JP2010163686A - Surface treatment apparatus and surface treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treatment apparatus which can enhance a transfer rate of a projection material and decrease surface roughness, when surface-treating an article to be treated by jetting the projection material thereto while induction-heating the article to be treated. <P>SOLUTION: This surface treatment apparatus includes: a chamber 110; a gas-supplying part 142 for introducing nitrogen gas into the chamber 110; a support 120 which is arranged in the chamber 110 and supports the article to be treated W; an induction heating coil 130 which is arranged around the support 12 and heats the article to be treated W; a high-frequency-wave-applying unit 200 which supplies a high-frequency electric current to the induction heating coil 130 and makes the induction heating coil 130 induction-heat the article to be treated W; and a jet nozzle 140 which jets the projection material together with an inert gas or jets an inert gas, toward the support 120. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a surface treatment apparatus and a surface treatment method for performing surface treatment by injecting a projection material while inductively heating an object to be treated, and particularly relates to a technique capable of simultaneously improving the transfer rate of a projection material and reducing the surface roughness. .

  2. Description of the Related Art Conventionally, surface treatment apparatuses that perform surface treatment by spraying a projection material (fine particles) such as metal particles onto a steel material are known.

  For example, a technique is known in which Mn is evaporated and removed by heating in a vacuum atmosphere after shot peening to increase the Cr concentration of the Cr-enriched layer on the surface (see, for example, Patent Document 1). That is, in a state where the base material (object to be processed) has a steel ball (projection material) inside the stainless steel pipe, a shot peening process is performed in which the steel ball collides with the inner surface of the base material by applying vibration to the base material. The Cr-enriched layer is generated on the inner surface of the base material P by promoting the surface diffusion of Cr in the base material.

  After the shot peening treatment, the base material after the treatment is sent to a vacuum heating furnace and heated, for example, in an atmosphere at a temperature of 900 to 1200 ° C. for about 30 minutes, about the Cr-enriched layer on the inner surface of the base material, Mn is removed by evaporation.

  That is, using the fact that the boiling point of Mn is low among the chemical components described above, only Mn is evaporated and removed from the Cr-enriched layer. Note that the Mn component is a useful metal component for preventing the occurrence of stress cracking during the production and welding of stainless steel. The influence on the physical properties can be ignored.

In addition, a technique for forming an oxide protective film after shot peening is known (see, for example, Patent Document 2). That is, the projection material may be any metal that forms a protective film with excellent oxidation resistance, and Al, Si, etc. are considered in addition to Cr. And the powder of these metals, the alloy containing these metals, or these mixtures are used as a projection material. The average particle size of the projection material is preferably 50 to 300 μm. Examples of the base material include heat resistant steels such as ferritic heat resistant steels including high Cr ferritic heat resistant steels, austenitic heat resistant steels, and stainless steels. As the shot peening apparatus, a commonly used apparatus can be used. A range of 6.0 to 8.5 kg / cm ² is considered for the spray pressure of the shot peening treatment. The spraying time varies depending on the size of the target base material. For example, in the case of a test piece having a size of 10 × 20 × 2 mm, 5 seconds or more per test piece is preferable. In this way, the Cr adhesion layer on the base material can be processed by a generally used apparatus, and the projection material is also used at an extremely low cost because only the amount necessary for shot peening is used.

Next, a preliminary oxidation treatment is performed on the base material on which the Cr adhesion layer is formed. In this treatment, a Cr oxide protective film is formed on the base material by heat treatment at 600 ° C. to 800 ° C. in an air atmosphere or in a low oxygen atmosphere such as Ar, H ₂ , or N ₂ gas. The The heat treatment time is considered to be about 1 hour in the air atmosphere and about 20 to 100 hours in the low oxygen atmosphere. As a result, an oxide protective film having a thickness of 0.3 μm or less is formed on the surface of the base material.

  Further, a high-frequency current is passed through the coil to inductively heat the surface of the processing object to a predetermined temperature, and particles are injected onto the surface of the heated processing object by moving the processing object and the coil relative to each other. A compound layer is formed by a thermochemical reaction between the surface of the object and the particles to bond the particles (for example, see Patent Document 3). Note that this document clearly states that an expensive apparatus that covers an object to be treated with a shielding gas such as an inert gas is unnecessary, and the surface treatment apparatus has a simple and inexpensive structure.

On the other hand, what improved the transfer rate of the metal particle by adjusting the surface temperature of a to-be-processed object is known (for example, refer patent document 4).
JP-A-5-331670 JP 2005-298878 A JP 2006-70320 A JP 2008-127647 A

  The surface treatment apparatus described above has the following problems. That is, there is a problem that the film thickness of the projection material cannot be obtained sufficiently. In addition, in the case of adjusting the surface temperature of the object to be processed, although the bond between the particles to be processed and the object to be processed is sufficiently obtained, the amount of oxide generated increases as the temperature increases, and the surface roughness increases. There was a problem of increasing the length. Furthermore, there has been a problem that the carbon content of the object to be treated combines with oxygen in the atmosphere (decarburization), and the mechanical properties deteriorate.

  Therefore, the present invention can improve the transfer rate of the projection material, reduce the surface roughness, and maintain the mechanical properties when the surface treatment is performed by injecting the projection material while inductively heating the workpiece. An object of the present invention is to provide a surface treatment apparatus and a surface treatment method.

  In order to solve the problems and achieve the object, the surface treatment apparatus and the surface treatment method of the present invention are configured as follows.

  In a surface treatment apparatus for performing surface treatment by spraying a projection material onto an object to be processed, a chamber, an inert gas introduction unit that introduces an inert gas into the chamber, and the chamber are disposed in the chamber. A supporting unit for supporting, an induction heating coil disposed around the supporting unit for heating the workpiece, and a high-frequency applying unit for induction heating the workpiece by supplying a high-frequency current to the induction heating coil. , A projection material injection unit for injecting the projection material together with the inert gas toward the support unit, a cooling unit for cooling the object to be processed, and an inert gas introduced from the inert gas introduction unit, The inside of the chamber is replaced with the inert gas, a high-frequency current is supplied from the high-frequency applying unit to the induction heating coil to heat the object to be processed to a predetermined temperature, and the object to be processed is heated to a predetermined temperature. The Injecting the projection material and the inert gas from the projection material injection unit to supply a high-frequency current to the induction heating coil in a state where the object to be processed is maintained at the predetermined temperature, and the cooling unit to A control unit for cooling the object to be processed is provided.

  In a surface treatment method in which a projection material is sprayed onto an object to be processed contained in a chamber to perform surface treatment, a replacement step of replacing the inside of the chamber with an inert gas and heating the object to a predetermined processing temperature A heating step, a transfer step of projecting the projection material toward the object to be processed in the predetermined temperature range, and transferring the projection material to the surface of the object to be processed, and an inert gas being sprayed onto the object to be processed And a cooling step for cooling.

  In a surface treatment apparatus for injecting a projection material onto a workpiece to perform surface treatment, the chamber, a neutral gas introduction unit for introducing a neutral gas into the chamber, and the chamber are disposed in the chamber. A supporting unit for supporting, an induction heating coil disposed around the supporting unit for heating the workpiece, and a high-frequency applying unit for induction heating the workpiece by supplying a high-frequency current to the induction heating coil. , A projection material injection unit that injects the projection material together with the neutral gas toward the support unit, a cooling unit that cools the object to be processed, and a neutral gas introduced from the neutral gas introduction unit. The inside of the chamber is replaced with the neutral gas, a high-frequency current is supplied from the high-frequency applying unit to the induction heating coil to heat the object to be processed to a predetermined temperature, and the object to be processed is heated to the predetermined temperature. After the projection Injecting the projection material and the neutral gas from the injection unit and supplying the induction heating coil with a high-frequency current in a state in which the object to be processed is maintained at the predetermined temperature, and the object to be processed by the cooling unit A control unit for cooling is provided.

  In a surface treatment method in which a projection material is sprayed onto an object to be processed contained in a chamber to perform a surface treatment, a replacement step of replacing the inside of the chamber with a neutral gas, and the object to be processed are heated to a predetermined processing temperature. A heating step, a transfer step of projecting the projection material toward the object to be processed in the predetermined temperature range, and transferring the projection material to the surface of the object to be processed; And a cooling step for cooling.

  In a surface treatment method for spraying a projection material onto a workpiece to be treated in a chamber to perform a surface treatment, a replacement step of replacing the inside of the chamber with an inert gas or a neutral gas, and a predetermined treatment of the workpiece. A heating step of heating to a temperature, a transfer step of projecting the projection material toward the object to be processed in the predetermined temperature range, and transferring the projection material to the surface of the object to be processed; and a cooling liquid on the object to be processed And a cooling step for rapid cooling by spraying.

  According to the present invention, it is possible to improve the transfer rate of the projection material, reduce the surface roughness, and maintain the mechanical characteristics when the surface treatment is performed by injecting the projection material while inductively heating the workpiece. It becomes possible.

  FIG. 1 is a sectional view showing a schematic configuration of a surface treatment apparatus 100 according to an embodiment of the present invention. The surface treatment apparatus 100 is an apparatus that performs surface treatment by spraying a projection material while induction-heating the workpiece W. Here, as the workpiece W, for example, a steel material that is a magnetic material can be targeted. In particular, a steel material mainly composed of iron is suitable. On the other hand, examples of the projecting material include metals such as iron, chromium and aluminum, alloys such as chromium-nickel and tungsten carbide-cobalt, metal oxides such as ceramics such as alumina, silica and zirconia, silicon carbide and silicon nitride. Examples thereof include metal compounds containing metals that are ceramics. Moreover, as a projection material, the thing by which the average particle diameter was adjusted to several micrometers-several hundred micrometers, for example is utilized.

  As shown in FIG. 1, the surface treatment apparatus 100 includes a chamber 110 formed in an airtight manner. Into the chamber 110, a support base 120 on which the workpiece W is placed, an induction heating coil 130 provided around the support base 120, and a projection material or an inert gas are injected toward the support base 120. An injection nozzle (projection material injection unit / inert gas injection unit) 140 and a water cooling mechanism (water cooling unit) 170 for injecting cooling water CL are provided.

  The chamber 110 is provided with an exhaust port 111 for exhausting the gas in the chamber 110 and an oxygen concentration meter 112 for measuring the oxygen concentration of the gas in the chamber 110. The output of the oxygen concentration meter 112 is connected to the control unit 300 described later. Furthermore, the chamber 110 is provided with a globe 113 for operating the inside from the outside.

  A temperature sensor 121 that measures the surface temperature of the workpiece W is provided on the support stand 120. The output of the temperature sensor 121 is connected to the control unit 300.

  The induction heating coil 130 is connected to a high frequency application device 200 provided outside the chamber 110, and a high frequency current having a predetermined frequency is applied thereto.

  An injection nozzle 140 is provided in the chamber 110 and includes a nozzle 141 directed toward the support base 120. The injection nozzle 140 is connected to a gas cylinder 160 for supplying an inert gas such as argon gas and a flow rate / pressure regulating valve 161 via an electromagnetic valve 142. In the flow rate valve / pressure regulating valve 161, the inert gas is injected at an injection speed of, for example, several tens of m / sec to several thousand m / sec. In addition, you may control not as an injection speed but as an injection pressure (for example, 0.5 MPa).

  The flow valve / pressure regulating valve 161 is further connected to a feeder line 151 connected to the particle feeder 150. The feeder line 151 is provided with particle feeder adjusting valves 152 to 154, and the projection material P is supplied to the injection nozzle 140.

  The water cooling mechanism 170 is provided with an injection nozzle 171 provided in the chamber 110 and a cooling water supply device 172 that supplies the cooling water CL to the injection nozzle 171.

  The high frequency applying device 200 applies high frequency currents having a single frequency or a plurality of frequencies to the induction heating coil 130 to inductively heat the workpiece W.

  In FIG. 1, reference numeral 300 denotes a control unit that controls each part of the surface treatment apparatus 100. The control unit 300 controls the high-frequency application device 200, the electromagnetic valve 142, the particle feeder adjustment valves 152 to 154, and the cooling water supply device 172 based on information such as operator settings, preset programs, and sensor outputs. And adjusting the heating of the workpiece W, the injection speed / injection amount of the projection material P, the injection amount of the inert gas, the injection amount / injection timing of the cooling water CL, and the like.

  As an example of the control by the control unit 300, only the inert gas is injected from the nozzle 141 to replace the inside of the chamber 110 with the inert gas, and the high frequency current is supplied from the high frequency applying device 200 to the induction heating coil 130 to be processed. W is heated to a predetermined temperature, and after the workpiece W is heated to a predetermined temperature, the projection material and the inert gas are ejected from the nozzle 141 and the workpiece W is maintained in a predetermined temperature. Control is performed such that a high-frequency current is supplied to the heating coil 130 and only the inert gas is injected from the nozzle 141 to cool the workpiece W.

  The surface treatment apparatus 100 configured as described above operates as follows. That is, only the inert gas is ejected from the nozzle 141, the air in the chamber 110 is discharged from the exhaust port 111, and is replaced with the inert gas. When the oxygen concentration in the chamber 110 by the oximeter 112 becomes a predetermined value or less (for example, 0.3% or less), a high frequency is applied from the high frequency application device 200 to the induction heating coil 130 as shown in FIGS. An electric current is supplied to heat the workpiece W to a predetermined temperature.

  Next, the shot peening process is performed by injecting the projection material P and the inert gas from the nozzle 141. At this time, high frequency current is supplied to the induction heating coil 130 so that the output of the temperature sensor 121 is maintained at 900 ° C. The projection material P collides with the surface of the workpiece W by the injection (FPP) of the projection material P.

  Next, the cooling is performed by cooling or spraying only the inert gas from the nozzle 141 onto the workpiece W.

  On the other hand, chromium, which is a material that can be combined and combined with a steel material in order to obtain desired properties such as imparting corrosion resistance and wear resistance, etc., is used as the workpiece W, such as a steel material that is a magnetic material. Corrosion resistance is improved by injecting metal particles, metal compounds, metal oxide particles, or the like mainly containing a metal such as the projection material P.

  In addition, since the surface treatment apparatus 100 performs the shot peening process and the heating process at the same time, the surface diffusion of the projection material is promoted. In addition, since heating is performed in the same apparatus, it can be processed in a short time.

  In the cooling process, the workpiece W may be cooled by spraying the coolant CL from the spray nozzle 171 using the coolant supply device 172. In this case, as will be described later, the hardness of each part of the workpiece W can be controlled as compared with the case where the hardness is allowed to cool or gas cool (air cool).

  Next, the optimum surface treatment conditions using the surface treatment apparatus 100 are examined. As processing conditions, those for which the replacement gas is changed and those for which the temperature pattern is changed are performed. Further, S45C was used as the material W to be processed.

  For the replacement gas, argon gas and nitrogen gas were used as the inert gas. In addition, air was examined as a comparative example. As shown in FIG. 2, when argon is used, the projection material P is transferred to the surface with a sufficient thickness. Also in the case where nitrogen gas is used, the projection material P is transferred to the surface with a sufficient thickness as shown in FIG. Note that since there is very little oxygen gas in the chamber 110, almost no oxide scale that inhibits transfer is generated. Therefore, when an inert gas is used, it is possible to improve the transfer rate of the projection material P, reduce the surface roughness, and maintain the mechanical characteristics.

  On the other hand, as shown in FIG. 4, when the projection is performed in the atmosphere, the projection material P is scattered in the oxide scale, the transfer rate of the projection material P is low, and the surface roughness is reduced / mechanical. The characteristic cannot be maintained.

  2 is treated under the conditions of argon-Cr900-FPP 10 seconds-cooling, FIG. 3 is treated with nitrogen-Cr900-FPP 10 seconds-cooling, and FIG. 4 is treated with air-Cr900-FPP 10 seconds-cooling. .

  5 to 8 show the element analysis on the surface after the surface treatment. FIGS. 5 and 6 show Cr mapping, and FIGS. 7 and 8 show oxygen mapping. As shown in FIG. 5, a sufficient Cr layer is formed when substituted with argon gas, and almost no Cr layer is seen when the atmosphere is kept as shown in FIG. As shown in FIG. 7, when the argon gas is substituted, the oxide layer is thin, and as shown in FIG. 8, a thick oxide layer is seen in the atmosphere.

  5 is processed under the conditions of argon-Cr900, FIG. 6 is the atmosphere-Cr900, FIG. 7 is the argon-Cr900, and FIG. 8 is the atmosphere-Cr900.

  The transfer is a phenomenon in which a part of the projection material adheres to the processing material when the projected particles and the processing material collide (contact), that is, the projection material main element moves to the processing material. Means that.

Specifically, in an argon atmosphere, as shown in FIG. 9A, after the projection is performed in a state where no oxide is formed on the surface during heating, the particle transfer layer is formed to a certain thickness from the surface when cooled. (Cr and Cr ₂ O ₃ ).

On the other hand, in the air atmosphere, as shown in FIG. 9B, an oxide is formed on the surface at the time of heating, and after projection is performed, when cooled, the particle transfer layer (Cr ₂ O ₃₎ is thinly formed on the oxide layer. ) Will be formed.

  Moreover, FIG. 10A-FIG. 10C have shown the case where it changed about temperature conditions. That is, this phenomenon is observed when the heating temperature is 500 ° C. or higher shown in FIG. 10A. However, in view of the efficiency of the apparatus and the like in mass production, 700 ° C. or higher shown in FIG. 900 ° C. is more preferable. Therefore, it can be appropriately selected depending on conditions and the like.

  Furthermore, as shown in FIG. 11, when comparing the Vickers hardness when the conditions are performed in a nitrogen atmosphere, which is a neutral gas, the hardness is increased compared to the case where both nitrogen gas and air are untreated, Those subjected to surface treatment with nitrogen gas are reduced in hardness by decarburization. In addition, if a water cooling process is given so that it may mention later, the quenching effect will arise and the fall of the surface hardness by decarburization can be suppressed (refer FIGS. 33-35). Therefore, even with an inert gas or a neutral gas, the hardness can be increased to the same extent as in the atmosphere.

Furthermore, FIG. 12A shows a case where a crystal structure analysis is performed. In the atmosphere, an oxide of the workpiece W (Fe ₂ O ₃ , FeO) and a double oxide (FeCr ₂ O ₄ ) of the projection material P and the workpiece W are formed, and in an argon gas atmosphere, An oxide (Cr ₂ O ₃ , FeCr ₂ O ₄ ) of the projection material P is formed. The projection at room temperature is also shown for comparison. As can be seen from FIG. 12A, it is clear that the ratio of the Cr compound in the projection material P is large in the inert gas (argon). FIG. 12B is a summary of FIG. 12A for each component.

  Therefore, it can be seen from the above that it is good to perform the surface treatment in an inert gas atmosphere in terms of both surface properties and mechanical properties. In addition, the same result is obtained for both argon gas and nitrogen gas as the inert gas.

  On the other hand, what changed the temperature pattern, FIGS. 13-15 has shown the example which changed the time pattern about temperature rising, FPP (shot peening process), and cooling. FIG. 13 shows a pattern for cooling after 10 seconds of temperature rise and 10 seconds of FPP, FIG. 14 shows a pattern for cooling after 10 seconds of temperature rise and 5 seconds of FPP, and FIG. The pattern which performs rapid cooling by injection of an inert gas after 2 seconds is shown.

  The pattern of FIG. 13 and the pattern of FIG. 14 compare the state of the surface with respect to FPP time. FIG. 2 shows FPP for 10 seconds under an argon gas atmosphere, and FIG. 16 shows FPP for 5 seconds under an argon gas atmosphere. 4 shows FPP for 10 seconds in an air atmosphere, and FIG. 17 shows FPP for 5 seconds in an air atmosphere.

  16 is argon-Cr900-FPP for 5 seconds-cooling, FIG. 17 is air-Cr900-FPP for 5 seconds-cooling, FIG. 18 is argon-Cr900-FPP for 10 seconds-rapid cooling, and FIG. 19 is air-Cr900-FPP for 10 seconds- It was processed under the condition of rapid cooling.

  2 and 16, both Cr transfer layer and ferrite layer are observed from the surface side, and when heated in an inert atmosphere, no oxide scale is formed as in the atmosphere. When the projection is performed for a long time, the particle transfer layer becomes thicker. As described above, the Cr transfer layer has improved mechanical performance. However, considering that the ferrite layer has low hardness and needs to be re-quenched, it is preferable that the Cr transfer layer be thin. Therefore, it can be seen that FIG. 16 where the ferrite layer is thin, that is, FPP of 5 seconds is desirable.

  In both FIG. 4 and FIG. 17, an oxide scale layer is observed from the surface side, and the oxide scale layer is thicker in FIG. As described above, the oxide scale layer has poor surface properties and inhibits the transfer of Cr, so that the oxide scale layer is preferably thin. Therefore, it can be seen that FIG. 17 in which the oxide scale layer is thin, that is, FPP of 5 seconds is desirable.

  Next, according to the pattern of FIG. 13 and the pattern of FIG. FIG. 2 shows cooling in an argon gas atmosphere, and FIG. 18 shows rapid cooling in an argon gas atmosphere. FIG. 4 shows cooling in an air atmosphere, and FIG. 17 shows quenching in an air atmosphere.

  In both FIG. 2 and FIG. 18, the Cr layer is observed from the surface side. On the other hand, FIG. 4 shows an oxide scale layer, but FIG. 17 shows no oxide scale layer. This is presumably because the surface oxide scale layer was blown off during the rapid cooling.

  FIG. 20 shows these relationships. Since the surface treatment apparatus 100 improves the mechanical properties of the workpiece W and improves the surface properties, the treatment atmosphere is an inert gas / neutral gas such as argon or nitrogen, and FPP is cooled for a short time. Shows that quenching by gas injection is desirable.

  Next, what changed process temperature T as shown in FIG. 21 is demonstrated. When surface treatment is performed at T = 500 ° C., 700 ° C., and 900 ° C. in the air and an argon gas atmosphere, FIG. 22 shows an observation result with an optical microscope, and FIG. 23 shows an observation result with an electron microscope. .

  As can be seen from FIG. 22, in the atmosphere, the oxide scale thickness increases as the processing temperature increases. On the other hand, in the argon gas atmosphere, the decarburized layer thickness increases (hardness decreases) as the processing temperature increases. As can be seen from FIG. 23, in the air, almost no Cr transfer was observed regardless of the processing temperature, and in the argon gas atmosphere, as the processing temperature increased, the thickness of the Cr transfer layer increased. Yes.

FIG. 24 shows the analysis in the depth direction (XPS analysis) when the surface treatment is performed in an argon gas atmosphere, a treatment temperature of 900 ° C., and a projection time of 10 seconds. The depth direction is shown by the time required for etching. That is, Cr ₂ O ₃ is formed in 0 to 2000 seconds, and a mixed layer of Cr and Fe is formed in 3000 to 6000 seconds. That is, the projection material P exists without chemically bonding to the workpiece W.

  Next, the case where the shot peening time t is changed as shown in FIG. 25 will be described. When surface treatment was performed at t = 10 seconds, 30 seconds, 100 seconds, and 300 seconds in air and argon gas atmosphere, FIG. 26 shows an observation result with an optical microscope, and FIG. 27 shows an observation with an electron microscope. It is a result.

  As can be seen from FIG. 26, an oxide scale is formed in the atmosphere regardless of the particle projection time. It should be noted that in the photograph, the thickness varies due to separation at the time of cutting the cross section. On the other hand, in the argon gas atmosphere, the decarburized layer thickness increases as the particle projection time increases. As can be seen from FIG. 27, in the atmosphere, the transfer of Cr is hardly observed in 30 seconds or less, and a Cr transfer layer is formed by particle projection of 100 seconds or more. On the other hand, in the argon gas atmosphere, as the particle projection time increases, the thickness of the Cr transfer layer increases. In 300 seconds, the surface unevenness becomes remarkable and the thickness becomes non-uniform.

  FIG. 28A is an analysis of the surface texture of the workpiece W. In the atmosphere, almost no Cr element is observed on the surface for 30 seconds or less, and the Cr concentration increases by particle projection for 100 seconds or more. On the other hand, in the argon gas atmosphere, the Cr concentration is saturated in 30 seconds.

  From the above various observations, it can be seen that surface treatment is effective for forming a Cr transfer layer in a short time under an argon gas atmosphere.

FIG. 28B shows the relationship between the potential value E and the chromium concentration on the surface to be processed when dynamic potential polarization measurement is performed and the current density value is 10 mA / cm ² . The potential value E tended to increase as the chromium transfer amount increased, and it was found that chromium present on the surface to be treated contributed to the improvement of corrosion resistance.

  Next, the difference in surface hardness when the cooling method after FPP is changed will be described. That is, FIG. 29 shows the temperature change when the product is allowed to cool after FPP (−0.5 ° C./second). FIG. 30 shows an optical micrograph after processing. FIG. 31 shows a temperature change in the case of air cooling (−7.6 ° C./second) by gas injection after FPP. FIG. 32 shows an optical micrograph after processing. FIG. 33 shows the temperature change in the case of water cooling (−100 ° C./second) after FPP. FIG. 34 shows an optical micrograph after processing.

  When the cooling method is changed in this way, as shown in FIG. 35, a difference occurs in the hardness of each part. That is, it can be seen that the surface hardness is high when water-cooled, and that there is no difference from the case of untreated in other cooling methods. This is probably because decarburization was suppressed by water cooling.

  As described above, according to the surface treatment apparatus 100, the air is replaced with an inert gas / neutral gas, and the projection material P is sprayed onto the workpiece W while the heated state is maintained. By increasing the transfer rate, the mechanical performance can be improved and the generation of oxide scale can be suppressed. Further, after the transfer, by spraying an inert gas / neutral gas onto the workpiece W, the surface deposits can be removed and the surface properties can be enhanced.

  In the above description, S45C is used as the material to be processed W and Cr is used as the projection material P, but other materials may be used.

  The present invention is not limited to the above embodiment. For example, in the above-described example, the object to be processed has a complicated shape having a plurality of irregularities on the surface, such as gears, screws, bolts, nuts, etc., a cylindrical member such as a shaft, and different materials are laminated. Of course, it can also be applied to composite materials and the like. Of course, various modifications can be made without departing from the scope of the present invention.

Explanatory drawing which shows the structure of the surface treatment apparatus which concerns on one embodiment of this invention. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the surface treatment apparatus with the electron microscope (Cr). Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the surface treatment apparatus with the electron microscope (Cr). Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the electron microscope (oxygen). Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the electron microscope (oxygen). Explanatory drawing which shows the mechanism (argon atmosphere) of the transfer in the same surface treatment apparatus. Explanatory drawing which shows the mechanism (atmosphere) of the transfer in the same surface treatment apparatus. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object at the time of changing the temperature conditions in the surface treatment apparatus with the electron microscope (Cr). Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object at the time of changing the temperature conditions in the surface treatment apparatus with the electron microscope (Cr). Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object at the time of changing the temperature conditions in the surface treatment apparatus with the electron microscope (Cr). The graph which shows the hardness of the surface vicinity of the to-be-processed object in the surface treatment apparatus. The graph which shows the component of the surface vicinity of the to-be-processed object in the same surface treatment apparatus. The graph which shows the component of the surface vicinity of the to-be-processed object in the same surface treatment apparatus. The graph which shows an example of the temperature pattern in the same surface treatment apparatus. The graph which shows another example of the temperature pattern in the same surface treatment apparatus. The graph which shows another example of the temperature pattern in the same surface treatment apparatus. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. Explanatory drawing which compares the difference in the surface property by the substitution gas and temperature pattern in the same surface treatment apparatus. The graph which shows the change conditions of the temperature pattern in the same surface treatment apparatus. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the surface treatment apparatus with the electron microscope (Cr). Explanatory drawing which shows the bond energy of the depth direction of the to-be-processed object in the same surface treatment apparatus. The graph which shows the change conditions of the temperature pattern in the same surface treatment apparatus. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the surface treatment apparatus with the electron microscope (Cr). Explanatory drawing which shows the relationship between the injection time in the surface treatment apparatus, and chromium density | concentration. Explanatory drawing which shows the relationship between the electric potential value and chromium concentration in the same surface treatment apparatus. The graph which shows the cooling conditions in the same surface treatment apparatus. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. The graph which shows the cooling conditions in the same surface treatment apparatus. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. The graph which shows the cooling conditions in the same surface treatment apparatus. Explanatory drawing which looked at the cross section of the surface vicinity of the to-be-processed object in the same surface treatment apparatus with the optical microscope. Explanatory drawing which shows the hardness of each part of the to-be-processed object by the difference in the cooling system in the same surface treatment apparatus.

  DESCRIPTION OF SYMBOLS 100 ... Surface treatment apparatus, 110 ... Chamber, 111 ... Exhaust port, 112 ... Oxygen meter, 120 ... Support stand, 121 ... Temperature sensor, 130 ... Induction heating coil, 140 ... Injection nozzle, 142 ... Electromagnetic valve, 150 ... Particle Feeder, 151 ... Feeder line, 152-154 ... Particle feeder adjustment valve, 160 ... Gas cylinder, 161 ... Flow valve / pressure adjustment valve, 170 ... Water cooling mechanism (cooling unit), 200 ... High frequency application device, 300 ... Control unit, W ... Subject, P ... Projection material.

Claims (8)

In a surface treatment apparatus that performs surface treatment by spraying a projection material onto a workpiece,
A chamber;
An inert gas introduction section for introducing an inert gas into the chamber;
A support part disposed in the chamber and supporting the object to be processed;
An induction heating coil that is disposed around the support and heats the workpiece;
A high-frequency application unit for induction-heating the workpiece by supplying a high-frequency current to the induction heating coil;
A projection material injection unit that injects the projection material together with the inert gas toward the support unit;
A cooling unit for cooling the object to be processed;
An inert gas is introduced from the inert gas introduction unit to replace the inside of the chamber with the inert gas, and a high-frequency current is supplied from the high-frequency application unit to the induction heating coil so that the object to be processed has a predetermined temperature. After the object to be processed is heated to a predetermined temperature, the projection material and the inert gas are injected from the projection material injection unit, and the object to be processed is maintained at the predetermined temperature. A surface treatment apparatus comprising: a control unit that supplies a high-frequency current to the induction heating coil and cools the workpiece by the cooling unit. The cooling unit includes an inert gas injection unit configured to inject and cool the inert gas toward the support unit,
The surface treatment apparatus according to claim 1, wherein the control unit further cools the object to be treated by injecting only an inert gas from the inert gas injection unit.   The surface treatment apparatus according to claim 1, wherein the cooling unit is configured to inject a cooling liquid toward the support unit. In the surface treatment method of spraying a projection material onto a workpiece to be treated contained in a chamber and performing a surface treatment,
A replacement step of replacing the inside of the chamber with an inert gas;
A heating step of heating the workpiece to a predetermined processing temperature;
Projecting the projection material toward the object to be processed in the predetermined temperature range, and transferring to the surface of the object to be processed; and
And a cooling step of rapidly cooling the object to be treated by spraying an inert gas. In a surface treatment apparatus that performs surface treatment by spraying a projection material onto a workpiece,
A chamber;
A neutral gas introduction part for introducing a neutral gas into the chamber;
A support part disposed in the chamber and supporting the object to be processed;
An induction heating coil that is disposed around the support and heats the workpiece;
A high-frequency application unit for induction-heating the workpiece by supplying a high-frequency current to the induction heating coil;
A projection material injection unit that injects the projection material together with the neutral gas toward the support unit;
A cooling unit for cooling the object to be processed;
A neutral gas is introduced from the neutral gas introduction part to replace the inside of the chamber with the neutral gas, and a high-frequency current is supplied from the high-frequency application part to the induction heating coil to bring the object to be processed to a predetermined temperature. And after the workpiece is heated to a predetermined temperature, the projection material and the neutral gas are injected from the projection material injection unit and the workpiece is maintained at the predetermined temperature. A surface treatment apparatus comprising: a control unit that supplies a high-frequency current to the induction heating coil and cools the workpiece by the cooling unit. The cooling unit includes a neutral gas injection unit configured to inject and cool the neutral gas toward the support unit,
The surface treatment apparatus according to claim 5, wherein the control unit further cools the workpiece by injecting only the neutral gas from the neutral gas injection unit. In the surface treatment method of spraying a projection material onto a workpiece to be treated contained in a chamber and performing a surface treatment,
A replacement step of replacing the inside of the chamber with a neutral gas;
A heating step of heating the workpiece to a predetermined processing temperature;
Projecting the projection material toward the object to be processed in the predetermined temperature range, and transferring to the surface of the object to be processed; and
A surface treatment method comprising: a cooling step of rapidly cooling the object to be treated by spraying a neutral gas. In the surface treatment method of spraying a projection material onto a workpiece to be treated contained in a chamber and performing a surface treatment,
A replacement step of replacing the inside of the chamber with an inert gas or a neutral gas;
A heating step of heating the workpiece to a predetermined processing temperature;
Projecting the projection material toward the object to be processed in the predetermined temperature range, and transferring to the surface of the object to be processed; and
And a cooling step of rapidly cooling the object to be processed by spraying a cooling liquid.

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