KR101910467B1 - Surface treatment method using local heating and ultrasonic nanocrystal surface modification - Google Patents
Surface treatment method using local heating and ultrasonic nanocrystal surface modification Download PDFInfo
- Publication number
- KR101910467B1 KR101910467B1 KR1020160150570A KR20160150570A KR101910467B1 KR 101910467 B1 KR101910467 B1 KR 101910467B1 KR 1020160150570 A KR1020160150570 A KR 1020160150570A KR 20160150570 A KR20160150570 A KR 20160150570A KR 101910467 B1 KR101910467 B1 KR 101910467B1
- Authority
- KR
- South Korea
- Prior art keywords
- local heating
- unsm
- surface modification
- unit
- surface treatment
- Prior art date
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D10/00—Modifying the physical properties by methods other than heat treatment or deformation
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F3/00—Changing the physical structure of non-ferrous metals or alloys by special physical methods, e.g. treatment with neutrons
- C22F3/02—Changing the physical structure of non-ferrous metals or alloys by special physical methods, e.g. treatment with neutrons by solidifying a melt controlled by supersonic waves or electric or magnetic fields
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2201/00—Treatment for obtaining particular effects
- C21D2201/03—Amorphous or microcrystalline structure
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2221/00—Treating localised areas of an article
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment method for improving strength by performing heat treatment only on parts required for use of large parts such as crankshafts of large diesel engines, large gears, bearings and dies, There has been a problem in that there is a limitation in the method for improving the hardness and the post-treatment of changing the tensile residual stress on the surface to the compressive residual stress and for improving the surface of the object to give better mechanical characteristics. In order to solve the problems of the conventional surface treatment methods using the technique, through the fusion of the local heating technique and the ultrasonic nanocrystal surface modification (UNSM) technology, It is structured to handle the surface treatment process There is provided a surface treatment method using local heating and ultrasonic nanocrystal surface modification, which is configured to improve both the mechanical properties, performance and lifetime of the object.
Description
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment and a surface treatment method for treating surfaces of machine parts and mold tools, and more particularly, to a heat treatment and a surface treatment method for machining surfaces of large parts such as crankshafts, large gears, bearings, The surface hardness is increased by increasing the surface hardness, the fatigue strength is increased, and the fatigue strength is increased and the wear rate is decreased by forming the compressive residual stress. , It can be replaced by conventional surface hardening technology which forms high hardness phase, crystal grains and residual stress by cooling at a proper speed after heating and mechanical characteristic formation which is lower than the wear rate improvement level required in conventional surface hardening heat treatment In order to solve the problem of the difficult conventional UNSM technology, the heating phase used in the conventional heat treatment The carbon or nitrogen element is moved from the inside to the surface layer, the microstructure is changed, the crystal grains are made fine, and the compression residual And more particularly, to a surface treatment method using local heating and ultrasonic nanocrystal surface modification, which is configured so as to improve mechanical performance and lifetime while imparting better mechanical properties to the conventional method by adding stress.
In order to improve the strength by heat-treating only the parts required for the design of the large-sized parts and the mold as described above, the local heating technique and the ultrasonic nanocrystal surface modification (UNSM) (UNSM) to improve the surface of the object and recover the fatigue strength due to heating, by performing local heating on the part required for the design of the object by improving the strength of the object, And a surface treatment method using local heating and ultrasound nano-crystal surface modification, which is configured to improve both the mechanical performance and strength, characteristics and lifetime of the object.
Generally, for example, in the production of mold tools such as bearings, gears, shafts, turbines, and the like, and mold tools such as press molds, steel industry, paper, and rolls in the semiconductor display industry, , Various heat treatment and surface treatment techniques are applied in order to improve the mechanical characteristics of the processed product or add other features.
That is, the surface treatment refers to various treatments that are carried out to impart corrosion resistance, abrasion resistance, heat resistance and appearance to the surfaces of metals and nonmetals. As the kinds of the treatments, (Chemical Coatings), which performs a chemical treatment that forms a kind of chemical coating (such as a phosphate coating) on the surface of a metal, and a chemical treatment that electrochemically forms an oxide coating with a metal object as an anode A bipolar coating, a painting which paints the surface of the metal for the purpose of preventing corrosion and aesthetics, a lining which covers the inner surface of the tank made of metal such as rubber and synthetic resin, And surface hardening treatment (process of hardening the surface by impregnating carbon or nitrogen or the like to improve physical properties).
More specifically, examples of the plating method include electroplating, chemical plating, hot-dip plating, vacuum plating, penetration plating, and ion plating. Examples of the chemical conversion treatment include a phosphate coating treatment, a chromate treatment, And the bipolar coating process is widely used for an oxide film of aluminum, and typical surface hardening processes include heat treatment of metal.
That is, the heat treatment technique of the metal is performed by repeating the heating and cooling in the middle or the final stage of the manufacturing process in order to change the mechanical properties of the metal material, the mechanical parts and the mold tool to impart properties such as abrasion resistance, impact resistance, Techniques can be broadly divided into two types: a technique of improving the mechanical and physical performance by making the material hard, and a technique of improving the workability by making the material soft.
Further, in the above-described heat treatment technique, when the size of the crankshaft of the large diesel engine, large gears, bearings, etc., is large and the heat treatment for the whole is not easy, A local heating technique for improving the strength by performing heat treatment only on a necessary portion is widely used.
Here, examples of the conventional techniques for the local heating method as described above include, for example, a method of forming and processing a high-strength magnesium plate through a local softening process by rapid heating, According to the present invention, there is provided a method of manufacturing a high-strength magnesium plate material, comprising the steps of: locally softening a portion of a high-strength magnesium plate material (H-temper) requiring heat treatment to increase local elongation; , It is possible to increase the elongation rate selectively by selectively locally heating only the parts that need to be formed. In the region where high strength is required because machining is not required, only the heating without heating or the minimum heating is performed, A method of forming and processing a magnesium plate through a local softening process which can be maintained, This technique has been suggested about the magnesium sheet molded by a processing method.
In addition, according to another example of the conventional technique for the local heating method as described above, for example, Korean Patent Registration No. 10-1383393 discloses a method of simultaneously performing cold forming and hot stamping, A local hot stamping forming apparatus capable of manufacturing a component having strength and a hot stamping forming method using the same.
Further, as another example of the conventional technique for the local heating method as described above, for example, according to Korean Patent Registration No. 10-1354149, there is proposed a method of heating a steel plate, such as high tensile steel, aluminum alloy, magnesium alloy, titanium alloy, To improve the formability of the material, it is possible to perform selective heating only in a local region where plastic deformation of the material occurs without designing and manufacturing a separate heat source, A technical content of a local heating plate material forming apparatus having a frame has been proposed.
Further, as another example of the conventional technique for the local heating method as described above, for example, Korean Patent Publication No. 10-1235752 discloses a method of locally heating, bending or twisting molding and cooling repeatedly / continuously And a method of bending and twisting molding using local heating and gradual forming capable of bending in various directions of the material can be achieved.
As described above, in recent years, a local heating technique has been widely used in which heat treatment is performed only on necessary parts in various fields. However, the conventional local heating method as described above has the following problems.
More specifically, the conventional heat treatment method by local heating is basically a method of improving the strength of the metal surface by heating after being heated at a high temperature. Therefore, The tensile residual stress is generated on the peripheral surface of the object after the heat treatment and the fatigue strength is lowered. To this end, the conventional heat treatment method by local heating is a post-process in which a surface such as shot peening, deep rolling It has been difficult to recover the tensile residual stress of the large object or to change the residual stress to the compressive residual stress, There is a problem in that it takes a lot of cost to perform post-treatment such as heat treatment and pinning.
That is, the conventional heat treatment by local heating requires additional additional equipment and processes for the surface treatment process after the local heating process as described above, thereby complicating the manufacturing process and increasing the time and cost In order to solve this problem, it is desirable to provide a new local heating and surface treatment technology capable of treating local heating and surface treatment processes in a continuous process in the same equipment. There have been no suggestions for devices or methods.
Therefore, as described above, no post-treatment for changing the tensile residual stress formed on the surface of the object after the heat treatment to the compressive residual stress is taken into consideration at all. In addition, the heat treatment using the local heating and the separate surface treatment method are separately performed In order to solve the problems of the prior art, which is limited in process shortening and cost reduction in that it must be carried out with the process, it is necessary not only to improve the strength of the object by performing surface modification at the time of heat treatment such as local heating It is desirable to provide a surface treatment method of a new constitution which is configured to remove defects on the surface caused by heat treatment and to restore cumulative fatigue to give better mechanical properties. However, The method is not presented.
[Prior Art Literature]
1. Korean Registered Patent No. 10-1427293 (July 31, 2014)
2. Korean Patent Registration No. 10-1383393 (Apr.
3. Korean Patent Registration No. 10-1354149 (Apr. 15, 2014).
4. Korean Patent Registration No. 10-1235752 (Feb.
5. "Characterization and Application of Ultrasonic Nano-Surface Modification Technology", Yong-Sik Yi, Jung-Hyun Park, In-Ho Cho, Chang-Sik Kim, Chang Min Kim, Transactions of the Korean Society of Mechanical Engineers, Vol. 190 ~ 195, 2009.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a large-sized diesel engine which is capable of producing large-sized components such as crankshafts, large gears, bearings and molds of a large- There is no consideration of the post-treatment which changes the tensile residual stress on the surface to the compressive residual stress. In addition, there is no limitation on the method for modifying the surface of the object and imparting better mechanical properties to the hardness, (USSM) technology to solve the problems of the conventional surface treatment methods using conventional heat treatment and local heating techniques, the local heating technique and the ultrasonic nano-crystal surface modification (UNSM) By being configured to process the heating and surface treatment processes, Heat is applied to improve the mechanical strength, and ultrasonic nano-crystal surface modification (UNSM) is performed to remove defects on the surface caused by heat treatment and to change tensile residual stress to compressive residual stress to give better mechanical characteristics And a method for surface treatment using local heating and ultrasonic nano-crystal surface modification.
Another object of the present invention is to provide a method and apparatus for processing local heating and surface treatment processes in a continuous process in the same equipment through fusion of local heating technology and ultrasonic nanocrystal surface modification (UNSM) Which is configured to improve the mechanical properties, performance and lifetime of the object in a short time at a low cost in the manufacture of large parts such as crankshafts of large diesel engines, large gears, bearings and molds, And to provide a surface treatment method using crystal surface modification.
In order to accomplish the above object, according to the present invention, there is a need for additional equipment and process for the post-treatment for changing the tensile residual stress formed on the surface of the object after heat treatment to the compressive residual stress and for the surface treatment process after heat treatment. Which is disadvantageous in that the manufacturing process is cumbersome and time and cost is increased due to the local heating and the surface treatment process in the same equipment, A surface treatment method using ultrasonic nano-crystal surface modification, comprising: preparing an object to be surface-treated; Performing a local heating process to impart the desired mechanical characteristics to the object prepared in the step of preparing the object; Performing ultrasonic nanocrystal surface modification (UNSM) on the surface of the object subjected to local heating in the step of performing the local heating process; And performing a finishing operation including a finishing process on the object whose surface has been modified in the step of performing the ultrasonic nano-crystal surface modification (UNSM). A surface treatment method using a modification is provided.
Here, the step of preparing the object is characterized in that processing for machining a metal product or a mechanical part including a bearing, a gear, a mold or a shaft into a desired size and shape is performed.
Also, the step of performing the local heating process is characterized in that a process for realizing a desired mechanical strength is performed by performing a heat treatment on a necessary position in design of the object.
In addition, the step of performing the finishing operation may include performing a finishing process including painting and surface treatment on the object on which the local heating and the ultrasonic nano-crystal surface modification have been performed, thereby completing the final product .
Further, the surface treatment method is characterized in that, in the step of performing the local heating treatment, the entire heating treatment is performed instead of the local heating treatment.
According to the present invention, there is also provided a surface treatment apparatus configured to perform a surface treatment method using the above-described local heating and ultrasonic nano-crystal surface modification, comprising: a jig for fixing an object; Conveying means capable of conveying the object mounted on the jig; A heating unit for performing local heating on the object mounted on the jig; And a surface modifying unit for performing ultrasonic nanocrystal surface modification (UNSM) on the object mounted on the jig.
Here, the surface treatment apparatus is characterized in that the heating section and the surface modifying section are arranged at a predetermined fixed interval or in a line, the object is mounted on the jig and the local heating process is performed, And performing the ultrasonic nanocrystal surface modification (UNSM) by transferring the object mounted on the jig to the surface modification part.
In addition, the surface treatment apparatus may further include a cooling unit including a cooler provided between the heating unit and the surface modification unit, so that after the local heating process is performed, And the object can be cooled while the object is being transferred to the surface modification unit.
Further, the surface treatment apparatus is configured such that the heating unit and the surface modification unit are movable by the conveying unit while the object is fixed, so that after performing the local heating process at a desired position through the heating unit, (UNSM) by continuously moving the surface modifying part to the corresponding position by the ultrasonic wave modifying part, so that it can be easily applied to a large-scale heat-treating operation.
As described above, according to the present invention, it is possible to perform local heating and surface treatment processes in a continuous process in the same equipment through fusion of local heating technology and ultrasonic nanocrystal surface modification (UNSM) (UNSM) is performed to remove defects on the surface during heat treatment, and the tensile residual stress is changed to the compressive residual stress to improve the mechanical strength The surface treatment method using the local heating and the ultrasonic nano-crystal surface modification configured to impart the characteristics of the large-sized diesel engine can be realized at a low cost in a short time in manufacturing large parts such as crank shafts, large gears, bearings, Easily improve both the mechanical properties, performance and lifetime of the object. There.
Further, according to the present invention, by processing the local heating and the surface treatment process in a continuous process in the same equipment through the fusion of the local heating technology and the ultrasonic nano-crystal surface modification (UNSM) technology as described above, By providing a surface treatment method using local heating and ultrasonic nano-crystal surface modification, which is configured to give better mechanical properties to large parts such as crankshafts of engines, large gears, bearings and molds, There is no consideration of the post-treatment which changes the tensile residual stress to be formed into the compressive residual stress and the method of modifying the surface of the object to improve the hardness and giving better mechanical characteristics Conventional surfaces using conventional heat treatment and local heating techniques It can solve the problem of how Lee.
1 is a diagram schematically showing the overall structure of a surface treatment method using local heating and ultrasonic nano-crystal surface modification according to an embodiment of the present invention.
2 is a view showing an example of a nano-skin formed of UNSM.
FIG. 3 is a schematic view showing a state in which a halogen lamp is installed in a UNSM apparatus according to a surface treatment method using local heating and ultrasonic nano-crystal surface modification according to an embodiment of the present invention and heat treatment is performed.
4 is a view showing a result of a verification test for verifying the effect of a surface treatment method using local heating and ultrasonic nano-crystal surface modification according to an embodiment of the present invention.
5 is a view illustrating a result of a verification test for verifying the effect of a surface treatment method using local heating and ultrasonic nano-crystal surface modification according to an embodiment of the present invention.
6 is a view showing a result of a verification experiment for verifying the effect of a surface treatment method using local heating and ultrasonic nano-crystal surface modification according to an embodiment of the present invention.
7 is a view showing a result of a verification experiment for verifying the effect of a surface treatment method using local heating and ultrasonic nano-crystal surface modification according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, with reference to the accompanying drawings, a specific embodiment of a surface treatment method using local heating and ultrasonic nanocrystal surface modification according to the present invention will be described.
Hereinafter, it is to be noted that the following description is only an embodiment for carrying out the present invention, and the present invention is not limited to the contents of the embodiments described below.
In the following description of the embodiments of the present invention, parts that are the same as or similar to those of the prior art, or which can be easily understood and practiced by a person skilled in the art, It is important to bear in mind that we omit.
That is, the present invention relates to a method for manufacturing a large-sized component such as a crankshaft of a large-sized diesel engine, a large gear, a bearing, a mold, and the like, which changes the tensile residual stress formed on the surface of the object after heat treatment, In addition to the fact that post-treatment is not taken into account at all, there has been a limit in not improving the hardness and improving the surface of the object to give better mechanical properties. In order to solve the problems of the surface treatment methods, the local heating and the surface treatment process can be processed in a continuous process in the same equipment through the fusion of the local heating technique and the ultrasonic nano crystal surface modification (UNSM) Local heating is applied to the object to improve the mechanical strength, and ultrasound nano- Surface heating (UNSM) to remove surface defects during heat treatment, and to change the tensile residual stress to compressive residual stress to provide better mechanical properties. The present invention relates to a surface treatment method using a metal surface.
In addition, the present invention is configured to process local heating and surface treatment processes in a continuous process in the same equipment through fusion of local heating technology and ultrasonic nanocrystal surface modification (UNSM) technology, Localized heating and ultrasonic nano-crystal surfaces, which are designed to improve both the mechanical properties, performance and lifetime of objects in a short time at low cost in manufacturing large parts such as crankshafts of large diesel engines, large gears, bearings and molds The present invention relates to a surface treatment method using a surface modification method.
That is, the conventional surface hardening technique is carried out for the purpose of reducing the wear rate by increasing the surface hardness, raising the fatigue strength, reducing the wear rate and increasing the fatigue strength by forming the residual compressive stress, and for example, In the case of a steel using a curve, the steel is cooled at a proper speed after heating at a temperature of 900 degrees or more, which is a temperature higher than the austenite phase change, to form a high hardness phase, crystal grains, residual stress, , And the conventional UNSM technique is difficult to replace with the mechanical property formation which is lower than the level of the wear rate improvement required in the conventional surface hardening heat treatment.
Thus, in the present invention, as described later, by applying the extreme elasto-plastic strain energy at all or by local heating in an appropriate heating state at a room temperature or lower than the heating state used in the conventional heat treatment, an element such as carbon or nitrogen Is transferred from the inside to the surface layer, the microstructure is changed, the crystal grain is made fine, and the compressive residual stress is added.
Next, with reference to the drawings, the details of the surface treatment method using the local heating and ultrasonic nano-crystal surface modification according to the present invention will be described.
Referring to FIG. 1, FIG. 1 is a view schematically showing the overall structure of a surface treatment method using local heating and ultrasonic nano-crystal surface modification according to an embodiment of the present invention.
As shown in FIG. 1, the method for surface treatment using local heating and ultrasonic nano-crystal surface modification according to the embodiment of the present invention roughly comprises the steps of preparing an object to be surface-treated (S10) A step (S20) of performing a local heating process to give a desired mechanical property to a required part of the prepared object, and a step (S20) of removing the defect on the surface of the object subjected to the local heating process and modifying the surface of the object (UNSM) which improves mechanical properties (such as strength, hardness, surface roughness, texture density and crystal grain size) and adds compressive residual stress by changing tensile residual stress to compressive residual stress In operation S30, a finishing operation such as a finishing operation is performed on the surface-modified object in operation S40. It can comprise.
Here, the step S10 of preparing the object may be performed by, for example, machining a metal product or a mechanical part, such as a bearing, a gear, a mold, or a shaft, into a desired size and shape to perform local heating and ultrasonic nano- And a process of attaching to a surface treatment apparatus for carrying out the present invention may be performed.
The step (S20) of performing the above-mentioned local heating process may be a step in which a process for implementing a desired mechanical strength is performed by performing heat treatment only on a part of the object mounted on the surface treatment apparatus, have.
At this time, as described above, in the local heating process, tensile residual stress is generated on the surface of the object due to the characteristic of the heat treatment process proceeding at a high temperature, and in some cases, defects such as scratches may occur on the surface.
Here, this problem can be improved by applying ultrasonic nanocrystal surface modification (UNSM) technology to metal products or mechanical parts such as bearings, gears, molds, shafts, etc., have.
Accordingly, in order to solve the problems that may occur in the above-described local heating process, the present invention is configured to improve the mechanical properties while preventing the occurrence of defects by modifying the surface of the object after the heat treatment.
More specifically, the UNSM treatment is performed by attaching a tool (tungsten carbide ball / cermet ball or spherical shape tool) of 1 to several tens mm diameter to an ultrasonic device, The forces are combined such that the balls strike the surface of the specimen to 40,000 per second and up to 100,000 per mm 2 .
These impacts can be considered as micro-cold-forging and cause plastic and elastic deformation in the surface layer, leading to deep residual stress and nanocrystalline structure In addition, it produces numerous, non-uniform micro-dimples on the surface of the specimen and improves surface properties.
In addition, according to the Hal-Petch relationship, the nanostructure modification of the surface layer simultaneously improves the strength (hardness) and ductility (toughness) of the specimen It is already well known.
That is, generally, in a bearing or the like, a rotary-bending fatigue (RBF) and a rolling contact fatigue (RCF) It is possible to recover and improve the fatigue surface, thereby extending the service life of the parts. [0052] [49] As described above, when the UNSM technique is applied to general engineering bearing steels (Japanese standard SUJ2 and SUJ3) Thereby reducing the cost of part replacement and maintenance.
Therefore, as described above, by forming the nanoskin by applying the ultrasonic nanocrystal surface modification (UNSM) technique, the surface of the component can be modified, the cumulative fatigue can be restored, and the service life can be prolonged have.
More specifically, referring to FIG. 2, FIG. 2 is a view showing a configuration example of a nano-skin formed of UNSM.
Namely, as shown in Fig. 2, the nanoskin surface layer is composed of nano-sized surface roughness and texturing texture, and the depth of the subcutaneous layer is from ~ , A gradient structure in which the hardness increases from the depth of ~ 1,500 탆 to the surface layer and the residual stress is increased from the depth of ~ 2,000 탆 to the surface layer and the residual stress value of the surface layer is 1 Giga Pascal A skin structure with a larger structure is called a nano-skin.
Here, the details of the above-described ultrasonic nanocrystal surface modification (UNSM) technology can be found in, for example, the literature of the prior art such as "Study on characteristics and utilization of ultrasound nano-surface modification technology " (See prior art document 5).
That is, the step (S30) of performing the ultrasonic nano-crystal surface modification (UNSM) described above may be performed by applying the ultrasonic nano-crystal surface modification (UNSM) technique to the object subjected to the local heating process as described above By forming a nanoskin on the surface of the object, it is possible to remove the defects present on the surface, texturing it to improve the mechanical properties, recover cumulative fatigue due to the high temperature in the heat treatment process, Can be further improved.
The step of performing the finishing operation S40 is a step of finishing the object subjected to the local heating and the ultrasonic nano-crystal surface modification as described above, such as painting or surface treatment, to complete the final product Lt; / RTI >
Here, although not shown, the surface treatment apparatus for performing the surface treatment method using the local heating and ultrasonic nanocrystal surface modification according to the present invention configured as described above may be used, for example, A heating section, a surface modifying section for performing ultrasonic nanocrystal surface modification (UNSM), and conveying means such as a conveyor belt capable of conveying an object mounted on a jig and a jig for fixing an object have.
More particularly, the surface treatment apparatus for performing the surface treatment method using the local heating and the ultrasonic nano-crystal surface modification according to the present invention is characterized in that the heating unit and the surface modification unit are arranged at regular intervals, And then performing a local heating process on a necessary portion by mounting an object on the jig, and then transferring the heat-treated portion through the transfer means to the surface modification portion to perform ultrasonic nano-crystal surface modification (UNSM) A cooling means such as a cooler may be installed between the part and the surface modification part so as to cool the heat of the object during transportation.
Alternatively, the above-mentioned surface treatment apparatus is configured so that the heating unit and the surface modification unit can be moved by the conveying means while the object is fixed, for example, when the object is a large-sized component, (UNSM) is continuously performed by moving the surface modification part to a corresponding position by a transferring device after performing a local heating process at a desired position through a part of the substrate, and thus it can be easily applied to a large scale heat treatment work.
In addition, in the embodiment of the present invention described above, the present invention is explained by exemplifying the case where the heat treatment is performed only in a necessary portion in the step (S20) of performing the local heating process, but the present invention is not limited thereto That is, the present invention may be variously configured as necessary, such that the entire heating process for heating the entire object in place of the local heating described above may be performed.
Next, with reference to FIG. 3 to FIG. 7, a verification experiment for verifying the actual performance and effect of the surface treatment method using the local heating and ultrasonic nano-crystal surface modification according to the embodiment of the present invention constructed as described above The results will be described.
Referring to FIG. 3, FIG. 3A is a view schematically showing a halogen lamp installed in an UNSM apparatus according to a surface treatment method using local heating and ultrasonic nano-crystal surface modification according to an embodiment of the present invention. 3B is a view showing a state in which heat treatment is performed using a halogen lamp.
4 to 7, in order to verify the effect of the surface treatment method using the local heating and ultrasonic nano-crystal surface modification according to the embodiment of the present invention, Respectively.
More specifically, referring first to FIG. 4, FIG. 4 is a graph comparing the temperature of a specimen (H / T) thermally treated and a specimen (H / T + UNSM) subjected to heat treatment and UNSM treatment on a Ti- And the surface roughness according to the present invention.
4, the surface roughness (Ra) of the specimen (H / T) heat-treated at temperatures of 600 ° C, 800 ° C and 1000 ° C, while the surface roughness Ra of the general untreated specimen is Ra = 0.52 (H / T + UNSM) were 0.393, 0.216 and 0.122 (㎛), respectively, and the surface roughness of the heat treated and UNSM treated specimens (H / T + UNSM) were improved to 0.325, 0.185 and 0.102 (㎛), respectively.
5, FIG. 5 is a graph showing the surface hardness (H / T) of the Ti-6Al-4V alloy specimen subjected to the heat treatment and the heat treatment and the UNSM treated specimen hardness "). < / RTI >
As shown in FIG. 5, the surface hardness of the general untreated specimen was 338 HV, while the surface hardness of the specimen (H / T) heat treated at 600 ° C., 800 ° C. and 1000 ° C. was 514, 553 and 700 HV), and the surface hardness of the heat treated and UNSM treated specimens (H / T + UNSM) were improved to 629, 903, and 933 (HV), respectively.
Referring to FIG. 6, FIG. 6 is a view showing a result of comparing friction coefficients of the untreated, general UNSM, localized heat, and UNSM treated specimens.
In FIG. 6, S1 is a non-treated specimen, S1 UNSM is a specimen subjected to a general UNSM treatment, S2 is a specimen subjected to a local heat treatment at 600 DEG C, S2 UNSM is a specimen subjected to a local heat treatment (600 DEG C) (400 ° C) + UNSM treated specimens were subjected to local heat treatment (800 ° C) + UNSM treated specimens, while S4 was locally heat treated specimens at 1000 ° C. Respectively.
6, the friction coefficient of the untreated specimen S1 was 0.78, the coefficient of friction of the ordinary UNSM-treated specimen S1 UNSM was 0.73, and the specimens subjected to the local heat treatment at 600 ° C, 800 ° C and 1000 ° C The coefficients of friction of the specimens subjected to local heat treatment and UNSM treatment (S2 UNSM, S3 UNSM and S4 UNSM) were 0.68, 0.66 and 0.64, respectively, It can be seen that the friction coefficient of the specimens subjected to the local heat treatment and UNSM treatment is the lowest compared to the case where only heat treatment or UNSM is performed.
Further, referring to FIG. 7, FIG. 6 is a diagram showing the results of comparing the wear rate of the untreated, general UNSM, localized, heat treated, and UNSM treated specimens.
In FIG. 7, S1 is a non-treated specimen, S1 UNSM is a specimen subjected to general UNSM treatment, S2 is a specimen subjected to a local heat treatment at 600 DEG C, S2 UNSM is a specimen subjected to a local heat treatment (600 DEG C) (400 ° C) + UNSM treated specimens were subjected to local heat treatment (800 ° C) + UNSM treated specimens, while S4 was locally heat treated specimens at 1000 ° C. Respectively.
7, the abrasion rate of the untreated specimen S1 was 137, the abrasion rate of the ordinary UNSM-treated specimen S1 (UNSM) was 82, and the specimens subjected to the locally heat treatment at 600, 800, The abrasion rates of S1, S2, S3 and S4 were 134, 7.8 and 7.4, respectively, while the wear rates of S2, UNSM, S3 UNSM and S4 UNSM were 74, 2.2 and 1.8, respectively. The local heat treatment and UNSM The wear rate of the specimens subjected to the local heat treatment and UNSM treatment was also lowest.
Therefore, it has been found from the above-mentioned experimental results that when the surface roughness of the metal is reduced and the surface hardness is increased after the local heating, the friction / wear characteristics are improved and the tensile residual stress formed on the surface of the metal is changed to the compressive residual stress, Can be improved.
Further, as shown in the above embodiments of the present invention, it can be seen that when the local heating technique and the ultrasonic nano-surface reforming (UNSM) technique are used at the same time, the properties improved by local heating are further improved. For example, The surface roughness is further reduced, the surface hardness is further increased, and the friction / wear characteristics are further improved when UNSM is applied after heating.
4 to 7, when the local heating technique and the ultrasonic nano-surface modification technique are applied together, the surface roughness Ra decreases from 0.52 m to 0.22 m and the surface hardness increases from 514 HV to 629 HV , the coefficient of friction is reduced, and the wear resistance is improved to 137 × 10 -6 mm 3 / Nm → 82 × 10 -6 mm 3 / Nm, compressive residual stress is increased to 100 MPa -1000 MPa to 0.78 → 0.64 →, It can be confirmed that the particle size is improved from 100 탆 to 50 탆.
Therefore, as can be seen from the above experimental results, the conventional UNSM technology has only a limited improvement in mechanical characteristics, which is less than the level of improvement in wear rate required in the conventional surface hardening heat treatment. However, Is a technique for moving an element such as carbon or nitrogen from the inside to the surface layer to change the microstructure and to refine the crystal grain to add compressive residual stress. By adding extreme elasto-elastic strain energy at low temperatures, the effect of surface hardness increase, wear resistance reduction and fatigue strength increase can be remarkably improved.
Although the present invention has been described with respect to specific embodiments of the surface treatment method using the local heating and ultrasonic nanocrystal surface modification according to the present invention as described above, That is, for example, in the step of performing the local heating process (S20), the entire heating process for heating the entire object may be performed instead of the local heating process for heat-treating a part of the object, It should be noted that the present invention can be configured in various forms as needed.
Therefore, the surface treatment method using the local heating and ultrasonic nanocrystal surface modification according to the present invention can be implemented as described above.
According to the present invention, by using the local heating method and the ultrasonic nano-crystal surface modification according to the present invention as described above, Through the fusion of crystal surface modification (UNSM) technology, the local heating and surface treatment process is processed in a continuous process in the same equipment to perform local heat treatment on the object to improve the mechanical strength, and the ultrasonic nano crystal surface modification (UNSM) to remove surface defects during heat treatment, and to change the tensile residual stress to compressive residual stress to provide better mechanical properties. Surface treatment using local heating and ultrasonic nano-crystal surface modification The crankshaft of the large diesel engine, the large gear, At a lower cost in the production of large components, such as the ring and the mold can be easily improved both the mechanical properties and the performance and life of the object in a short time.
In addition, according to the present invention, by processing the local heating and the surface treatment process in a continuous process in the same equipment through the fusion of the local heating technology and the ultrasonic nanocrystal surface modification (UNSM) technology as described above, By providing a surface treatment method using local heating and ultrasonic nano-crystal surface modification, which is configured to give better mechanical properties to large parts such as crankshafts of engines, large gears, bearings and molds, There is no consideration of the post-treatment which changes the tensile residual stress to be formed into the compressive residual stress and the method of modifying the surface of the object to improve the hardness and giving better mechanical characteristics Conventional tables using conventional heat treatment and local heating techniques It can solve the problem of how to handle.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be understood that the present invention is not limited thereto. It will be understood by those skilled in the art that various changes, modifications, combinations, and substitutions may be made without departing from the scope of the present invention as set forth in the following claims. I will.
Claims (9)
Preparing an object to be surface-treated;
Performing a local heating process only on a part of the object prepared in the step of preparing the object necessary for use function;
Performing ultrasonic nanocrystal surface modification (UNSM) on the surface of the object subjected to local heating in the step of performing the local heating process; And
Performing a finishing operation including a finishing process on the object having the surface modified in the step of performing the ultrasonic nano-crystal surface modification (UNSM)
In the surface treatment method,
A heating unit for performing a local heating process on the object mounted on the jig and a heating unit for heating the object mounted on the jig, And a surface modifying unit for performing an ultrasonic nano-crystal surface modification (UNSM) on the substrate, wherein the object is mounted on the jig and transferred to the heating unit through the transfer unit to perform a local heating process (UNSM) to the surface modifying unit through the transferring unit, performing the local heating process, and performing the ultrasonic nano-crystal surface modification (UNSM) And is configured to be able to be processed in a continuous process in the same equipment. Surface treatment method using the wave nanocrystal surface modification.
Wherein preparing the object comprises:
A method for surface treatment using local heating and ultrasonic nano-crystal surface modification, characterized in that a process for machining a metal product or machine part including a bearing, a gear, a mold or a shaft into a desired size and shape is carried out.
The step of performing the finishing operation includes:
And performing a finishing treatment including painting or surface treatment on the object on which the local heating and the ultrasonic nano-crystal surface modification have been performed to complete the final product. .
In the surface treatment method,
Wherein the step of performing the local heating process is configured to perform a total heating process in place of the local heating process.
A jig for fixing the object;
Conveying means capable of conveying the object mounted on the jig;
A heating unit for performing a local heating process on the object mounted on the jig;
And a surface modifying unit for performing an ultrasonic nano-crystal surface modification (UNSM) on the object mounted on the jig.
The surface treatment apparatus includes:
The heating section and the surface modification section are arranged at predetermined intervals or in a line,
And performing the ultrasonic nano-crystal surface modification (UNSM) by transferring the object mounted on the jig to the surface modification unit through the transfer unit after mounting the object on the jig, performing the local heating process Wherein the surface treatment apparatus comprises:
The surface treatment apparatus includes:
And a cooling unit including a cooler provided between the heating unit and the surface reforming unit,
Wherein the cooling unit is configured to cool the object while the object mounted on the jig is transferred to the surface modification unit through the transfer unit after performing the local heating process.
The surface treatment apparatus includes:
The object is fixed and the heating unit and the surface modification unit are movable by the transfer unit,
And the surface modifying unit is moved to the corresponding position by the feeding unit after the local heating process is performed at the desired position through the heating unit and the ultrasonic nano-crystal surface modification (UNSM) is continuously performed to easily perform the large- And the surface treatment apparatus is configured to be applied to the surface treatment apparatus.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020160150570A KR101910467B1 (en) | 2016-11-11 | 2016-11-11 | Surface treatment method using local heating and ultrasonic nanocrystal surface modification |
| PCT/KR2017/011074 WO2018088699A1 (en) | 2016-11-11 | 2017-09-29 | Surface treatment method using local heating and ultrasonic nanocrystal surface modification |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020160150570A KR101910467B1 (en) | 2016-11-11 | 2016-11-11 | Surface treatment method using local heating and ultrasonic nanocrystal surface modification |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20180053150A KR20180053150A (en) | 2018-05-21 |
| KR101910467B1 true KR101910467B1 (en) | 2019-01-04 |
Family
ID=62109889
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020160150570A KR101910467B1 (en) | 2016-11-11 | 2016-11-11 | Surface treatment method using local heating and ultrasonic nanocrystal surface modification |
Country Status (2)
| Country | Link |
|---|---|
| KR (1) | KR101910467B1 (en) |
| WO (1) | WO2018088699A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102100038B1 (en) * | 2018-06-15 | 2020-04-10 | 부산대학교 산학협력단 | Method and apparatus for treating wearproof metal surface |
| KR102275595B1 (en) * | 2019-02-08 | 2021-07-09 | 부산대학교 산학협력단 | High wear resistance roller and method of manufacturing the same |
| CN110317944B (en) * | 2019-06-27 | 2021-07-13 | 中国科学院宁波材料技术与工程研究所 | Residual stress relieving device |
| CN114262787B (en) * | 2020-09-16 | 2023-03-21 | 北京理工大学 | Large-scale crankshaft deformation control device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101014639B1 (en) * | 2002-09-30 | 2011-02-16 | 유겐가이샤 리나시메타리 | Method of working metal, metal body obtained by the method and metal-containing ceramic body obtained by the method |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3408687B2 (en) * | 1996-02-29 | 2003-05-19 | 三菱重工業株式会社 | Welding equipment with welding residual stress reduction device |
| US20070068605A1 (en) * | 2005-09-23 | 2007-03-29 | U.I.T., Llc | Method of metal performance improvement and protection against degradation and suppression thereof by ultrasonic impact |
| KR100894499B1 (en) * | 2008-05-14 | 2009-04-22 | (주)디자인메카 | The bearing processing system using an ultrasonic nano crystal surface modifier and processing method using the same |
| KR100989596B1 (en) * | 2008-09-04 | 2010-10-25 | 주식회사 포스코 | STS Cold mill long service life wiper roll by using an ultrasonic nano crystal surface modification technology |
| JP2012107262A (en) * | 2009-03-12 | 2012-06-07 | Yoshimi Seisakusho:Kk | Method of producing member composed of shape memory alloy and actuator utilizing member composed of shape memory alloy |
| KR20120064222A (en) * | 2010-12-09 | 2012-06-19 | 재단법인 국방기술품질원 | Ultrasonic nano-modifying apparatus and method for track pin of infinite track device |
-
2016
- 2016-11-11 KR KR1020160150570A patent/KR101910467B1/en active IP Right Grant
-
2017
- 2017-09-29 WO PCT/KR2017/011074 patent/WO2018088699A1/en active Application Filing
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101014639B1 (en) * | 2002-09-30 | 2011-02-16 | 유겐가이샤 리나시메타리 | Method of working metal, metal body obtained by the method and metal-containing ceramic body obtained by the method |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20180053150A (en) | 2018-05-21 |
| WO2018088699A1 (en) | 2018-05-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101910467B1 (en) | Surface treatment method using local heating and ultrasonic nanocrystal surface modification | |
| Farrahi et al. | An investigation into the effect of various surface treatments on fatigue life of a tool steel | |
| US7621201B2 (en) | Hot forming tools for aluminum and magnesium sheets | |
| CN105385829B (en) | A kind of surface controllable composite strengthening method of forged steel crankshaft material | |
| JP5299140B2 (en) | MATERIAL OF SHOT PEENING PROJECTION MATERIAL AND METHOD FOR PRODUCING SHOT PEENING PROJECTION MATERIAL | |
| KR101722239B1 (en) | Surface treatment method using thermal spray coating and ultrasonic nanocrystal surface modification | |
| CN107110208B (en) | Bearing components and manufacturing method | |
| Harada et al. | Effects of microshot peening on surface characteristics of high-speed tool steel | |
| CN108866472A (en) | A kind of metallic material surface treating method | |
| US8434340B2 (en) | Method for forming a stamped metal part | |
| CN104498692B (en) | A kind of cold drawing steel tube core and preparation method thereof | |
| US6688148B1 (en) | Manufacturing process for making engine components of high carbon content steel using cold forming techniques | |
| CN116144909A (en) | Non-quenched and tempered steel motor shaft and preparation method and application thereof | |
| JP2003253422A (en) | Method for prolonging service life of tool such as mandrel and forming die, and tool of prolonged service life such as mandrel and forming die | |
| JP2015151562A (en) | Local surface strengthened member and method of strengthening local surface | |
| WO2006098346A1 (en) | Method for heat-treating steel material | |
| KR102192892B1 (en) | heat treatment and Surface propagation method of Metalwork | |
| JP5890145B2 (en) | Screw shaft and manufacturing method thereof | |
| KR20100107874A (en) | A method for the surface treatmet of mold | |
| JP2007270345A (en) | Method for producing member for transport equipment | |
| CN112384637A (en) | Martensitic stainless steel strip and method for producing same | |
| JP4131389B2 (en) | Shot peening method | |
| KR101166671B1 (en) | A method for manufacturing of pump piston for fuel injection pump of 4 stroke diesel engine | |
| EP2764127B1 (en) | A process to improve fatigue strength of micro alloy steels, forged parts made from the process and an apparatus to execute the process | |
| CN109837365A (en) | Hot-work die and its composite modified layer and surface modifying method on surface |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E902 | Notification of reason for refusal | ||
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant |