L.

[0026] FIG. 2 is a diagram showing an example of the arrangement of the laser irradiation units 14a and the configuration regarding the laser light L. The multiple laser irradiation units 14a may be arranged side by side in the width direction of the steel material 100, as shown in FIG. 2, for example. Here, the multiple laser irradiation units 14a may be arranged, for example, so that the ends of the focused spots of adjacent laser irradiation units 14a overlap in the width direction of the steel material 100. In other words, the multiple laser irradiation units 14a may be arranged, for example, so that convex stripes that become residual cutting are not generated in the region 104 between the points irradiated with the laser light L by adjacent laser irradiation units 14a. Furthermore, the multiple laser irradiation units 14a may irradiate the laser light L over the entire length in the width direction of the steel material 100, for example.

[0027] For example, as shown in Fig. 2, while the steel material 100 is conveyed in the conveying direction D relative to a plurality of laser irradiation units 14a, the plurality of laser irradiation units 14a may irradiate the steel material 100 with laser light L over the entire width of the steel material 100, thereby irradiating the entire surface of the steel material 100 with laser light L. The laser-cutting completed portion 102 in Fig. 2 is a portion of the steel material 100 where laser cutting has been completed after irradiation with laser light L.

[0028] (Gas spraying section 16a) The gas blowing unit 16a blows a gas containing oxygen as a main component onto an area on the steel material 100 that is irradiated with laser light L by the laser irradiation unit 14a. The gas blowing unit 16a includes, as an example, a gas blowing port 162a. The gas blowing unit 16a may blow gas onto the steel material 100 via the gas blowing port 162a, for example. The proportion of oxygen contained in the gas blown by the gas blowing unit 16a may be set as appropriate. Specific examples of gas components other than oxygen (O2) contained in the gas blown by the gas blowing unit 16a include inert gases such as helium (He) or argon (Ar), carbon dioxide (CO2), and nitrogen (N2).

[0029] Here, the thermal cutting process by the laser irradiation unit 14a and the gas blowing unit 16a will be described. Fe on the surface of the steel material 100 reacts with the irradiation of laser light L by the laser irradiation unit 14a and oxygen contained in gas G by the gas blowing unit 16a to generate FeO. FeO has a lower melting point than Fe and is characterized by the generation of reaction heat as it is generated. The surface of the steel material 100 is thermally cut by blowing away the thermal cutting material SC, which is mainly composed of molten FeO, by the gas blowing unit 16a.

[0030] For example, when the steel material 100 contains a large amount of scrap, microcracks due to a Cu-enriched layer are distributed over the entire surface of the steel material 100 heated in a heating furnace, and therefore it is preferable to be able to perform a laser cutting on both the front and back surfaces of the steel material 100 in one go. Therefore, a second laser irradiation unit 14b and a second gas blowing unit 16b may be provided to perform a laser cutting on a surface opposite to the surface of the steel material 100 that is subjected to a laser cutting by the laser irradiation unit 14a and the gas blowing unit 16a.

[0031] (Second laser irradiation unit 14b) The surface slicing apparatus 10 may further include, for example, a second laser irradiation unit 14b. For example, when the laser irradiation unit 14a irradiates the front surface of the steel material 100 with laser light L, the second laser irradiation unit 14b may irradiate the back surface of the steel material 100 with laser light L. In other words, the second laser irradiation unit 14b may irradiate the surface of the steel material 100 that is paired with the surface of the steel material 100 irradiated by the laser irradiation unit 14a with laser light.

[0032] Here, if the laser irradiation unit 14a and the second laser irradiation unit 14b are arranged to face each other, there is a possibility that the laser light of the other will enter and damage the optical head. In order to prevent damage to the optical heads of the laser irradiation unit 14a and the second laser irradiation unit 14b, the laser irradiation unit 14a and the second laser irradiation unit 14b may be arranged, for example, offset from each other in the conveyance direction of the steel material 100. As an example, the second laser irradiation unit 14b may be arranged further forward in the conveyance direction D of the steel material 100 than the laser irradiation unit 14a, as shown in FIG. 1 . Also, as another example, the laser irradiation unit 14a may be arranged further forward in the conveyance direction D of the steel material 100 than the second laser irradiation unit 14b.

[0033] Other configurations of the second laser irradiation unit 14b in this embodiment may be similar to, for example, the configuration of the above-mentioned laser irradiation unit 14a in which laser light L is irradiated onto the back surface of the steel material 100 instead of the front surface, so explanations will be omitted here.

[0034] (Second gas blowing section 16b) The surface laser-cutting apparatus 10 may further include, for example, a second gas blowing unit 16b. The second gas blowing unit 16b may, for example, blow a gas containing oxygen as a main component onto an area on the steel material 100 that is irradiated with laser light L by the second laser irradiation unit 14b. The second gas blowing unit 16b includes, as an example, a second gas blowing port 162b. The configuration of the second gas blowing unit 16b and the second gas blowing port 162b in this embodiment may be the same as, for example, the configuration of the above-mentioned gas blowing unit 16a and gas blowing port 162a in which gas is blown onto the back surface of the steel material 100 instead of the front surface, and therefore a description thereof will be omitted here.

[0035] (First shielding portion 18a) The surface sintering device 10 may further include, for example, a first shielding portion 18a. When the laser irradiation portion 14a and the second laser irradiation portion 14b are arranged offset from each other in the conveying direction of the steel material 100, the inclusion of the first shielding portion 18a can prevent the laser light from being reflected at unintended locations during the preparation process described below. The first shielding portion 18a may, for example, block the laser light L emitted from the laser irradiation portion 14a. Furthermore, the first shielding portion 18a may, for example, be arranged to face the laser irradiation portion 14a across the steel material 100 conveyed by the conveying portion 12, as shown in FIG. 1 . Furthermore, the second gas blowing portion 16b may, for example, include the first shielding portion 18a. When second gas blowing unit 16b is installed facing laser irradiation unit 14a across steel material 100, second gas blowing unit 16b having first shielding unit 18a can prevent damage to second gas blowing unit 16b. Here, the surface of first shielding unit 18a may be made of a material that easily absorbs laser light. Also, for example, the surface of first shielding unit 18a may be coated with black paint or the like to increase the laser absorption rate.

[0036] (Second shielding portion 18b) The surface sintering device 10 may further include, for example, a second shielding portion 18b. When the laser irradiation unit 14a and the second laser irradiation unit 14b are arranged offset from each other in the conveying direction of the steel material 100, the provision of the second shielding portion 18b can prevent the laser light from being reflected at unintended locations during the preparation process described below. The second shielding portion 18b may, for example, block the laser light L emitted from the second laser irradiation unit 14b. Furthermore, the second shielding portion 18b may, for example, be arranged to face the second laser irradiation unit 14b across the steel material 100 conveyed by the conveying unit 12. Furthermore, the gas blowing unit 16a may, for example, include the second shielding portion 18b. When gas blowing unit 16a is installed facing second laser irradiation unit 14b across steel material 100, damage to gas blowing unit 16a can be avoided by providing second shielding unit 18b. Here, the surface of second shielding unit 18b may be made of, for example, a material that easily absorbs laser. Furthermore, for example, the surface of second shielding unit 18b may be coated with black paint or the like to increase the laser absorption rate.

[0037] (Control unit 20) The control unit 20 controls the laser irradiation unit 14a and the gas blowing unit 16a in response to the transportation of the steel material 100 by the transport unit 12. Specifically, the control unit 20 executes a preparation process and a laser cutting process before the front end of the steel material 100 transported by the transport unit 12 reaches the reach of the laser light L irradiated from the laser irradiation unit 14a. That is, the control unit 20 starts the irradiation of laser light from the laser irradiation unit 14a and the blowing of gas from the gas blowing unit 16a (i) before the front end of the steel material 100 transported by the transport unit 12 reaches the reach of the laser light L irradiated from the laser irradiation unit 14a, or (ii) at the same time as the front end of the steel material 100 reaches the reach of the laser light L. The control unit 20 may further control, for example, the transport unit 12, the second laser irradiation unit 14b, and the second gas blowing unit 16b. Furthermore, the control unit 20 may control the laser irradiation unit 14a and the second laser irradiation unit 14b via the laser oscillator 142, for example.

[0038] The control unit 20 may be configured with an electronic circuit including, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), etc. Furthermore, the control unit 20 may include, for example, an electronic circuit such as a PLD (Programmable Logic Device) or an ASIC (Application Specific Integrated Circuit) instead of or in addition to the CPU.

[0039] (Surface cutting method S1 flow) The surface rake-cutting method S1 executed by the surface rake-cutting device 10 will be described with reference to FIGS.

[0040] Fig. 3 is a flow diagram showing an example of the flow of the surface laser-cutting method S1. As shown in Fig. 3, the surface laser-cutting method S1 includes a preparation process (step) S10 and a stopping process (step) S12.

[0041] 4 is a diagram showing an example of the operation over time of the surface rake-cutting apparatus 10. For the sake of convenience of explanation, some components of the surface rake-cutting apparatus 10 are omitted in the illustration of FIG.

[0042] FIG. 5 is a diagram showing an example of operation of the surface scratching device 10 in the scratching process.

[0043] (Preparation process) In step S10 of FIG. 3 , the control unit 20 starts the irradiation of laser light L from the laser irradiation unit 14a and the spraying of gas G from the gas spraying unit 16a. This start process is a preparation process executed by the control unit 20 before the front end of the steel material 100 being transported by the transport unit 12 reaches the range of the laser light L irradiated from the laser irradiation unit 14a. The control unit 20 may start the irradiation of laser light L from the laser irradiation unit 14a and the spraying of gas G from the gas spraying unit 16a, for example, in response to information about the position of the steel material 100 being transported by the transport unit 12 or a user operation. Information about the position of the steel material 100 may be determined, for example, using an optical sensor that detects the arrival of light from a light source and the blocking of light from the light source by an object. Furthermore, information about the position of the steel material 100 may be determined, for example, by calculating the travel distance of the steel material 100 with reference to the travel speed of the steel material 100 and the travel time from a predetermined position. Furthermore, the control unit 20 may start the irradiation of the laser light L from the laser irradiation unit 14a and the spraying of the gas G from the gas spraying unit 16a at the same time, or may start them at different times.

[0044] The preparation process may also be performed at the same time that the front end of the steel material 100 being transported by the transport unit 12 reaches the range of the laser light L irradiated from the laser irradiation unit 14a.

[0045] Furthermore, the control unit 20 may set conditions such as the output amount of the laser light L, the amount of gas G blown, and the purity of the oxygen gas contained in the gas G based on a predetermined thickness to be laser-cut on the surface of the steel material 100, and then start irradiating the laser light L from the laser irradiation unit 14a and spraying the gas G from the gas spraying unit 16a. For example, the purity of the oxygen gas contained in the gas G may be controlled to adjust the thickness to be laser-cut on the steel material 100 in the laser-cutting process. The predetermined thickness to be laser-cut on the surface of the steel material 100 may be, for example, 0.2 mm or more and 2 mm or less.

[0046] ST1 in Fig. 4 shows the state of the surface laser-cutting apparatus 10 during the preparation process. Here, time t1 in ST1 in Fig. 4 is the time point before the front end of the steel material 100 being transported in the transport direction D by the transport unit 12 reaches the range of the laser light L irradiated from the laser irradiation unit 14a.

[0047] (At the start of cutting on the surface of the steel material 100) ST2 in Fig. 4 shows the state of the surface laser-cutting apparatus 10 at time t2 (t2>t1), when the front end of the steel material 100 being transported by the transport unit 12 reaches the range of the laser light L irradiated from the laser irradiation unit 14a. In ST2 in Fig. 4, laser cutting of the front surface of the steel material 100 is started from the front end using the laser irradiation unit 14a and the gas blowing unit 16a.

[0048] The control unit 20 performs a cutting process to cut the surface of the steel material 100 to a predetermined thickness by continuously irradiating laser light L using the laser irradiation unit 14a and spraying gas G using the gas spraying unit 16a from the front end to the rear end of the steel material 100 transported by the transporting unit 12.

[0049] Furthermore, since it is preferable for the control unit 20 to complete the laser cutting from the front end to the rear end of the front and rear surfaces of the steel material 100 in a single laser cutting operation, the control unit 20 may also perform laser cutting on the rear surface of the steel material 100. For the rear surface of the steel material 100, time t2 in ST2 in FIG. 4 is the time point before the front end of the steel material 100 being transported in the transport direction D by the transport unit 12 reaches the range of the laser light L irradiated from the second laser irradiation unit 14b. In other words, for the rear surface of the steel material 100, ST1 and ST2 shown in FIG. 4 are the times before the front end of the steel material 100 reaches the range of the laser light L irradiated from the second laser irradiation unit 14b, and therefore the control unit 20 can start the preparation process. Therefore, as shown in ST2 of Figure 4, for example, in the preparation process, the control unit 20 may start the irradiation of laser light L from the second laser irradiation unit 14b and the spraying of gas G from the second gas spraying unit 16b before the front end of the steel material 100 being transported by the transporting unit 12 reaches the range of the laser light L irradiated from the second laser irradiation unit 14b.

[0050] (Surface cutting treatment on the front and back surfaces of the steel material 100) ST3 in Fig. 4 shows the state of surface laser-cutting apparatus 10 at time t3 (t3>t2), which is the point in time after the front end of steel material 100 being transported by transport unit 12 has reached the range of laser light L irradiated from second laser irradiation unit 14b. In ST3 in Fig. 4, laser-cutting of the back surface of steel material 100 has also started from the front end.

[0051] For example, in a cutting process, the control unit 20 may cut the surface of the back side of the steel material 100 by continuously irradiating laser light L from the second laser irradiation unit 14b and spraying gas G from the second gas spraying unit 16b from the front end to the rear end of the steel material 100.

[0052] In ST3 of FIG. 4, the surface of the front side and the surface of the back side of the steel material 100 have been completely scarified up to the scarification-completed portion 102.

[0053] As described above, the control unit 20 performs the laser cutting process from the front end to the rear end of the steel material 100, thereby completing the laser cutting of the entire front and back sides of the steel material 100 in one go. Because the surface of the steel material 100 can be laser cut in one go, there is no need to use a surface laser cutting device multiple times, and there is also no need to transport the steel material over long distances.

[0054] Fig. 5 is a diagram showing an example of the operation of the surface laser-cutting device 10 for the laser-cutting process on both the front surface and the back surface of the steel material 100, and also showing details of ST3 in Fig. 4. In Fig. 5, gas G is sprayed from the gas spraying port 162a provided in the gas spraying section 16a and the second gas spraying port 162b provided in the second gas spraying section 16b.

[0055] Here, for example, when the steel material 100 includes a Cu-enriched layer on the surface side, which has a higher concentration of Cu components than the base material, it is preferable that the Cu-enriched layer be removed in the spalling treatment performed by the control unit 20. The predetermined thickness by which the surface of the steel material 100 is spalled may be, for example, the minimum thickness necessary to remove the Cu-enriched layer included in the surface of the steel material 100.

[0056] (Stop processing) In step S12 of FIG. 3 , the control unit 20 stops the irradiation of the laser light L from the laser irradiation unit 14a and the spraying of the gas G from the gas spraying unit 16a after the rear end of the steel material 100 being transported by the transport unit 12 has passed through the range reached by the laser light L from the laser irradiation unit 14a. The control unit 20 may stop the irradiation of the laser light L from the laser irradiation unit 14a and the spraying of the gas G from the gas spraying unit 16a, for example, in response to information regarding the position of the steel material 100 being transported by the transport unit 12 or a user operation. The information regarding the position of the steel material 100 may be determined, for example, using an optical sensor that detects the arrival of light from a light source and the blocking of light from the light source by an object. Furthermore, the information regarding the position of the steel material 100 may be determined, for example, by calculating the travel distance of the steel material 100 with reference to the travel speed of the steel material 100 and the travel time from a predetermined position.

[0057] In addition, the control unit 20 may stop the irradiation of laser light L from the second laser irradiation unit 14b and the spraying of gas G from the second gas spraying unit 16b, for example, after the rear end of the steel material 100 being transported by the transporting unit 12 has passed through the range of the laser light L from the second laser irradiation unit 14b.

[0058] (Effects of the surface scraping device 10) As described above, the surface scalding device 10 is a surface scalding device that scalps the surface of steel material being transported from the heating furnace to the roughing rolling mill, and the surface scalding device 10 includes a transport unit that transports the steel material in the transport direction from the heating furnace to the roughing rolling mill, a laser irradiation unit that irradiates the steel material with laser light, and a gas spraying unit that sprays a gas containing oxygen as a main component onto an area on the steel material that is irradiated with laser light by the laser irradiation unit, and a control unit that controls the laser irradiation unit and the gas spraying unit in response to the transport of the steel material by the transporting unit. and a control unit for controlling the laser beam irradiation unit to irradiate the steel material conveyed by the conveying unit, the control unit executing a preparatory process for starting irradiation of laser beam from the laser irradiation unit and spraying of gas from the gas spraying unit before the front end of the steel material conveyed by the conveying unit reaches the range of the laser beam irradiated from the laser irradiation unit, and a laser cutting process for laser cutting the surface of the steel material to a predetermined thickness by continuously irradiating the steel material with laser beam from the laser irradiation unit and spraying of gas from the gas spraying unit from the front end to the rear end of the steel material conveyed by the conveying unit. This allows the entire surface of the steel material from the front end to the rear end to be laser cut.

[0059] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0060] (Configuration of the surface rake-cutting device 10 according to this embodiment) 6 is a diagram showing a configuration example of the surface rake-cutting apparatus 10 according to this embodiment. In comparison with the surface rake-cutting apparatus 10 according to embodiment 1, the surface rake-cutting apparatus 10 according to this embodiment has the following features: The second laser irradiation unit 14b is disposed forward of the gas blowing unit 16a in the conveying direction D of the steel material 100, and The second shielding unit 18b is disposed separately from the gas blowing unit 16a so as to face the second laser irradiation unit 14b across the steel material 100 being transported by the transport unit 12. are different for each.

[0061] Other configurations of the surface rake-cutting apparatus 10 in this embodiment may be the same as those of the surface rake-cutting apparatus 10 in the first embodiment, for example.

[0062] 〔summary〕 A surface slag cutting device according to a first aspect of the present invention is a surface slag cutting device that slags the surface of a steel material being transported from a heating furnace to a roughing rolling mill, and the surface slag cutting device includes a transport unit that transports the steel material in a transport direction from the heating furnace to the roughing rolling mill, a laser irradiation unit that irradiates the steel material with laser light, and a gas spraying unit that sprays a gas containing oxygen as a main component onto an area on the steel material that is irradiated with laser light by the laser irradiation unit, and controls the laser irradiation unit and the gas spraying unit in response to the transport of the steel material by the transporting unit. and a control unit for controlling the laser beam irradiation unit to irradiate the steel material conveyed by the conveying unit, the control unit executing a preparatory process for starting irradiation of laser beam from the laser irradiation unit and spraying of gas from the gas spraying unit before the front end of the steel material conveyed by the conveying unit reaches the range of the laser beam irradiated from the laser irradiation unit, and a laser cutting process for laser cutting the surface of the steel material to a predetermined thickness by continuously irradiating the steel material with laser beam from the laser irradiation unit and spraying of gas from the gas spraying unit from the front end to the rear end of the steel material conveyed by the conveying unit. This allows the entire surface of the steel material from the front end to the rear end to be laser cut.

[0063] A surface laser-cutting device according to a second aspect of the present invention is the same as that of the first aspect, wherein the predetermined thickness is 0.2 mm or more and 2 mm or less, thereby enabling the steel surface to be laser-cut to an appropriate thickness.

[0064] A surface laser-cutting apparatus according to a third aspect of the present invention is the same as that of either the first or second aspect, wherein the steel material includes a Cu-enriched layer on the surface side thereof, the Cu-enriched layer having a higher Cu concentration than the base material, and the Cu-enriched layer is removed in the laser-cutting treatment, thereby removing the Cu-enriched layer on the steel material surface.

[0065] A surface laser-cutting apparatus according to a fourth aspect of the present invention is any of the first to third aspects, and comprises a second laser irradiation unit that irradiates laser light onto a surface of the steel material that is paired with the surface of the steel material irradiated by the laser irradiation unit, and a second gas spraying unit that sprays a gas mainly composed of oxygen onto the area on the steel material that is irradiated with laser light by the second laser irradiation unit, wherein the control unit, in the preparation process, starts irradiation of laser light from the second laser irradiation unit and spraying of gas from the second gas spraying unit before the front end of the steel material being transported by the transporting unit reaches the range of the laser light irradiated from the second laser irradiation unit, and the control unit, in the laser-cutting process, continuously irradiates the laser light from the second laser irradiation unit and sprays gas from the second gas spraying unit from the front end to the rear end of the steel material, thereby laser-cutting the surface on the back side of the steel material. As a result, the surface laser cutting device can laser cut the entire front and back surfaces of the steel material from the front end to the rear end.

[0066] A surface slag cutting device according to a fifth aspect of the present invention is the same as that of the fourth aspect, in that the laser irradiation unit and the second laser irradiation unit are arranged offset from each other in the conveying direction of the steel material, thereby preventing damage to the optical heads of the laser irradiation unit and the second laser irradiation unit.

[0067] A surface slag cutting device according to a sixth aspect of the present invention is the device of the fourth or fifth aspect, further comprising: a first shielding unit that is disposed opposite the laser irradiating unit across the steel material transported by the transporting unit and that shields the laser light irradiated from the laser irradiating unit; and a second shielding unit that is disposed opposite the second laser irradiating unit across the steel material transported by the transporting unit and that shields the laser light irradiated from the second laser irradiating unit. This prevents the laser light from being reflected in unintended locations.

[0068] A seventh aspect of the present invention relates to the surface scrubbing apparatus of the sixth aspect, wherein the gas blowing unit has the second shielding unit, or the second gas blowing unit has the first shielding unit, thereby making it possible to avoid damage to the gas blowing unit or the second gas blowing unit.

[0069] A surface laser-cutting method according to an eighth aspect of the present invention is a surface laser-cutting method for laser-cutting the surface of a steel material being transported from a heating furnace to a roughing mill, the method including a conveying section for conveying the steel material in a conveying direction from the heating furnace to the roughing mill, a laser irradiation section for irradiating the steel material with laser light, and a gas spraying section for spraying an oxygen-based gas onto the area of ​​the steel material irradiated with the laser light by the laser irradiation section, using a surface laser-cutting device including: a preparation step for starting irradiation of laser light from the laser irradiation section and spraying of gas from the gas spraying section before the front end of the steel material being transported by the conveying section reaches the range of the laser light irradiated from the laser irradiation section; and a laser-cutting processing step for laser-cutting the surface of the steel material to a predetermined thickness by continuously irradiating the laser light from the laser irradiation section and spraying of gas from the gas spraying section from the front end to the rear end of the steel material being transported by the conveying section. This allows the entire surface of the steel material from the front end to the rear end to be laser-cut.

[0070] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0071] 10 Surface cutting equipment 12 Conveyor 14a Laser irradiation part 14b Second laser irradiation unit 16a Gas spraying section 16b Second gas spraying section 18a First shielding part 18b Second shielding part 20 Control Unit 142 Laser Oscillator 162a Gas nozzle 162b Second gas nozzle

Claims

1. A surface scrubbing device that scrubs the surface of a steel material being transported from a heating furnace to a roughing rolling mill, a conveying unit that conveys the steel material in a conveying direction from the heating furnace toward the roughing mill; a laser irradiation unit that irradiates the steel material with laser light; a gas blowing unit that blows a gas containing oxygen as a main component onto an area on the steel material that is irradiated with laser light by the laser irradiation unit; a control unit that controls the laser irradiation unit and the gas spraying unit in response to the transport of the steel material by the transport unit; Equipped with The control unit a preparation process for starting irradiation of laser light from the laser irradiation unit and spraying of gas from the gas spraying unit before a front end of the steel material being transported by the transport unit reaches a reachable range of the laser light irradiated from the laser irradiation unit; A surface cutting device that performs a cutting process to cut the surface of the steel material to a predetermined thickness by continuously irradiating laser light from the laser irradiation unit and spraying gas from the gas spraying unit from the front end to the rear end of the steel material transported by the conveying unit.

2. The surface scraping device according to claim 1 , wherein the predetermined thickness is 0.2 mm or more and 2 mm or less.

3. the steel material includes a Cu-enriched layer on the surface side, the Cu-enriched layer having a higher concentration of Cu than the base material, The surface laser cutting apparatus according to claim 1 , wherein the Cu-enriched layer is removed in the laser cutting treatment.

4. a second laser irradiation unit that irradiates a laser beam onto a surface of the steel material that is paired with the surface of the steel material irradiated by the laser irradiation unit; a second gas blowing unit that blows a gas containing oxygen as a main component onto an area on the steel material that is irradiated with laser light by the second laser irradiation unit; Equipped with In the preparation process, the control unit before a front end of the steel material being transported by the transport unit reaches a reachable range of the laser light irradiated from the second laser irradiation unit, the irradiation of the laser light from the second laser irradiation unit and the spraying of the gas from the second gas spraying unit are started; The control unit, in the surface cutting process, 2. The surface cutting device according to claim 1, wherein the surface on the back side of the steel material is cut by continuously irradiating laser light from the second laser irradiation unit and spraying gas from the second gas spraying unit from the front end to the rear end of the steel material.

5. The surface rake-cutting device according to claim 4 , wherein the laser irradiation unit and the second laser irradiation unit are arranged to be offset from each other in the conveying direction of the steel material.

6. a first shielding unit that is disposed opposite the laser irradiation unit across the steel material transported by the transporting unit and that shields the laser light irradiated from the laser irradiation unit; a second shielding unit that is disposed opposite the second laser irradiation unit across the steel material transported by the transporting unit and that shields the laser light irradiated from the second laser irradiation unit; The surface scraping apparatus according to claim 4 or 5, comprising:

7. The gas blowing unit has the second shielding unit, or The surface scraping device according to claim 6 , wherein the second gas spraying section has the first shielding section.

8. A surface scrubbing method for scrubbing the surface of a steel material being transported from a heating furnace to a roughing rolling mill, a conveying unit that conveys the steel material in a conveying direction from the heating furnace toward the roughing mill; a laser irradiation unit that irradiates the steel material with laser light; a gas blowing unit that blows a gas containing oxygen as a main component onto an area on the steel material that is irradiated with laser light by the laser irradiation unit; Using a surface scraping device comprising: a preparation step of starting irradiation of laser light from the laser irradiation unit and spraying of gas from the gas spraying unit before a front end of the steel material being transported by the transport unit reaches a reachable range of the laser light irradiated from the laser irradiation unit; a laser beam irradiation unit irradiating the steel material from the front end to the rear end of the steel material being transported by the transport unit, and a gas spraying unit spraying the gas continuously from the front end to the rear end of the steel material, thereby performing a thermal cutting process to thermally cut the surface of the steel material to a predetermined thickness; A surface scraping method comprising:

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