JP2013250095A - Wet developer for penetrant test and developing method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wet developer suppressing deformation and excessive expansion of a defect indication pattern due to bleeding generated when developing with a wet developer in a penetrant test, with passage of time and capable of adjusting the defect indication pattern in a desired size.SOLUTION: The wet developer for a penetrant test is characterized in that inorganic white powder is scattered in water in which water-soluble resin is dissolved.

Description

  The present invention relates to a wet developer used in a penetrant flaw detection test applied to flaw detection of fine opening defect portions existing on the surface of various members such as automobile members, and a developing method using the developer.

  As is well known, the penetrant flaw detection standardized in “JIS Z 234-1-4”, which is a kind of nondestructive inspection method, is a fine method that exists on the surface of various members such as automobile members (for example, piston rods). It is widely used for flaw detection of fine opening defects (for example, fine cracks and pinholes), and the basic mode is as shown in the JIS standard. A method using a highly penetrating liquid dissolved in a solvent or a fluorescent penetrating liquid (usually ultraviolet light: black light: penetrating oil-soluble fluorescent dye that emits yellow-green fluorescence under irradiation in a solvent) A strong liquid is used).

  In the flaw detection test method using the dye penetrant, after the dye penetrant is adhered to the surface of the object to be infiltrated and penetrated into the opening defect portion, the excess dye remaining on the surface of the object to be inspected without penetrating into the defect portion. After removing the penetrating liquid, and then applying a developer produced by dispersing an inorganic white powder such as magnesium carbonate powder or calcium carbonate powder in a dispersion medium and adding a surfactant to the surface of the object to be inspected. A thin layer of white powder is formed, and the defect indicating pattern is revealed by sucking the dye permeation solution penetrating into the opening defect portion by the thin layer to the surface of the thin layer, under natural light or white light. Observe and detect the presence / position of the opening defect by the defect indication pattern.

  In the flaw detection test method using a fluorescent penetrating liquid, after attaching the fluorescent penetrating liquid to the surface of the inspection object and penetrating into the opening defect portion, the excess fluorescence remaining on the surface of the inspection object without penetrating the defect portion. After removing the penetrating liquid, without applying the developer, the surface of the object to be inspected is irradiated with black light in a dark place to cause the fluorescent penetrating liquid remaining in the opening defect portion to emit yellow-green light. The defect detection pattern is used to detect the presence / position of the opening defect portion, and after removing the excess permeation liquid, the developer is applied and remains in the opening defect portion in the same manner as in the case of using the dyeing permeation liquid. After the fluorescent penetrating liquid is sucked out on the surface of the thin layer, it is irradiated with black light in the dark, and the fluorescent penetrating liquid sucked out on the surface of the thin layer emits yellowish green, and the defect indication pattern of the yellowish green Detects the presence and position of opening defects That there is a manner, the developer can be more minute opening defect portion flaw better aspect to apply.

  For dyeing penetrants and fluorescent penetrants (hereinafter sometimes referred to simply as “penetrants”), products with a variety of prescriptions are commercially available and widely used, and those commercially used by those skilled in the art are oil-soluble red. Dye (for example, oil red 5B: trade name: Orient Corporation or Sudan Red 462: trade name: BASF) and oil-soluble fluorescent dye (for example, Fluorol 7GA: trade name: GAF: Fluorescent Bright Varnish Agent 68) : Product name: Nippon Kayaku Co., Ltd.), water-based dyeing penetrant / water-based fluorescent penetrant containing water and water-soluble organic solvent as main solvent And oil-based dyeing penetrants and oil-based fluorescent penetrants containing flammable water-insoluble organic solvents (usually high-boiling organic solvents) as main solvents. A dilution solvent (usually a volatile low / medium boiling organic solvent) is blended in the oil-based dyeing permeation solution and the oil-based fluorescent permeation solution.

  Oil-based dye penetrant / oil-based fluorescent penetrant generally does not remove the penetrant that has penetrated into the opening defect, compared to water-based dye penetrant / water-based fluorescent penetrant. It has higher flaw detection accuracy than water-based dyeing penetrants and water-based fluorescent penetrants, and is used to detect fine opening defects. There are regulations.

  On the other hand, water-based dye penetrant and water-based fluorescent penetrants contain water and water-soluble organic solvents in a proportion that does not have a flash point. There is no problem of quantity. Similarly, if the dispersion medium is water and development is performed with a wet developer that does not have a flash point, there is no need to pay attention to the use of fire around the penetration test site. This combination is widely used in automobile factories and is suitable for flaw detection of slabs at steelworks.

  However, in the developing method using the wet developer, since the dispersion medium of the developer is water, the defect indicating pattern tends to be greatly enlarged as time passes. This is because it takes time for the water to dry, so that the dye penetrating solution / fluorescent penetrating solution permeates into the gaps of the powder of the wet developer and spreads too much. 』)).

  The occurrence of blemishes adversely affects the flaw detection accuracy. For example, when two opening defect portions are adjacent to each other, even if they appear as two defect indication patterns, they overlap with each other over time and become one defect indication pattern. If the opening defect portion is linear, even if it appears as a thick linear defect instruction pattern, it will become an elliptical defect instruction pattern due to blurring over time. As described above, there is a problem in that the size and shape of the defect indicating pattern changes with time.

  Moreover, the average particle diameter of the inorganic white powder contained in the commonly used wet developer is a fine powder of less than about 4 μm, and its content is about 5 to 15% by weight. When the object to be inspected cannot be dried with a dryer after applying the wet developer due to the large size or the material that cannot be heated, it is dried by air blow etc. In order to shorten the length of the developer, a developer in which the moisture content in the wet developer is reduced and the powder content is increased to about 40 to 60% by weight is used.

  In the case of a developer having a powder content of about 40 to 60% by weight, when the average particle size is generally used, it is a fine powder having a mean particle size of less than about 4 μm, and the viscosity increases and a uniform thin layer is formed. Since it cannot thicken and becomes uneven and does not function as a developer, a large powder having an average particle diameter of about 4 to 8 μm is used so that the viscosity does not increase even if the powder content is large.

  However, as the average particle size of the powder increases, the gap between the powders increases, and when the staining penetrating solution / fluorescent penetrating solution remaining in the opening defect portion is sucked into the thin layer, the dyeing penetrating solution / fluorescent solution is absorbed into the large gap. Since the penetrating liquid penetrates, the blurring is further expanded as compared with a general wet developer using a fine powder having an average particle size of less than about 4 μm, and accurate detection (flaw detection) of an opening defect portion becomes more difficult. There is a problem.

  The present inventor has made it a technical subject to solve the above-mentioned problems, and as a result of many trial and error trial manufactures and experiments, the inventors have added a water-soluble resin even if it is a wet developer. The presence of a water-soluble resin around the powder contained in the layer, and the water-soluble resin takes in and hardens the dye permeation solution / fluorescent permeation solution that penetrates into the gap from the opening defect portion, so the defect indication pattern blurring does not spread too much, In addition, we have obtained a remarkable knowledge that the defect indication pattern can be adjusted to a desired size by adjusting the spread of blistering by selecting and using the type and / or addition amount of the water-soluble resin. The technical problem has been achieved.

  The technical problem can be solved by the present invention as follows.

  That is, the present invention is a wet developer for a penetrant flaw detection test characterized in that an inorganic white powder is dispersed in water in which a water-soluble resin is dissolved (claim 1).

  The present invention is the wet developer for penetrant flaw detection according to claim 1, wherein the content of the water-soluble resin is 0.1 to 5% by weight (claim 2).

  Further, in the present invention, the water-soluble resin is at least one selected from a water-soluble acrylic ester resin, a water-soluble carboxymethyl cellulose resin, and a water-soluble polyvinyl alcohol resin. It is a wet developer (claim 3).

  Further, the present invention provides the wet developer for penetrant flaw detection according to any one of claims 1 to 3, wherein the inorganic white powder has an average particle size of 4 to 8 µm.

  Further, the present invention is the wet developer for penetrant flaw detection according to any one of claims 1 to 4, wherein the content of the inorganic white powder is 40 to 60% by weight (claim 5).

  In the present invention, the inorganic white powder is magnesium carbonate and / or calcium carbonate. The wet developer for penetrant flaw detection according to any one of claims 1 to 5 (claim 6).

  In addition, the present invention is a developing method in a penetrant flaw detection test using the wet developer for penetrant flaw test according to any one of claims 1 to 6 (claim 7).

  Further, the present invention is the developing method in the penetrant flaw detection test according to claim 7, wherein the size of the defect indicating pattern is adjusted by selecting and using the content and / or type of the water-soluble resin. 8).

  Since the present invention is a wet developer for penetrant flaw testing characterized in that an inorganic white powder is dispersed in water in which the water-soluble resin is dissolved, the water-soluble resin is present in the gap between the powders, The water-soluble resin takes in the dyeing and fluorescent penetrating liquids that penetrate into the gaps between the powders and hardens them to suppress the excessive expansion of the blisters, so the size and shape of the defect indication pattern changes over time. This makes it difficult to accurately detect (detect flaws) the opening defect portion.

  In addition, if the water-soluble resin added to the wet developer of the present invention is changed in the range of 0.1 to 5% by weight, the spread of blurring can be adjusted, so that, for example, visual detection is easy. It is possible to adjust the size of the defect indication pattern to a desired size so that the defect indication patterns of the adjacent opening defect portions do not overlap.

  Further, if the water-soluble resin to be added is at least one selected from water-soluble acrylic ester resins, water-soluble carboxymethyl cellulose resins, and water-soluble polyvinyl alcohol resins, it is easy to dissolve in water and the wet developer itself. Therefore, even if added to the developer, a uniform thin layer can be formed.

  Further, the wet developer using the powder having the inorganic white powder content of 40 to 60% by weight and the average particle size of 4 to 8 μm has a large average particle size of the powder, so that the gap between the particles becomes large and the blurring is enlarged. However, it is possible to accurately detect (flaw detection) an opening defect because it is possible to suppress the excessive expansion of bleeding by surrounding and solidifying the dye penetrant / fluorescent penetrant into which the water-soluble resin penetrates. .

  Moreover, since a uniform white thin layer can be formed by making the inorganic white powder magnesium carbonate and / or calcium carbonate having high whiteness and excellent quick drying properties, a defect indication pattern can be clearly revealed, An opening defect can be accurately detected (flaw detection).

  Furthermore, the penetrant flaw detection test method using the wet developer of the present invention can suppress the excessive expansion of the staining penetrant / fluorescent penetrant, and if necessary, the water-soluble resin contained in the wet developer. By selecting and using the quantity and / or type, the defect indicating pattern can be adjusted to a desired size.

  In addition, since the present invention can be used in combination with a commercially available dye penetrant / fluorescent penetrant, it can be used for penetrant testing of opening defects of various sizes and depths.

It is the figure which showed that the diameter of the substantially circular defect instruction pattern became small with addition of water-soluble resin.

  The embodiment of the present invention is as follows.

  The wet developer for penetrant flaw detection test of the present invention is produced by dispersing an inorganic white powder in water and adding a water-soluble resin.

  The inorganic white powder used in the present invention is not particularly limited, and examples thereof include magnesium carbonate powder, calcium carbonate powder, anhydrous silicic acid powder, and hydrous silicic acid powder. In particular, magnesium carbonate powder and calcium carbonate powder can be suitably used because of their high whiteness.

  The average particle size of the inorganic white powder is not particularly limited, and is used when the powder content is about 40 to 60% by weight as well as the fine powder generally used with an average particle size of less than about 4 μm. A powder having an average particle size of about 4 to 8 μm can also be used.

  In addition, when the average particle diameter of the powder is larger than about 8 μm, the dispersibility at the time of producing the developer or forming the thin layer is deteriorated.

  The content of the inorganic white powder in the present invention is 5 to 60% by weight, preferably 40 to 60% by weight. If the amount is less than 5% by weight, a thin layer of the developer may not be formed. If the amount is more than 60% by weight, the viscosity of the wet developer increases, and the developer does not become a thin layer. It is not preferable because it does not function as an agent.

  As the water-soluble resin in the present invention, any of natural, semi-synthetic and synthetic water-soluble resins can be used, but acrylate-based water-soluble polymers are preferred. Preferred acrylate-based water-soluble polymers include styrene-acrylate copolymer resins, styrene-acrylate ester special copolymer resins, styrene- (meth) -acrylate ester copolymer resins, and vinyl acetate-acrylic acid copolymers. Examples thereof include resins, acrylic ester copolymer resins, and acrylic ester special copolymer resins.

  In addition, cellulose-based semi-synthetic water-soluble resins such as water-soluble carboxymethyl cellulose and water-soluble hydroxymethyl cellulose, and synthetic water-soluble resins such as water-soluble polyvinyl alcohol can also be suitably used.

  The content of the water-soluble resin is preferably 0.1% by weight or more, and more preferably 0.1 to 5% by weight. If it is less than 0.1% by weight, the penetrating liquid penetrating into the gaps between the powders cannot be sufficiently absorbed, and there is a possibility that the bleeding will spread too much. There is no change in the inhibitory effect on the toner, and when the viscosity of the wet developer increases, it becomes difficult to form a uniform thin layer, which is not preferable.

  In the present invention, a surfactant can be added to sufficiently disperse the inorganic white powder. The surfactant to be added is preferably a nonionic surfactant. For example, Neugen XL-40, HLB: 10.5 (trade name: Daiichi Kogyo Seiyaku Co., Ltd.), Neugen LF-30X, HLB: 9.4 ( Trade name: Daiichi Kogyo Seiyaku Co., Ltd.), Neugen DKS NL-60, HLB: 11.5 (trade name: Daiichi Kogyo Seiyaku Co., Ltd.). Although the addition amount of surfactant is not limited, 0.1 to 3.0 weight% is preferable, More preferably, it is 0.5 to 1.0 weight%.

(Preparation of wet developer)
Preparation of a wet developer for penetrant testing according to the present embodiment is easy, after adding an inorganic white powder and a surfactant while stirring water using a propeller-type stirrer, and adding a water-soluble resin Stir until the whole is uniform.

(Penetration testing method)
In the penetrant testing method according to the present embodiment, first, a commercially available penetrant for penetrant testing is applied to the surface of an object to be inspected and permeated into an opening defect portion (penetration treatment). Washing / removing excess permeate remaining on the surface of the object without penetrating into the defective part at a water pressure of about 0.1 to 0.3 Mpa and a flow rate of 1 to 3 L / min (cleaning process) ).

  After removing water droplets remaining on the surface of the object to be inspected by air blow or the like, a wet developer is applied and dried by a dryer or air blow to form a thin layer of developer (development process).

  The penetrating liquid remaining in the opening defect portion is sucked out by a thin layer of the developer and a defect indicating pattern appears. The diameter of the displayed indication pattern is measured using a caliper.

  In the case where the appearance of the defect indicating pattern appears to be too wide and the adjacent defect indicating patterns overlap each other, the amount and / or type of the water-soluble resin is changed and adjusted to an appropriate size.

  After selecting and determining the addition amount and / or type of the water-soluble resin, if the same wet developer is used, the size and depth of the opening defect can be compared (detected). .

(Preparation of wet developer)
Fill a glass beaker with the required amount of water and stir at 300 rpm using a propeller-type stirrer with the required amount of surfactant (Neugen XL-40 (HLB: 10.5)) and the required amount of white calcium carbonate. Powder (average particle size 6 μm) is added, and then the required amount of styrene-acrylic ester copolymer resin (Polysol SE-1420: trade name: Showa Denko KK) is added and stirred until the whole becomes uniform. Subsequently, a wet developer was produced. Further, a wet developer produced in the same manner as described above except that no water-soluble resin was added was used as a comparative example. Each addition amount and the amount of water are as described in Table 1.

(Evaluation method of the size of defect indication pattern)
Using an artificial defect test piece having a drill hole with a diameter of 0.5 mm and a depth of 5 mm on an aluminum plate having a thickness of 10 mm, and using Super Check P-LK (trade name: Marktech Co., Ltd.) as a dyeing penetrant, After applying to the artificial defect test piece with a brush and infiltrating for 5 minutes, the excess dyeing permeate was removed by spray cleaning at a water pressure of 150 kPa, and then water droplets adhering to the surface of the artificial defect test piece were removed by air blowing. Thereafter, the wet developer was spray-applied to the artificial defect test piece with a spray gun, and the diameter of the substantially circular defect indicating pattern which appeared after drying at 70 ° C. for 5 minutes was measured with a caliper using a hot air circulation dryer.

  Table 1 and FIG. 1 show the average value of the diameter of the substantially circular defect indicating pattern measured by repeating the above operation three times as the size (mm) of the indicating pattern.

  When Super Glow OD-18S (trade name: Marktec Co., Ltd.), which is a commercially available fluorescent penetrant for penetrant flaw detection test, was used, it was exposed to black light in a dark place after (development processing). Measure the diameter of the defect indication pattern with a caliper.

  If Polysol SE-1420 is added, the average particle diameter of the inorganic white powder is large because the average value of the diameter of the substantially circular defect indicating pattern is smaller than when not added (Comparative Example). Even in such a case, it is possible to accurately detect (detect flaws) the opening defect portion while suppressing the excessive expansion of bleeding.

  Further, when the amount of polyzole SE-1420 added is 0.1 to 0.5% by weight, the diameter of the substantially circular defect indicating pattern becomes smaller with the increase in the amount added, so that the size of the opening defect portion is increased. By adjusting the addition amount of the water-soluble resin depending on the thickness, it is possible to suppress the overlapping of adjacent defect indicating patterns and accurately detect (detect flaws) the opening defect portion.

(Comparison of water-soluble resin types)
Same as above, using 50 cc of water, 0.5 g of surfactant (Neugen XL-40 (HLB: 10.5)), 47.5 g of calcium carbonate white powder (average particle size 6 μm), and 2.0 g of various water-soluble resins. The wet developer was manufactured, and the diameter of the substantially circular defect indicating pattern was measured three times by the same method as the evaluation method, and the average value was taken as the size (mm) of the indicating pattern.

  The water-soluble resins used were vinyl acetate-acrylic ester copolymer resin (Polysol P-503: trade name: Showa Denko KK), acrylic ester copolymer resin (Polysol AM-200: trade name: Showa Denko KK). ), Styrene-acrylic acid ester copolymer resin (Polysol AM-610: trade name: Showa Denko KK), acrylic ester special copolymer resin (Polysol AE-710DF: trade name: Showa Denko KK), styrene ( A mixture of a meth) acrylic ester copolymer resin and a polyester resin (Polysol FP-3000A: trade name: Showa Denko KK), styrene-acrylic ester special copolymer resin (Polysol SE-1440: trade name: Showa Denko KK) ), Carboxymethyl cellulose (CMC Daicel 1120: trade name: Lee cell FineChem Co., Ltd.), polyvinyl alcohol (Gosenoru GL-03: product name: a Nippon Synthetic Chemical Industry Co., Ltd.).

  The results are shown in Table 2.

  Since the diameter of the almost circular defect indication pattern of the wet developer with water-soluble resin is smaller than that of the comparative example, excessive spread of blurring is suppressed even when the average particle size of the inorganic white powder is large. In addition, it is possible to accurately detect (detect flaws) the opening defect portion by preventing overlapping of adjacent defect instruction patterns.

In the wet developer according to the present invention, by adding a water-soluble resin, the water-soluble resin takes in and solidifies the penetrating liquid that permeates into the gaps of the powder in the thin layer of the developer from the opening defect portion. It is possible to adjust the defect indication pattern to a desired size by adjusting the spread of the blur according to the type and / or addition amount of the water-soluble resin, and accurately detecting the opening defect portion ( Therefore, it can be said that the present invention has great industrial applicability because it is suitable for a wet developer for penetrant flaw testing in automobile companies and steelworks.

Claims (8)

A wet developer for penetrant flaw detection, wherein an inorganic white powder is dispersed in water in which a water-soluble resin is dissolved. The wet developer for penetrant flaw detection according to claim 1, wherein the content of the water-soluble resin is 0.1 to 5% by weight. The wet developer for penetrant flaw detection tests according to claim 1 or 2, wherein the water-soluble resin is at least one selected from a water-soluble acrylic ester resin, a water-soluble carboxymethyl cellulose resin, and a water-soluble polyvinyl alcohol resin. The wet developer for penetrant flaw testing according to any one of claims 1 to 3, wherein the inorganic white powder has an average particle size of 4 to 8 µm. The wet developer for penetrant flaw testing according to any one of claims 1 to 4, wherein the content of the inorganic white powder is 40 to 60% by weight. The wet developer for penetrant flaw testing according to any one of claims 1 to 5, wherein the inorganic white powder is magnesium carbonate and / or calcium carbonate. A developing method in a penetrant flaw detection test using the wet developer for penetrant flaw testing according to any one of claims 1 to 6. The developing method in a penetrant flaw detection test according to claim 7, wherein the size of the defect indicating pattern is adjusted by selecting and using the content and / or type of the water-soluble resin.

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