JP2005254317A - Coating method and apparatus for self-fluxing alloy, and continuous casting mold using the same, and manufacturing method for mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for inexpensively and firmly coating a copper plate with a self-fluxing alloy, and to obtain a continuous casting mold having a high wear resistance and a long life by using the copper plate coated by the above method and apparatus. <P>SOLUTION: The coating apparatus and the method are provided in which copper plate to be coated with the self-fluxing alloy is irradiated with laser and a self-fluxing alloy powder is continuously fed to the irradiated part. The coating layer is formed by irradiating the self-fluxing alloy with a laser beam having a wavelength of 630-940 nm, an energy density of at least 10 kW/cm<SP>2</SP>, and a heat input imparted to the coating part of 5-15 kJ/cm, and then by performing a remelting treatment. The continuous casting mold using the copper plate which is coated with the self-fluxing alloy with the use of the above apparatus and method is also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus and method for coating a self-fluxing alloy on a copper plate, a continuous casting mold using the coated copper plate, and a method for producing the same.

  The base material of the continuous casting mold for steel is made of copper, and if it is left as it is, it is very worn against sliding of slab and powder. Therefore, Ni-based or Co-based plating is usually applied as a countermeasure against wear, but the hardness is lower than that of the sprayed coating, and the wear resistance is insufficient. In particular, since the lower part of the mold is severely worn, the application of Ni-based self-fluxing alloys has been studied as a countermeasure against wear. There is a problem that the heat deformation of the base material becomes large and it becomes impossible to assemble the processed copper plate as a mold. In the case of a slab continuous casting mold, the long side exceeding 400 mm cannot be made, and only the short side is applied. ing.

  The remelting treatment is usually carried out by heating the sprayed coating with a flame of a gas burner. However, in this method, oxidation degradation of the coating is also a problem in addition to the thermal deformation described above. Further, when covering a large area with a gas burner, the heating state is likely to be non-uniform, and the occurrence of a part where the adhesion strength of the film is insufficient, and further the generation of pinholes, are also problematic. Furthermore, since the coating thickness after remelting tends to be non-uniform, a method of grinding after forming a sprayed coating that is thicker than the required thickness is generally used, resulting in poor yield of the sprayed material and increased construction costs. There was also a problem of doing.

  As countermeasures for the above problems, as disclosed in Patent Document 1 and Patent Document 2, for example, self-fluxing alloy is subjected to supersonic flame spraying (remelting process omitted), or WC / NiCr, WC / Co, CrC / NiCr. There is provided a method for constructing the steel by supersonic flame spraying.

  Further, as a means for preventing the oxidative deterioration of the thermal spray coating during the remelting process, as disclosed in Patent Document 3, a method of applying an antioxidant to a self-fluxing alloy and fusing, or Patent Document 4 As disclosed in Japanese Patent Application Laid-Open No. H11-260, a method for fusing by applying an electron beam to a self-fluxing alloy has been proposed. Since both of these perform fusing, they cannot be applied to the long side of a continuous casting mold.

Furthermore, Patent Document 5 discloses a method in which a self-fluxing alloy is sprayed or laminated and then remelted with a laser beam to coat. In this method, the surface is smoothed by melting, but sufficient heat may not be transmitted to the vicinity of the coating interface, and the self-fluxing alloy does not melt sufficiently in this part, and voids are formed in the coating material and peeled off. There was a concern. In addition, there is a concern that the cost becomes high because there are two heating steps of thermal spraying and remelting.
JP-A-8-225917 JP-A-8-187554 JP-A-10-121126 JP 11-226700 A JP 2003-320441 A

  An object of the present invention is to provide a method and an apparatus for coating a self-fluxing alloy on a copper plate at low cost and firmly, and to obtain a continuous casting mold having a high wear resistance and a long life using the copper plate obtained thereby. For the purpose.

In order to achieve the above object, the present inventor has extensively studied a coating method and a self-fluxing alloy with a semiconductor laser beam, and has obtained the following knowledge.
(1) While the semiconductor laser has a low absorptivity with respect to copper as a base material for coating, it is high with respect to Ni, Cr, and Fe, which are main components of self-fluxing alloys. Thereby, copper is not heated very much even if it receives the same irradiation, but the self-fluxing alloy is heated.
(2) When the powder is heated and coated with laser light while supplying the powder, since the powder is not microscopically continuous, the light reaches deeply, thereby sufficiently heating the coating interface.

The inventor made the following invention based on the above findings.
(1) A surface plate for fixing a copper plate covering a self-fluxing alloy, a semiconductor laser device for irradiating a laser beam toward the copper plate, and a self-fluxing alloy powder continuously applied to a portion where the laser device irradiates a laser beam. A self-fluxing alloy coating apparatus comprising a supply apparatus.

(2) After supplying self-fluxing alloy particles to the surface of the copper plate and irradiating the self-fluxing alloy with laser light having a wavelength of 630 to 940 nm and an energy density of at least 10 kW / cm ² to melt the self-fluxing alloy A self-fluxing alloy coating method characterized by solidifying and forming a coating layer.

  (3) The self-fluxing alloy coating method according to (2) above, wherein the amount of heat input to the irradiated surface coating portion by the laser light is 5 kJ / cm or more and 15 kJ / cm or less.

  (4) The self-fluxing alloy according to (2) or (3), wherein the surface of the copper plate is coated or laminated with a deoxidizer as a base treatment, and self-fluxing alloy particles are supplied thereon. Coating method.

  (5) One or more coating layers of Ni, Co, Fe plating layers or alloy plating layers based on these, or Ni or Cu-Ni alloy brazing material were formed on the surface of the copper plate. The self-fluxing alloy coating method according to any one of the above (2) to (4), wherein the base material is a base material.

  (6) The self-fluxing alloy is Ni, Co or Fe-based self-fluxing alloy, or chromium carbide, tungsten carbide, vanadium carbide, niobium carbide, zirconium carbide is added to these self-fluxing alloys. The method for coating a self-fluxing alloy according to any one of (2) to (5) above, wherein

  (7) A method of coating a self-fluxing alloy on a continuous casting mold, wherein the copper continuous casting mold is coated by the method according to any one of (2) to (6).

  (8) A casting mold for continuous casting, characterized by being produced using a copper plate coated with a self-fluxing alloy by the method according to any one of (2) to (6).

  In the present invention, since the heating is not performed twice such as spraying and remelting, the process is shortened and the coating can be obtained efficiently. In addition, since the self-fluxing alloy powder is sufficiently melted and coated, the surface of the copper plate is smoothly coated with no defects. Furthermore, the copper plate coated in this way has high wear resistance by taking advantage of the characteristics of the self-fluxing alloy, and the service life as a casting mold for casting is greatly improved.

The present invention will be described in detail below using the best mode.
FIG. 1 is a perspective view showing the best mode of the present invention. The surface of the copper plate 6 fixed to the surface plate is irradiated with the irradiation light 4 emitted from the semiconductor laser device 1, and the self-fluxing alloy powder 2 is supplied to the irradiation part to perform the melting treatment, and the self-fluxing alloy film 5 is formed.

  The semiconductor laser device 1 is preferably attached to a feeding device and scans the surface of the coating material while maintaining a constant distance from the coating material at a constant speed. Moreover, the powder supply apparatus 3 moves following the scanning of the irradiation light 4 of the laser. It is preferable that the powder supply device 3 has a mechanism that constantly supplies the self-fluxing alloy powder 2 in a fixed amount.

  If the particle size of the self-fluxing alloy powder is small, it will be dissipated more than the range of the laser irradiation light at the time of supply and the yield will be lowered. Also, troubles such as clogging of the supply device are likely to occur. On the other hand, when the particle size is large, the ratio of the surface area to the weight of the powder is small, so that the area exposed to the laser light is reduced, so that the melting treatment is not efficiently performed. Therefore, the particle size of the self-fluxing alloy powder used here is preferably 10 μm or more and 200 μm or less.

  FIG. 2 shows a coating method disclosed in Patent Document 5. A self-fluxing alloy coating is formed on the surface of the copper plate 6 by thermal spraying, and the coating surface is irradiated with irradiation light 4 emitted from the laser device 1 to perform remelting treatment. In this coating method, two heating steps of thermal spraying and remelting are necessary, and the number of processes increases. In addition, since the surface of the self-fluxing alloy coating formed in advance is irradiated with laser light, the surface area on which the self-fluxing alloy is irradiated with laser light is smaller than the irradiation of the powdered self-fluxing alloy in this method. The coating formation efficiency is low.

In general, a practical semiconductor laser has a laser wavelength of 630 to 940 nm, and can output an energy density of at least 10 kW / cm ² . In order to make the difference in absorption rate between copper and self-fluxing alloy remarkable, the laser wavelength is preferably 800 nm or more.

  The amount of heat input that the laser beam gives to the irradiated surface coating portion is given by the laser output and the feed rate of the laser device. If the amount of heat input is small, the self-fluxing alloy will not melt sufficiently and a coating will not be formed. If the heat input is large, the self-fluxing alloy evaporates, resulting in poor coating formation, reduced performance of the coating layer due to oxidation, and cracking of the coating layer due to rapid heating and quenching. Therefore, it is desirable that the amount of heat input that the laser beam gives to the irradiated surface coating portion be in the range of 5 kJ / cm to 15 kJ / cm in order to form a good coating layer.

  Also, copper plate is generally prone to surface oxidation and corrosion. Before coating the self-fluxing alloy, the surface of the copper plate is pretreated by shot blasting, grinder processing, brushing, etc. to remove the oxide film, etc. It is desirable to keep it. Furthermore, a more effective coating layer can be obtained by applying or laminating a deoxidizer, supplying self-fluxing alloy particles thereon and irradiating it with laser light to adhere the self-fluxing alloy to the copper plate. Power is also improved.

  In addition, as a base treatment for improving the adhesion of the self-fluxing alloy to the copper plate as described above, the surface of the copper plate is Ni, Co, Fe plating layer or an alloy plating layer based on these, or Ni or Cu- If any one or two or more coating layers of a brazing material of Ni alloy are formed, it is possible to prevent oxidation of the copper plate surface, and the plating material is excellent in adhesion with a self-fluxing alloy and more preferable. A coating layer can be obtained.

  The self-fluxing alloy forming the coating layer is preferably a Ni-, Co- or Fe-based self-fluxing alloy. These are densified by a melting process and have good adhesion to the copper plate surface. In addition, if these self-fluxing alloys are added with one or more of chromium carbide, tungsten carbide, vanadium carbide, niobium carbide, zirconium carbide, the hardness of the coating layer, that is, the wear resistance is improved. A preferable coating layer can be obtained.

  The surface of the continuous casting mold 1 having a width of 2500 mm and a height of 900 mm is ground-treated by shot blasting using the apparatus of the present invention shown in FIG. Layer 5 was formed under various conditions. The four Ni-based self-fluxing alloys are films made of Ni, Cr, B, Si, etc. and having a Vickers hardness of 600 to 800 after the melting treatment. As the self-fluxing alloy powder 2, spherical particles produced by a gas atomizing method with a particle size in the range of 40 μm to 130 μm were used. The laser device 1 used for the melting treatment was a semiconductor laser having a wavelength of 805 nm and a maximum output of 4 kW. Further, the beam shape of the laser irradiation light 4 was a rectangle, and a long side of 6 mm × short side of 0.25 mm was used. The distance between the tip of the laser device 1 and the coating surface was 40 mm in accordance with the focal length of the laser device used for this.

実施例における、条件１および２は本発明の被覆法にてレーザーの照射条件を与えてＮｉ基自溶性合金の被覆層を形成した例である。条件３はＮｉ基自溶性合金粉末の供給量を変化させて、被覆層を形成した例である。また、条件４および５は、銅板表面に下地処理として膜厚０．５〜１ｍｍのＮｉメッキおよびＣｏ−Ｎｉメッキを施した上で、Ｎｉ基自溶性合の被覆層を形成した例である。条件６は、クロム炭化物をＮｉ基自溶性合金４種に配合した材質の被覆層を、本発明の方法で形成した例である。 Table 1 compares the examples of the present invention with the comparative examples. In Table 1, “SFA” is an abbreviation for self-fluxing alloy.

Conditions 1 and 2 in the examples are examples in which a coating layer of a Ni-based self-fluxing alloy was formed by applying laser irradiation conditions in the coating method of the present invention. Condition 3 is an example in which the coating layer is formed by changing the supply amount of the Ni-based self-fluxing alloy powder. Conditions 4 and 5 are examples in which a Ni-based self-soluble coating layer was formed on the copper plate surface after Ni plating and Co-Ni plating with a film thickness of 0.5 to 1 mm were applied as a base treatment. Condition 6 is an example in which a coating layer made of a material in which chromium carbide is blended with four kinds of Ni-based self-fluxing alloys is formed by the method of the present invention.

  Condition 7 in the comparative example is an example in which a coating layer of a Ni-based self-fluxing alloy was formed under laser irradiation conditions different from the conditions 1 and 2 of the example. Condition 8 is an example in which a Ni-based self-fluxing alloy powder is laminated in advance with a layer thickness of about 1 mm on the surface of a copper plate, and a melting process is performed using a gas burner. Conditions 9 and 10 are those in which a Ni-based self-fluxing alloy and a coating layer in which chromium carbide is blended are formed by thermal spraying on the copper plate surface by high-speed flame spraying, and the remelting treatment is not performed. High-speed flame spraying is a method in which oxygen and petroleum are used, and a sprayed powder is fired from a gun at a supersonic speed of 1 km / second or more and sprayed onto a base material.

  When a coating layer according to the conditions of the above examples was prepared and used for an actual continuous casting mold, the coating layer of any of the examples had a good coating state, compared to the conventional Ni plating, the lower layer. It was shown that the lifetime until the copper mold base material was exposed due to abrasion was more than doubled. In particular, four kinds of coating layers of Ni-based self-fluxing alloy containing chromium carbide of Condition 6 showed a life three times longer than that of Ni plating. On the other hand, when the coating layers under conditions 9 and 10 in the comparative example were inspected after use for the same period as the wear life of the Ni plating, partial peeling occurred and continuous use was impossible.

It is the perspective view which showed the best form of this invention. It is the perspective view which showed the coating | cover form disclosed by patent document 5. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor laser apparatus 2 Self-fluxing alloy powder 3 Powder supply apparatus 4 Irradiation light 5 Completed self-fluxing alloy coating layer 6 Copper plate fixed to the surface plate

Claims (8)

A surface plate for fixing a copper plate covering a self-fluxing alloy, a semiconductor laser device for irradiating a laser beam toward the copper plate, and a device for continuously supplying a self-fluxing alloy powder to a portion where the laser device irradiates a laser beam A self-fluxing alloy coating apparatus comprising: The self-fluxing alloy particles are supplied to the surface of the copper plate, and the self-fluxing alloy is irradiated with laser light having a wavelength of 630 to 940 nm and an energy density of at least 10 kW / cm ² to melt the self-fluxing alloy and then solidify. A method for coating a self-fluxing alloy, comprising forming a coating layer. 3. The self-fluxing alloy coating method according to claim 2, wherein the amount of heat input to the irradiated surface coating portion by the laser light is 5 kJ / cm or more and 15 kJ / cm or less. 4. The self-fluxing alloy coating method according to claim 2, wherein a deoxidizer is applied or laminated on the surface of the copper plate as a base treatment, and self-fluxing alloy particles are supplied thereon. Based on the surface of the copper plate formed with one or more coating layers of Ni, Co, Fe plating layer or alloy plating layer based on these, or brazing material of Ni or Cu-Ni alloy The method for coating a self-fluxing alloy according to any one of claims 2 to 4, wherein the material is a material. The self-fluxing alloy is a Ni-, Co- or Fe-based self-fluxing alloy, or one or more of chromium carbide, tungsten carbide, vanadium carbide, niobium carbide, zirconium carbide added to these self-fluxing alloys. The method for coating a self-fluxing alloy according to any one of claims 2 to 5. A method of coating a self-fluxing alloy on a continuous casting mold, wherein the copper continuous casting mold is coated by the method according to any one of claims 2 to 6. A casting mold for continuous casting produced by using a copper plate coated with a self-fluxing alloy by the method according to any one of claims 2 to 6.

Images