JP2007277468A - Lubricant film-forming agent for plastic working of metal, metal material for plastic working of metal, and its inspection process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means capable of securing uniform dispersibility of a fluorescent material before and after coating and capable of securing uniform dispersibility of a fluorescent material in a film before and after plastic working when processing conditions, adequateness for workability, or insufficient adhesion of the lubricant film is analyzed using the fluorescent material conveniently at a low cost in the field of metal plastic working technology using a coating-type aqueous lubricant film-forming agent. <P>SOLUTION: The coating-type aqueous lubricant film-forming agent for plastic working of metals further contains an aqueous fluorescent dye in addition to an aqueous base component and if necessary a lubricant component. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique that allows a processing site to easily investigate the degree of processing and processing conditions during plastic processing such as forging, drawing, wire drawing, and press processing, the state of a mold, and the state of adhesion of a lubricant film. More specifically, a coating type water-based lubricating film forming agent for metal plastic working for forming a solid lubricating film on a metal surface during plastic working, and a metal on which the solid lubricating film is formed using the film forming agent The present invention relates to a metal material for plastic working and a method for inspecting a lubrication state of a metal material surface subjected to plastic working using the film forming agent.

  The lubricating film for plastic working represented by a phosphate film avoids the seizure phenomenon caused by metal contact during plastic working by covering the metal surface with a dense film. The performance required for the lubricating film is diverse, such as lubricity, heat resistance, pressure resistance, etc., but the performance that is particularly important is adhesion to the material. The material surface in plastic processing of metal is subjected to shearing forces in various directions while being exposed to large friction with the mold surface and high temperature and pressure. In that environment, the lubricant film must continue to be interposed between the material and the mold, so that very strong adhesion is required. For this reason, since a lubricating film used for high-working applications is formed by reaction with a raw material, a chemical conversion treatment method such as a phosphate film exhibiting strong adhesion has been widely used. However, with the recent increase in strength of steel materials and the spread of target metals, the chemical conversion treatment has become difficult to apply due to the great difference in reactivity with the metal surfaces.

  On the other hand, instead of these chemical conversion treatment methods, a coating-type lubricating film applicable to a wide range of metal surfaces has recently been put into practical use. These are intended to ensure strong adhesion to the metal surface without causing a reaction with the target metal surface, and as a next-generation lubricating film, its wide range of application and simplicity are attracting attention. Yes. However, even with these coating-type lubricating coatings, the metal type, chemical state, pretreatment, contamination state, etc. of the target material greatly affect the adhesion. It is necessary to thoroughly investigate how much adhesion of the mold lubricating film is secured on the target metal material for cold plastic working and to what extent it can be applied to processing. In addition, poor adhesion of the lubricant film due to contamination of the surface of the target metal may lead to the destruction of the mold, so the surface condition of the processed product must be frequently investigated during continuous processing at the processing site.

  However, these investigations are not easy, and in general, by analyzing the residual state of the lubricant film on the surface of the workpiece (exposed state of the base metal) using a fluorescent X-ray analyzer or an X-ray photoelectron spectrometer, processing conditions and The reality is that the suitability to the processing degree or the analysis of the poor adhesion state of the lubricating film is performed. For this reason, expensive equipment and a lot of time and labor are required, and the emergence of a new method that can be easily investigated even at a processing site has been awaited.

Here, the present inventor studied adding a fluorescent material to a coating-type lubricating film forming agent following Patent Documents 1 to 4 in other fields, but faced various problems with respect to the application. First, a fluorescent material (especially a fluorescent material / aqueous solvent combination in the form of oil or pigment) needs to be uniformly dispersed in the lubricant film forming agent, and a surfactant was added as the dispersant. In this case, the surfactant was salted out in the drying process after coating, and as a result, it was found that the fluorescent material could not be uniformly dispersed in the film formed on the metal surface (hereinafter referred to as “No. One problem ”). Furthermore, even when a solid lubricant film in which the fluorescent material is uniformly dispersed is formed on the surface of the metal material, after the metal is subjected to plastic working, the dispersion state of the fluorescent material in the solid lubricant film is uniform. It has also been found that the situation may be lost (hereinafter referred to as “second problem”). Therefore, the present invention is a metal plastic working technique using a coating type water-based lubricating film forming agent, and it is easy and inexpensive to use a fluorescent material to analyze suitability to processing conditions and degree of processing or analysis of poor adhesion of a lubricating film. In achieving the above, it is an object to provide means capable of ensuring the uniform dispersibility of the fluorescent material before and after coating and ensuring the uniform dispersibility of the fluorescent material in the film before and after plastic working.
JP-A-4-153298 Japanese Patent No. 2959661 JP-A-6-174431 Japanese Patent Publication No. 8-20366

  As a result of diligent research on the solution of the above problem, the present inventor firstly solved the “first problem” stably from various fluorescent materials in the liquid regardless of the presence of the surfactant. Alternatively, a fluorescent material that disperses was selected. Specifically, since the liquid medium of the lubricant film forming agent is aqueous, for example, instead of “oil-based” fluorescent materials such as coumarin derivatives, bisoxazoles, and pyrazoline derivatives, “water-based” materials are adopted, and the same interface is used. Instead of a “pigment” fluorescent material that requires an activator, a “dye” material was used. Furthermore, regarding the “second problem”, it was found that the problem was caused by the wax melted during processing. That is, when a wax that is normally oily is melted during the processing, if the fluorescent material is not aqueous, the fluorescent material is taken into the melted wax. In this case, when the wax once melted is solidified, it does not solidify only on the portion where the base material exists, so if the wax solidifies at a portion where the base material does not exist, the film does not exist. Regardless, the detection result is “present”. Based on these causes, if the fluorescent material is not taken into the wax, that is, if a fluorescent material having low compatibility with the wax is used, the fluorescent material is present in a uniformly dispersed state in the base layer. The present inventors have found that a simple detection result can be obtained and completed the present inventions (1) to (6).

  That is, the present invention (1) is a coating film type water-based lubricating film forming agent for metal plastic working containing an aqueous base component and optionally a lubricating component, further comprising an aqueous fluorescent dye. It is.

  The present invention (2) is the lubricant film forming agent of the invention (1), wherein the lubricating component is oily.

  The present invention (3) is the lubricating film forming agent according to the invention (1) or (2), wherein the content of the aqueous fluorescent dye is 0.5 to 10% by mass on the basis of the solid content.

  The invention (4) is any one of the inventions (1) to (3), wherein the aqueous fluorescent dye is at least one selected from a bis (triazinylamino) stilbene disulfonic acid derivative and a bisstyryl biphenyl derivative. One lubricant film forming agent.

  The present invention (5) is a metal material for plastic working in which a solid lubricant film is formed on the surface by any one of the lubricant film forming agents of the inventions (1) to (4).

  The present invention (6) is a metal material for plastic working that confirms the presence state of a solid lubricating film from the fluorescence emitted by irradiating the surface of the metal material for plastic working of the invention (5) with ultraviolet rays of 300 to 400 nm. This is an inspection method.

  According to the present invention, the uniform dispersibility of the fluorescent material is ensured before and after coating, and the uniform dispersibility of the fluorescent material in the film is also ensured before and after plastic working. Therefore, a metal material for cold plastic working having a solid lubricating film on a metal surface can be processed simply by irradiating ultraviolet rays and measuring luminescence without using expensive equipment such as fluorescent X-rays and much labor. There is an effect that the suitability to the processing degree and processing conditions or the adhesion of the lubricating film can be easily investigated at the processing site.

  Hereinafter, the coating-type water-based lubricating film forming agent according to the present invention will be described first, and then the method of using the film forming agent {that is, the method for producing a metal material for plastic working with a solid lubricating film formed thereon, the present film forming agent The method for confirming the presence state of the solid lubricating film by using (a method for inspecting the metal material for plastic working)} will be described. The “existing state of the solid lubricating film” in the claims and the specification means the application state of the solid lubricating film on the surface of the metal material before plastic working and / or the surface of the metal material after plastic working. Indicates the remaining state of the solid lubricating film. In view of the main effect of the present invention, the term “existing state of the solid lubricating film” essentially includes “the remaining state of the solid lubricating film on the surface of the metal material after plastic working”. Get good.

  First, the coating-type aqueous lubricating film forming agent according to the present invention uses an aqueous solvent as a solvent, and contains an aqueous fluorescent dye, an aqueous base component, and optionally a lubricating component. Here, in addition to a type that can be used as it is, a concentrated type that is diluted with a solvent at the time of use and a dry type that is added with a solvent are also included in the concept of the lubricant film forming agent. In the following, description will be made by taking as an example a coating-type lubricant film forming agent (treatment liquid) that can be used as it is. Hereinafter, each component will be described in detail.

  First, examples of the aqueous solvent include water and water added with a water-miscible organic solvent (for example, methanol, isopropanol, acetone, etc.).

  Next, the aqueous fluorescent dye is not particularly limited as long as it is a water-soluble fluorescent dye, and examples thereof include bis (triazinylamino) stilbene disulfonic acid derivatives and bisstyryl biphenyl derivatives. By using such an aqueous fluorescent dye, a uniform distribution in the aqueous lubricating film before and after processing is ensured. Here, the content of the aqueous fluorescent dye in the coating-type lubricant film forming agent (or “content of the aqueous fluorescent dye contained in the solid lubricant film”) is 0.5 to 0.5 on the basis of the total solid content. It is preferable that it is 10 mass%. If the content is less than 0.5% by mass, the fluorescence intensity is too low, and the remaining state of the film after processing cannot be sufficiently observed, which is not practical. On the other hand, if the content exceeds 10% by mass, the fluorescence intensity is saturated and not only economically wasteful, but also adversely affects the performance of the lubricating film. The term “aqueous” or “water-soluble” in the claims and the present specification means, for example, that 0.5 g or more is dissolved in 100 ml of water at room temperature, and preferably 1 g to It means to dissolve 50g.

  Next, the water-based base component forms a strong continuous film on the metal surface, thereby exhibiting the function of avoiding direct metal contact between the workpiece and the tool, the function of retaining the aqueous fluorescent dye, etc. in the film. To do. As such an aqueous base component, those capable of forming a coating-type lubricating film are suitable from the viewpoint of industrial ease of use, and examples thereof include aqueous inorganic salts, aqueous organic acid salts, and aqueous resins. In particular, water-based inorganic salts generally have a melting point higher than the material arrival temperature during plastic processing (cold plastic processing, warm plastic processing), so the lubricating coating layer based on these is affected by processing heat. It is difficult to show the above functions stably. Here, examples of the aqueous inorganic salt include borate, silicate, sulfate, phosphate, zirconate, molybdate, tungstate and the like. Sodium sulfate, potassium sulfate, potassium silicate, sodium borate (sodium tetraborate), potassium borate (such as potassium tetraborate), ammonium borate (such as ammonium tetraborate), ammonium molybdate, sodium molybdate, Sodium tungstate, etc.}, examples of the aqueous organic acid salt include citrate, tartrate, gluconate and the like, and examples of the aqueous resin include acrylic resin, acrylic styrene resin, urethane resin, epoxy resin, A phenol resin, a polyester resin, etc. are mentioned. These may be used alone or in combination of two or more. In addition, as a thing excellent in the applicability to a strong processing use, it is suitable to use aqueous inorganic salt with high heat resistance as a base component. Here, the content of the base component in the coating-type lubricant film forming agent (or “content of the base component to be included in the solid lubricant film”) is 5 to 99.5 mass based on the total solid content. % Is preferred.

  Next, soap, metal soap, oil and fat, mineral oil, paraffin wax, polyethylene wax, polytetrafluoroethylene, molybdenum disulfide, graphite, boron nitride and the like can be used as the lubricating component. In particular, as the lubricating component, it is preferable to use an oily component having low compatibility with the aqueous fluorescent dye so that the aqueous fluorescent dye is not taken in when melted by heat during plastic processing. Is preferred. In particular, a wax having a melting point of 70 to 150 ° C. is suitable. For example, polyethylene wax, polypropylene wax, carnauba wax, beeswax, paraffin wax, microcrystalline wax, polytetrafluoroethylene (for example, the degree of polymerization is about 1 million to 10 million) And the like. Of these, polyethylene wax and polymer waxes such as polytetrafluoroethylene are particularly suitable. The lubrication component is present on the surface of the film to be formed or inside the film. Here, the content of the lubricating component in the coating-type lubricating film forming agent (or “content of the lubricating component contained in the solid lubricating film”) is 0 to 95% by mass based on the total solid content. Preferably there is. When forming the film for plastic working, only the seizure resistance is imparted by forming a film of the aqueous base component alone, and the plastic working may be performed while contacting with oil or soap. In such a case, the surface treatment agent does not need to contain this lubricating component.

  Furthermore, this film forming agent may contain other components as required. For example, when a surfactant is required to disperse or emulsify wax, etc., it is selected from nonionic surfactants, anionic surfactants, amphoteric surfactants, cationic surfactants, etc. A dispersant may be contained. Further, in the case of plastic working that is more severe, extreme pressure additives may be contained. In general, a polycarboxylic acid-based dispersant having a weight average molecular weight of 1000 to 30000, carboxymethyl cellulose, hydroxyethyl cellulose and the like are used, and they are usually blended in a range of 0 to 20 wt% as a solid content ratio with the wax.

  Next, a method of using the present film forming agent, specifically, a method of applying the present film forming agent to the surface of a metal material (in other words, a method of forming a film of a metal material for plastic working using the present film forming agent) A method for producing a metal material for plastic working having a solid lubricating film formed thereon will be described.

  First, the metal material for plastic working that can use this film-forming agent is not particularly limited, for example, iron, steel, stainless steel, aluminum, copper, titanium, etc., all of which are subject to cold or warm plastic working. Of metals are included. Further, the material may be any of a rod, a tube, a flat material, and a sintered material. In addition, various metal plating, surface treatment, chemical conversion treatment, etc. may be given to these metal surfaces. Among these metal materials, iron, steel, and stainless steel are often used.

Next, when applying the present film forming agent to a metal material, conventional methods can be applied as they are, for example, roll coating, shower ringer roll drawing, spraying, dipping, curtain coating, flow coating, spin coating, etc. Is possible. Of these, dipping is preferred. And when implementing the said process, it is suitable that contact time shall be 0.5 second-10 minutes, and contact temperature shall be normal temperature-80 degreeC. As for the coating amount, in order to ensure the coating performance and adhesion, a coating with a dry adhesion weight of 1 to 20 g / m ² (more preferably 5 to 20 g / m ² ) is formed on the surface of the metal material. It is preferable to apply under conditions.

  Next, the drying process will be described. First, as a drying method, a conventional method can be applied as it is, and examples thereof include heat drying and air drying. For example, the solvent can be removed and a film can be formed by applying hot air of 50 ° C. to 150 ° C. for 0.5 minutes to 10 minutes and drying.

  Next, an inspection method for a metal material for plastic working that confirms the existence state of the solid lubricant film using the metal material for plastic working formed with the solid lubricant film using the present film forming agent will be described. First, a plastic working metal material on which a solid lubricating film is formed using the film forming agent is subjected to plastic working. Here, the plastic working needs to be not higher than the decomposition temperature of the aqueous fluorescent dye, and for example, is preferably plastic working (cold plastic working, warm plastic working) of 450 ° C. or lower. And after plastic working, in order to inspect the state of the lubricating film remaining on the processed surface, ultraviolet rays of 300 to 400 nm are irradiated. Here, a commercially available black light is mentioned as a simple thing as an irradiation apparatus to be used. As a method for measuring the fluorescence emitted from the fluorescent dye contained in the remaining film by irradiating with ultraviolet rays, it is a simple inspection method to evaluate the remaining state of the lubricating film by visual observation. It is also possible to store an image by, for example, and to quantify the amount of remaining film by converting the fluorescence intensity into a numerical value by image processing. Furthermore, by converting the fluorescence received using an optical sensor such as a CCD or CMOS into a voltage by a preamplifier or the like, and converting this into a coating amount, the remaining coating amount can be obtained in real time at the processing site.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these Examples.

Examples 1-4 and Comparative Examples 1 and 2
Examples 1 to 4 and Comparative Examples 1 and 2 are shown in Table 1 together with the results. Details of these test methods and evaluation methods will be described below.
<Composition of solid lubricant film and fluorescent dye>
25 parts by weight of an aqueous dispersion of 20% by weight of each lubricating component was blended with 100 parts by weight of a 5% by weight aqueous solution of each aqueous inorganic salt to prepare a film treatment liquid. About what mix | blends a fluorescent dye, each fluorescent dye of predetermined amount was stirred and mixed with respect to this film processing liquid.
<Plastic processing specimen>
A test piece whose surface has been degreased with acetone is immersed in the above-mentioned coating solution for 1 minute to apply the coating solution, and then dried in a hot air drying oven at 100 ° C. for 5 minutes to produce a plastic processing test piece. did. (Test piece material) S45C spheroidized annealing material (25 mmφ × 30 mm)
<Uniform miscibility>
The uniform miscibility after the fluorescent dye was stirred and mixed with the above-described film treatment liquid comprising an aqueous inorganic salt and a lubricating component was evaluated. As an evaluation method, 150 mL of the film treatment solution is put in a 200 mL tall beaker, and after standing for 5 minutes in the dark, irradiated with ultraviolet light with a commercially available black light, the distribution state of the emitted fluorescence is uniform in the film treatment solution. The miscibility was evaluated.
Evaluation criteria: ○: Mixed uniformly.
X: A concentration gradient or separation state is observed in the distribution of fluorescence.
<Plastic workability>
Spike test processing according to the invention of Japanese Patent No. 3227721 was performed on the plastic working test piece created by the above-described method, and the degree of film follow-up to the protruding portion of the test piece after processing and the presence or absence of seizure portions were visually evaluated. . Those having good followability have sufficient seizure resistance against surface area expansion during cold plastic working, and seizure is likely to occur if the coating does not follow.
Evaluation criteria: ○: The film follows up to the protruding part, and there is no seized part.
Δ: The film does not follow up to the protruding part, but there is no seized part.
×: The film does not follow the protrusion, and there is a seizure part <Residual film evaluation>
From the visual observation of the fluorescence emitted by irradiating ultraviolet rays with a commercially available black light in the dark about the processed part (projection part wall surface) of the test piece subjected to cold plastic processing during the evaluation of plastic workability as described above It was evaluated whether or not the remaining state could be confirmed.
Evaluation criteria: ○: The state of the remaining film was confirmed from the thick film part to the thin film part.
(Triangle | delta): The fluorescence was weak and the state of the residual film | membrane was confirmed about the thick film part.
×: Since it does not emit fluorescence or is too weak, the state of the remaining film can be confirmed visually.
I didn't.

  As is apparent from the results in Table 1, Examples 1-4, which are metal materials for cold plastic working of the present invention, have various performances necessary for practical use such as uniform miscibility, plastic workability, and evaluation of the remaining film. All were satisfied. On the other hand, in Comparative Example 1 in which the fluorescent dye is not contained in the solid lubricating film on the surface of the metal material for cold plastic working of the present invention, it is impossible to evaluate the remaining film after processing, and the oily fluorescent dye outside the present invention In Comparative Example 2 blended, uniform mixing was not possible in the solid lubricating film.

Example 5
A bis (triazinylamino) stilbene disulfonic acid derivative was blended with a commercially available coating-type lubricating coating agent so that the solid content ratio was 5% by mass. By forming a coating on the surface of the test piece so as to have a coating amount of 10 g / m ² , the solid lubricating coating of the present invention and a metal material for cold plastic working having the coating on the surface are prepared and shown in FIG. The ball threading test was conducted at the following two processing degrees.
Commercially available coating type lubricant film: FineLube E875
(Nippon Parkerizing Co., Ltd.)
(Main component: aqueous inorganic composite salt + polyolefin-based lubricating component)
Test piece material: cylindrical S10C pickling material, outer diameter 30 mmφ × height 50 mm,
Two types of inner diameter 14.5mmφ and 15.0mmφ.
The ball is SUJ-2 material of 17.46mmφ.
Degree of processing: 12% reduction in cross-sectional area (uses inner diameter of 15.0 mmφ)
Cross-sectional area reduction rate of 14% (using an inner diameter of 14.5 mm)

  FIG. 2 shows a fluorescent image photograph of the inner wall portion after the ball passing test, which was taken with a digital camera while irradiating with ultraviolet light from a black light in the dark. It can be visually observed that the remaining area of the film is worse when the cross-sectional area reduction rate of 14% having a higher workability is higher, and that the metal material for cold plastic working is more stable at a workability of a cross-sectional area reduction rate of 12%. I understand.

  The processed portion on the fluorescent image photograph was subjected to image processing to measure the darkness (low fluorescent intensity) K value, and the transition of the film remaining state with respect to the processing sliding direction was investigated. The result is shown in FIG. Subsequently, the degree of exposure of iron on the surface of the same product was measured using an X-ray photoelectron spectrometer, and the transition of the film remaining state was similarly compared. The result is shown in FIG. Note that the measurement with the X-ray photoelectron spectrometer took a lot of time and labor, and therefore the number of measurement points was greatly reduced.

  The results shown in FIGS. 3 and 4 are in agreement with the results of the visual observation described above, and the remaining area of the film is clearly inferior when compared with 12% when the cross-sectional area reduction rate is 14%, which has a higher degree of processing. It is shown. From these results, according to the inspection method of the present invention, it is possible to easily investigate the residual film state after processing at the processing site without using an expensive surface analysis device and to quantify the state. Proven to be.

FIG. 1 is a schematic diagram of a ball threading test in the example. FIG. 2 is a fluorescent image photograph of the inner wall portion after the ball threading test in the example. FIG. 3 shows the transition result of the film remaining state with respect to the machining sliding direction based on the present invention. FIG. 4 shows the transition result of the remaining film state with respect to the machining sliding direction based on the conventional method.

Claims (6)

  A coating film type water-based lubricating film forming agent for metal plastic working, which contains an aqueous base component and optionally a lubricating component, further comprising an aqueous fluorescent dye.   The lubricating film-forming agent according to claim 1, wherein the lubricating component is oily.   The lubricating film-forming agent according to claim 1 or 2, wherein the content of the aqueous fluorescent dye is 0.5 to 10% by mass based on solid content.   The lubricating film forming agent according to any one of claims 1 to 3, wherein the aqueous fluorescent dye is at least one selected from a bis (triazinylamino) stilbene disulfonic acid derivative and a bisstyryl biphenyl derivative.   A metal material for plastic working, wherein a solid lubricating film is formed on the surface by the lubricating film forming agent according to any one of claims 1 to 4. A method for inspecting a metal material for plastic working, wherein the surface state of the metal material for plastic working according to claim 5 is confirmed from the fluorescence emitted by irradiating ultraviolet rays of 300 to 400 nm.