JPS63109353A - Quick-drying type developer for dyeing penetration flaw detection test and removal thereof - Google Patents

Abstract

PURPOSE:To easily remove the developer remaining on the surface of an object to be inspected, by dispersing white inorg. fine powder in a volatile org. solvent and dissolving 0.1% or less by wt. of the org. solvent of a fluorescent dye or brightener soluble in said solvent. CONSTITUTION:A white inorg. fine powder is dispersed in a volatile org. solvent and about 0.002-0.01wt% of a fluorescent dye soluble in said solvent, about 0.03-0.06wt% of a fluorescent brightener soluble in said solvent or 0.1wt% or less of both of them is added to the solvent to be dissolved therein. As the volatile org. solvent, alcohols are used in general and, as the fluorescent dye, Fluorescent Yellow is pref. and, as the fluorescent brightener, fluoranthene is pref. As mentioned above, by adding an extremely small amount of the fluorescent dye or fluorescent brightener, each particle of the white inorg. powder forming a developer layer emits fluorescence under the irradiation of ultraviolet rays and can be easily confirmed visually and the developer remaining on the surface of an object to be inspected can be easily removed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a quick-drying developer for dye penetrant testing and a method for removing the same. The present invention provides a new technical means by which developer can be easily and completely removed.

[Conventional technology]

Surface opening defects (hereinafter referred to as ``defects'') such as minute luxes and minute pinholes that exist on the surfaces of machine parts and weld lines of structures made of metals, plastics, ceramics, etc. are well-known. non-destructive testing methods applied to the detection of (hereinafter referred to as "parts") - and as belonging to the standard penetrant testing methods indicated in the above-mentioned standards, washable dye penetrants or solvent removable dye penetrants. There is a "dye penetrant test" method that uses a liquid, which is also shown in the above standards, and a "quick-dry developing method" that uses a developer in which fine white powder is dispersed in a volatile organic solvent. In some cases, it is combined with "agent". In other words, the symbol of the test method in the above standard is ``
MA-3J and Koos designated as "VC-8".

The specific aspects of the above case will now be explained as follows.

First, "pretreatment" is performed to clean the surface of the object to be inspected by washing or the like. Next, a water-washable dye penetrant solution or a solvent-removable dye penetrant solution in which a dye (usually red) is dissolved is applied to the surface of the object to be inspected, and the solution is allowed to stand for a predetermined period of time to allow the penetrant solution to penetrate into the defects present on the surface of the object to be inspected. "Infiltration treatment" is performed to infiltrate. Next, a "cleaning/removal process" is performed to remove excess penetrating liquid that has adhered to the surface of the inspected object without penetrating into the defect by washing it with water or wiping it off using a cleaning agent (usually an organic solvent). ” will be held. At this stage, the penetrant remains only in the defect, and in this state it is difficult to visually detect the presence of the penetrant. Next, a quick-drying developer (usually carbonated Spraying or It is applied as a paint film, and the solvent is volatilized to form a developer layer (usually a thin layer with a thickness of about 20 to 50 microns) consisting of white inorganic fine powder, and between the fine powder particles forming the layer. ``Development treatment'' that uses capillary action to suck out the penetrating liquid within the defect area and creating a bleed pattern caused by the penetrating liquid on the surface of the layer, thereby enlarging the defect area and making it easier to detect visually.
will be held. Next, the bled pattern, in other words, the indication pattern, appearing on the surface of the developer layer is visually observed under visible light of 350 lux or more to determine the presence or absence and size of a defective portion.

After the above tests are completed, the developer layer formed on the surface of the test object is removed by brushing, air blowing, water spray, wiping with cloth or paper, etc.
"Post-processing" is performed.

[Problem that the invention seeks to solve]

In the ``post-processing'' of the above-mentioned conventional ``dye penetrant test'' method and ``quick-drying visual agent,'' there are the following problems. The problem is that it is very difficult to judge whether or not the particles have been completely removed.

To put it simply, the developer layer formed on the surface of the object to be inspected by applying a quick-drying developer is a dense aggregate of fine particles, and the particles themselves do not have adhesive strength. However, since they are stuck relatively firmly, if the surface of the object to be inspected has a complex shape, removing them is a tedious task, and if the removal is not done sufficiently, fine particles may form. Moreover, Φ will remain.
Issued in the 1979 edition, 3rd edition, K ``...In the development process for fluorescent penetrants, the coating surface of the developer is applied somewhat thinly, whereas in the case of dye penetrants, the coating surface is coated on the test surface. Apply the developer to such an extent that the skin of the developer can be faintly seen through the developer coating.In addition, in the case of fluorescent, the thickness of the developer should be applied to the surface of the coating to the extent that it has the effect of sucking out the penetrating liquid from the defects. However, in the case of a dye penetrant, another purpose is to make the coating surface of the developer thicker and apply white developer to the test surface in order to ensure the contrast of the indicated pattern with the red penetrant. As stated above, in dye penetrant testing, it is necessary to form a relatively thick developer layer. Particles often remain.

If the object to be inspected is plated after "post-treatment" or anti-corrosion treatment is performed using heavy chromic acid anodization, etc.,
Furthermore, when performing heat treatments such as decarbonization and nitriding, if even a small portion of the white inorganic fine powder that had formed the developer layer on the surface of the object to be inspected remains, it may cause defective products. Also,
Since white inorganic fine powder is hygroscopic, it may cause rust when the object to be inspected is steel.

Therefore, in "post-processing", it is necessary to carry out the removal work while checking the removal state of the developer layer until it is completely removed. Currently, no measures have been taken to determine this, and the current situation is that it relies entirely on visual judgment by experts.

However, no matter how skilled a person is, it is extremely difficult to carry out the removal work until complete removal is possible while checking whether even one or two fine particles remain. In particular, if the light source in the work place is not sufficient, it is impossible to determine whether or not the dust has been completely removed.

In view of the current situation, the inventors of the present invention have conducted repeated research on the technical issue of providing a technical means that allows the developer layer to be easily removed by visual inspection. The above-mentioned problem has been successfully solved by making it possible to easily identify each grain by visual inspection.

[Means for solving problems]

That is, the present invention provides a dye penetrant flaw detection method in which white inorganic fine powder is dispersed in a volatile organic solvent and 0.1% by weight or less of a soluble fluorescent dye and/or fluorescent brightener is dissolved in the solvent. Applying the quick-drying developer for testing (first invention) and the quick-drying developer for dye penetrant testing to the surface of the object to be inspected,
A developer layer made of white inorganic fine powder dyed with a fluorescent dye or/and a fluorescent whitening agent is formed, and when the developer layer is removed after the dyeing flaw detection test, the inspection target is removed. Removal of a quick-drying developer for dye penetrant testing, characterized by irradiating the surface of an object with an ultraviolet lamp and performing removal work until fluorescence excited by the irradiated ultraviolet light is no longer visually recognized on the surface of the object to be inspected. This is a method (second invention). The quick-drying developer according to the first invention is prepared by dissolving 0.1% by weight or less of a fluorescent dye and a fluorescent whitening agent in the well-known "quick-drying developer" described above.

Fluorescent dyes and fluorescent brighteners may be selected from commercially available products that are soluble in volatile organic solvents used in "quick-drying developers."

The volatile organic solvents used in "quick-drying developers" are usually alcohols (ethanol, methanol, Inflovir alcohol, etc.), esters (methyl acetate,
butyl acetate, etc.), ketones (methyl ethyl ketone, acetone, etc.), hydrocarbons (n-heptane, benzene,
Perchloroethylene, etc.) alone or in mixtures, so the fluorescent dyes include Flawless Yellow F.K.H (trade name manufactured by Nijirad Chemical) and Flawless Green 5G (trade name manufactured by Nijirad Chemical).
, Fluorol 5G (trade name: manufactured by BASF-), Hudson Yellow (trade name: manufactured by Daiflo Color), etc. are suitable.As the fluorescent brightener, fluoranthene (chemical name), Kikor C (trade name: Keikole E (product name: 8so Kako), Kayalai) B (product name: Nippon Kayaku), $427 (product name: Asahi Kayaku), etc. are suitable. It is.

Addition of fluorescent dyes and fluorescent brighteners (ft1dO, 1% by weight or less) has no adverse effect on the performance as a quick-drying developer, and the resulting developer Neither the penetrating liquid suction effect of the layer nor the appearance (whiteness) under visible light is any different from that of a developer layer formed by an unadded fast-drying developer.

When fluorescent dyes and fluorescent brighteners are added in very small amounts, each grain of the fine white inorganic powder that forms the developer layer emits fluorescence when exposed to ultraviolet rays, making it easily visible to the naked eye. can be taken as a thing.

The former is about 0.002 to 0.01% by weight, and the latter is 0.0% by weight.
Addition of about 3 to 0.06% by weight is suitable. If both are used in combination, the desired fluorescence can be emitted with a higher addition amount, so it is recommended to use both in combination.

The quick-drying developer according to the first invention is easy to manufacture;
A predetermined amount of the above-mentioned fluorescent dye is dispersed in a predetermined amount of the above-mentioned volatile organic solvent, in which a predetermined amount of white inorganic fine powder of magnesium carbonate, calcium carbonate, silicic acid, etc. with a particle size of 1 to 10 microns is dispersed. , the above-mentioned fluorescent whitening agent (if both are used together, the total amount should be 0.1 type bone % or less) is added, and the mixture is stirred for about 2 to 6 minutes to dissolve. Alternatively, the quick-drying developer according to the first invention can be obtained by adding the required amount of fluorescent dye and fluorescent brightener to a commercially available "quick-drying developer" and stirring and dissolving the mixture.

Incidentally, the quick-drying developer according to the first invention is also used as an aerosol type by being sealed in an aerosol can according to a conventional method, as in the case of the well-known "quick-drying developer."

Next, the method for removing quick-drying developer according to the second invention is as follows:
In the case where the "dye penetrant test" method and "quick-drying developer" are combined as described above, the quick-drying developer according to the first invention is used as the "quick-drying developer",
The "post-processing" involves irradiating the surface of the object to be inspected with an ultraviolet lamp, brushing, air blowing, water spraying, etc. until the fluorescent light excited by the irradiated ultraviolet light is no longer visible on the surface of the object to be inspected. The developer layer is removed by wiping it with cloth or paper.

As the ultraviolet light (black light), a general-purpose product used in fluorescent penetrant testing methods and fluorescent magnetic particle testing methods may be used; for example, commercially available products such as Fludge and Spurly).
The tlVF-80 type (trade name: Special Paint Co., Ltd.) is suitable.

The irradiation of the surface of the object to be inspected with an ultraviolet lamp does not necessarily have to be in a dark place, but can be in a place with enough brightness to remove the developer layer. Each particle of white inorganic fine powder in the developer layer formed by applying the quick-drying developer according to the above emits fluorescence when exposed to ultraviolet rays, and can be easily confirmed visually.

[Effect]

The operation of the present invention is as follows.

The quick-drying developer according to the first invention is sprayed or brushed onto the surface of the object to be inspected, which has been subjected to the "pretreatment", "penetration treatment" and "cleaning/removal treatment" in the description of the specific embodiment described above. When applied as a coating and the volatile organic solvent is evaporated, fluorescent dye,
A developer layer made of white inorganic fine powder dyed with a fluorescent brightener is formed.

Since the amount of fluorescent dye and fluorescent brightener used in the formed developer layer is only 9%, the suction effect of the penetrating liquid and the appearance (whiteness) under visible light are similar to that of the well-known "quick-drying type development". "agent"
In other words, there is no difference from a quick-drying developer that does not use fluorescent dyes or fluorescent brighteners, so the "development process" is carried out without any problems, and the indicated pattern appears on the surface of the developer layer. Under visible light, the indicator pattern has a good contrast of red on a white background, and by visually observing it under visible light, the presence/absence and size of a defect can be easily detected. 0 After the above tests are completed, the surface of the object to be inspected is irradiated with an ultraviolet lamp during "post-treatment", and the irradiated ultraviolet light causes the white inorganic fine powder to be dyed with fluorescent dyes and fluorescent brighteners. Since each grain emits fluorescence, its presence can be easily confirmed visually. Therefore, the developer layer can be removed as much as possible from the surface of the object to be inspected by carrying out the removal operation until no fluorescence is visually observed on the surface of the object to be inspected.

In addition, when exposed to ultraviolet rays in a place bright enough to carry out the above-mentioned process and removal of the developer layer, it emits fluorescent light that can be easily confirmed visually. When irradiated, the fluorescence is strongly perceived visually, making it possible to make a more rigorous judgment as to whether or not the developer layer has been completely removed.

〔Example〕

Example 1 Preparation of developer: 6% by weight of fine magnesium carbonate powder with a particle size of about 2 microns, 5% by weight of fine silicic acid powder with a particle size of about 2 microns, 74% by weight of ethyl alcohol, and 15% normal heptane. For every 100 parts by weight of the dispersion obtained by dispersing the mixed liquid, 1 part by weight of an azo fluorescent dye (DON'N YELLOW) (trade name: manufactured by Dyflo Color) and 0.005 parts by weight of a coumarin-based fluorescent whitening agent ( $427: Product name: Asahikayaku/manufactured by) 0.03
parts by weight were added and dissolved by stirring at room temperature for 5 minutes to obtain the intended quick-drying developer.

Removal of developer layer: Using a "2024 S aluminum plate baking crack test piece for penetrant testing (aluminum plate with fine baking cracks on the surface)" as the object to be inspected, clean the surface. After pre-treatment, use a commercially available solvent-removable dye penetrant (
UP-T: Product name: Special Paint Co., Ltd.) is applied and left for 5 minutes for "penetration treatment," and then a commercially available cleaning solvent (tJR-T: Product name: Special Paint Co., Ltd.) is applied to the surface to be inspected. After performing a "cleaning process" to remove excess penetrating liquid from the surface of the object, a "developing process" is performed in which the above-mentioned quick-drying developer is sprayed onto the surface to form a developer layer approximately 10 microns thick. Next, when the surface of the developer layer was visually "observed" under visible light of about 400 lux, a red defect indicating pattern on a white background was clearly seen on the surface of the layer.

Next, in a room with a brightness of approximately 500 lux, the surface of the object to be inspected was first roughly wiped off with a cloth to remove the developer layer, and then a commercially available ultraviolet lamp (Fludge-Sparcy) was used.
When the surface of the object to be inspected was irradiated with ultraviolet rays using TJVF-80 model (trade name: Special Paint Co., Ltd.), a plurality of spots 7) of fluorescent light were visually confirmed on the surface of the object to be inspected.

Then, while continuing to irradiate with ultraviolet rays, the surface of the object to be inspected was thoroughly wiped with a cloth until no visible fluorescence was observed.

After performing the above "post-processing", just to be sure, in a darkroom,
When the surface of the object to be inspected was irradiated with ultraviolet rays using the above-mentioned ultraviolet lamp, no fluorescence was visually observed on the surface of the object to be inspected.

Example λ・Preparation of developer: 7% by weight of magnesium carbonate powder with a particle size of about 2 microns, 5 weight e4 of fine silicic acid powder with a particle size of about 2 microns, 751ff of ethyl alcohol (%) and 15% by weight of normal hebutane. Azo fluorescent dye (Fluorol 5G: trade name: BAS) is added to 100 parts by weight of the dispersion prepared by dispersing the
0.002 parts by weight (manufactured by F. F.) and a fluorescent brightener (fluoranthene: chemical name) were added and dissolved by stirring for 5 minutes at room temperature to obtain the intended quick-drying developer.

Removal of developer layer: Using a threaded part on the outer periphery of a 2-inch diameter iron pipe as the object to be inspected, after performing "pretreatment" to clean the threaded part, use a commercially available solvent-removable dye penetrating solution. (UP-ST:
Product name: Special paint) on approximately half the circumference of the threaded part (inspection surface)
``Penetration treatment'' is performed by applying it to the surface of the surface and leaving it for 5 minutes.Next, ``cleaning treatment'' is performed to remove excess penetrant liquid from the inspection surface using a commercially available cleaning solvent (TJR-8T: product name: Special Paint Co., Ltd.). After that, the above-mentioned quick-drying developer is sprayed onto the inspection surface to form a developer layer with a thickness of about 30 microns.
After that, the surface of the developer layer is coated with approximately 400%
When visually "observed" under the visible light of Lux, a red defect indicator pattern on a white background was clearly seen on the surface of the layer.

Next, in a room with a brightness of approximately 300 lux, the surface to be inspected was first roughly wiped with a cloth to wipe off the developer layer, and then the surface to be inspected was irradiated with ultraviolet light using the same ultraviolet lamp as in Example 1. , multiple spots of fluorescent light were visually confirmed on the inspected surface. Then, with continued ultraviolet irradiation,
Thoroughly wipe the surface of the object to be inspected with a cloth until no spot-like fluorescence can be observed by visual inspection. After performing the above "post-treatment," just to be sure, the surface to be inspected was cleaned in the same manner as in Example 1. When I observed it, there was no visible fluorescence at all.

〔effect〕

According to the present inventions (first invention and second invention) explained above, there is a problem in the "post-processing" in the case where the "dye penetrant test" method and the "quick-drying developer" are combined. It is possible to remove the developer layer from the surface of the object to be inspected while easily visually checking the removal status, and it is also possible to check whether the developer layer has been completely removed, which was previously difficult even for experienced workers. This determination can also be easily made.

Furthermore, even if the work site where the removal work is performed is a dim place with insufficient light, the removal work and the above-mentioned determination can be easily performed.

Claims (2)

[Claims] (1) A dye penetrant test plate prepared by dispersing white inorganic fine powder in a volatile organic solvent and dissolving 0.1% by weight or less of a soluble fluorescent dye and/or fluorescent whitening agent in the solvent. Dry developer. (2) Dispersing white inorganic fine powder in a volatile organic solvent on the surface of the test object, and dispersing a fluorescent dye or/and
A white inorganic material dyed with a fluorescent dye and/or a fluorescent brightener by applying a quick-drying developer for dye penetrant testing containing 0.1% by weight or less of a fluorescent brightener and a fluorescent brightener dissolved therein. A developer layer made of fine powder is formed, and when the developer layer is removed after the dyeing flaw detection test, the surface of the object to be inspected is irradiated with an ultraviolet lamp, and the surface of the object to be inspected is excited by the irradiated ultraviolet light. until no fluorescence is visually observed on the surface of the object to be inspected.
A method for removing a quick-drying developer for dye penetrant testing, which is characterized by carrying out a removal operation.