JPH0551095B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a high-sensitivity washable fluorescent penetrant liquid for high temperatures used in a washable fluorescent penetrant testing method.

[Conventional technology]

As is well known, non-contact technology is used to detect surface opening defects (hereinafter referred to as "defects") such as minute cracks and minute pits that exist on the surfaces of mechanical parts made of metals, plastics, ceramics, etc. One type of destructive testing method is the penetrant testing method standardized in "JIS Z 2343-1982."

As shown in the above JIS standard, penetrant testing methods are classified in detail according to the type of penetrant used, the type of development method, the type of cleaning method, etc. In the JIS standards listed above, there are test methods indicated by "Test method symbol: FA-D" and test methods indicated by "Test method symbol: FA-N."

The former test method indicated by "FA-D" involves applying a water-washable fluorescent penetrating liquid to the test surface of the object to be inspected by dipping, brushing, or other means, and leaving it for a predetermined period of time to remove defects. After the penetrating liquid remains on the test surface without penetrating into the defective part, wash it with water to remove it. After drying the test surface, remove the excess penetrant that remains on the test surface without penetrating into the defective part. Since it is difficult to observe the presence of the penetrating liquid in the defect, a developer made of white inorganic fine powder is applied to the test surface to form a layer of white inorganic fine powder on the test surface, and this layer allows the penetrating liquid in the defect to be absorbed. After making a defect indicator pattern appear on the layer surface by sucking it out, the test surface is visually observed under irradiation with an ultraviolet light (black light), and the defective area is determined by the fluorescent defect indicator pattern on the test surface. This is a test method that detects presence and location.

The latter test method indicated by "FA-N" is the same as the former until the excess penetrant is removed by washing with water, but after that, unlike the former, the test surface is dried by heating. After developing a defect indicator pattern on the test surface by causing the penetrant in the defect to expand and ooze out onto the test surface (usually by hot air drying), an ultraviolet lamp is used without the application of a developer. This is a test method in which the test surface is visually observed under irradiation with black light, and the existence and position of defects are detected by the fluorescent defect indicator pattern on the test surface.

The basic composition of the washable fluorescent penetrating liquid used in both of the above test methods is described in "Nondestructive Testing Handbook [New Edition], edited by the Japan Nondestructive Testing Association, published by Nippon Kogyo Shimbun, April 28, 1970, P717. ``2.1.1 Composition of penetrating liquid''
As shown in Figure 2, it consists of a fluorescent dye, a solvent, and a surfactant.In order to obtain the fluorescent brightness necessary for detecting defects, the solvent dissolves the fluorescent dye and makes it permeable. The surfactant is formulated to self-emulsify with water and make it washable. In addition to these three components, a component called a base agent is usually blended to improve the wettability of the liquid and to exhibit stronger fluorescence brightness.

The following are specific examples of what has conventionally been used as the above-mentioned four components.

Fluorescent dyes include naphthalimide-based oil-soluble fluorescent dyes such as Hudson Yellow (product name: Dai-Glo Color Co., Ltd.) and Flawless Scent Yellow FIH (product name: Silado Chemical Co., Ltd.) - coumarin-based oil-soluble fluorescent dyes such as white. Fluoro G (product name: Sumitomo Chemical) and Keikol E (product name:
Nisso Kako Co., Ltd.) - Fluorescein-based oil-soluble fluorescent dye - For example, Fluorol 5G (Product name: BASF
)-, benzotriazole-based oil-soluble fluorescent dye-
For example, #427 (product name: Nippon Kayaku Co., Ltd.) - pyrazoline oil-soluble fluorescent dyes - such as Kikol C (product name: Nisso Kako Co., Ltd.) - acenaphthene oil-soluble fluorescent dyes - such as fluoranthene (chemical name) )-, etc., one or more types of oil-soluble fluorescent dyes are used.

Examples of solvents include glycol ethers such as diethylene glycol monobutyl ether, hydrocarbons such as benzene and xylene, and petroleum such as R-100 (product name: Nippon Petrochemicals) and R-150 (product name: Nippon Petrochemicals). One or more types of solvents are used.

As the surfactant, nonionic surfactants and anionic surfactants are used.

As base agents, plasticizers such as dioctyl phthalate (DOP), diethyl phthalate (DEP), butal phthalyl butyl glycolate (BPBG), and vegetable oils such as soybean oil and castor oil are used.

The water-washable fluorescent penetrating liquid consists of the four components described above, and the water-washable fluorescent penetrating liquid used in the latter test method, specifically, the test method that does not use a developer and is designated by "FA-N". Fluorescent penetrant is especially called "high-sensitivity water-washable fluorescent penetrant", and because no developer is applied, it has high fluorescence brightness and the penetrant does not easily flow into defective areas when washed with water. is required, and the former test method, more specifically, the water-washable fluorescent penetrant liquid (hereinafter referred to as
(referred to as "general water washable fluorescent penetrant liquid"),
High-sensitivity water-washable fluorescent penetrant liquid contains more oil-soluble fluorescent dye and more base solvent to ensure higher fluorescence brightness, and ensures easy washing with water even when a large amount of these is blended. In order to do this, more surfactants are blended, and nonionic surfactants, especially polyethylene glycol type nonionic surfactants, are used to ensure that the penetrating liquid in the defect area does not flow easily when washed with water. .

Typical formulations of conventional general water-washable fluorescent penetrant liquids and conventional high-sensitivity water-washable fluorescent penetrant liquids are as follows.

Formula for general water-washable fluorescent penetrant liquid Oil-soluble fluorescent dye: 0.1 to 0.5% by weight Solvent: 60 to 80% by weight Surfactant (nonionic surfactant, anionic surfactant): 5 to 10% by weight Base agent: 5-10% by weight Highly sensitive water-washable fluorescent penetrant liquid formulation Oil-soluble fluorescent dye: 1-7% by weight Solvent: 30-60% by weight Surfactant (polyethylene glycol type nonionic surfactant): 10-40% by weight Base agent: 10-30% by weight As far as the present inventor is aware, only polyethylene glycol type is actually used as a nonionic surfactant used in highly sensitive water-washable fluorescent penetrant liquid. The polyhydric alcohol type is not used because its cleaning properties are extremely weak. Commonly used polyethylene glycol type nonionic surfactants are polyoxyethylene nonyl phenyl ether and polyoxyethylene octyl phenyl ether having an HLB of about 10 to 16.

Furthermore, in the industry, it is considered taboo to use anionic surfactants in high-sensitivity water-washable fluorescent penetrating liquids, because using anionic surfactants will make the cleaning properties too strong and cause defects during washing. This is because most of the penetrating liquid in the part is washed away, making it impossible to detect the defective part. It has been confirmed that it was impossible to detect scratches on the

[Problem that the invention seeks to solve]

"FA-N" uses highly sensitive water-washable fluorescent penetrating liquid
The test method described above is extremely efficient because it does not use a developer, and is suitable for continuous flaw detection of a large number of test objects, for example, for inspecting parts in an automobile assembly plant. however,
This test method has the disadvantage that if the temperature of the test object is approximately 50℃ or higher, especially 80℃ or higher, it cannot be applied unless the temperature of the test object is lowered to 50℃ or lower. . In other words, when this test method is applied to an object to be inspected that is maintained at a high temperature of about 50°C or higher, for example, about 70°C after being thermally processed, it will not penetrate into the defective part. When removing excess penetrant remaining on the test surface by washing with water, it was not possible to remove the excess penetrant sufficiently, and some of the excess penetrant remained on the test surface. When the test surface is visually observed under ultraviolet lamp irradiation, the fluorescence from the excess penetrant remaining on the test surface appears as an afterglow along with the fluorescent defect indicator pattern, resulting in a marked decrease in flaw detection accuracy and extreme In such cases, flaw detection becomes impossible.

The reason for the above drawback is that when the conventional highly sensitive water-washable fluorescent penetrant liquid represented by the above formulation comes into contact with an object to be inspected at a temperature of approximately 50°C or higher, its water-washability deteriorates significantly. be.

Therefore, conventionally, the test method indicated by "FA-N", which uses a highly sensitive water-washable fluorescent penetrant, has been used for approximately 50
When applied to objects to be inspected that are at high temperatures of 80°C or higher, in particular, it is necessary to wait for the temperature of the object to be inspected to drop to about 50°C or lower, or to install cooling equipment. Such waiting time or cooling costs are
This is a serious loss that cannot be ignored.

The technical objective of the present invention is to solve the above problems.

[Means for solving problems]

The present inventor has solved the above-mentioned problems by providing a highly sensitive water-washable fluorescent penetrant liquid whose washability does not deteriorate even when it comes into contact with a test object at a high temperature of about 50°C or higher, especially 80°C or higher. This is what I did. That is, the present invention uses 1 to 7% by weight of an oil-soluble fluorescent dye and 30 to 7% by weight of its solvent.
60% by weight, 10-40% by weight of polyethylene glycol type nonionic surfactant and 10-40% by weight of plasticizer or vegetable oil.
This is a high-sensitivity, water-washable fluorescent penetrant liquid for high temperature use, characterized in that 0.5 to 2% by weight of dialkyl sulfosuccinate is added to a highly sensitive water-washable fluorescent penetrant liquid consisting of 30 weight percent.

The highly sensitive water-washable fluorescent penetrant for high temperature use (hereinafter referred to as "the product of the present invention") according to the present invention is obtained by adding a specific amount of dialkyl sulfosuccinate to the above-mentioned formulation of the conventional high-sensitivity water-washable penetrant. be.

That is, the oil-soluble fluorescent dye, solvent, and base agent in the product of the present invention are all those mentioned above as specific examples, and the surfactant is a polyethylene glycol type nonionic surfactant. Furthermore, the proportions of the oil-soluble fluorescent dye, solvent, polyethylene glycol type nonionic surfactant, and base agent are the same as in the above-mentioned formulation of the conventional highly sensitive water-washable fluorescent penetrant liquid.

The dialkyl sulfosuccinate in the product of the present invention is a type of anionic surfactant,
It is commercially available. The amount of this substance added is important, and it is added in the range of 0.5 to 2.0% by weight. 0.5% by weight
In the following cases, the desired water washability cannot be obtained and excess permeate cannot be removed sufficiently. If the amount is 2.0% by weight or more, the cleaning properties will be too strong and an over-cleaning phenomenon will occur in which not only the excess penetrant but also the penetrant in the defect area will be washed away. If added within the range of 0.5 to 2.0% by weight, the product of the present invention
℃ or higher, especially when it comes into contact with a high-temperature inspection object of 80℃ to 100℃, it is possible to sufficiently remove excess penetrant and prevent over-cleaning, allowing highly accurate flaw detection. Guaranteed.

The product of the present invention can be easily prepared by simply stirring a mixture of predetermined amounts of the four components and a predetermined amount of dialkyl sulfosuccinate, and heating and stirring as necessary.

[Effect]

The effects of the product of the present invention, together with its usage, are as follows.

First, the product of the present invention is attached to the test surface of the object to be inspected, which has been maintained at a high temperature of approximately 90° C. through a thermal processing process. In this case, the object to be inspected is usually immersed in a tank filled with the product of the present invention and then pulled up to make the product adhere to the defect. Even after being left for about 5 minutes for penetration, the temperature of the object to be inspected remains at about 70°C to 80°C or higher. Next, the excess product of the present invention remaining on the test surface without penetrating into the defect is removed by washing with water. In this case, cleaning is usually carried out by water spray for 30 to 60 seconds at a spray pressure of 1 kg/cm ² . After cleaning, the test surface is heated and dried. In this case, drying is usually done by blowing hot air at 60°C to 70°C onto the test surface. Finally, as usual, the test surface is visually observed under black light irradiation to confirm the presence of a fluorescent defect indicator pattern on the test surface, thereby detecting the presence and location of the defect.

In the usage mode as described above, the product of the present invention has approximately
It adheres to the test object at 90℃, remains attached to the test object at about 80℃ for about 5 minutes, and even when washed with water, it remains attached to the test object at about 70℃. First, the surplus of the present invention product remaining on the test surface can be sufficiently removed, no over-cleaning phenomenon occurs, and even minute defects can be detected with high precision.

On the other hand, in the case of a formulation in which the dialkyl sulfosuccinate is removed from the formulation of the product of the present invention, in other words, in the case of a conventional high-sensitivity water-washable fluorescent penetrant, when used under the same conditions as the above-mentioned usage pattern, excessive penetration occurs. When the liquid was not removed sufficiently, the fluorescence of the excess penetrating liquid remaining on the test surface appeared as an afterglow when the test surface was visually observed under irradiation with an ultraviolet lamp, making it difficult to distinguish between the afterglow and the fluorescent defect indicator pattern. This makes it extremely difficult.

This difference is due to the presence of a certain amount of dialkyl sulfosuccinate, but the theoretical elucidation of its effect is still unclear. However, when conventional high-sensitivity water-washable fluorescent penetrant liquids come into contact with test objects at temperatures above 50°C, their water-washability deteriorates due to the polyethylene glycol type nonionic surfactant in the formulation. This is because the agent becomes difficult to dissolve in water at temperatures above about 50°C, and it is clear that the presence of dialkyl sulfosuccinate compensates for the deteriorated water washability. The present inventor found that even with the same anionic surfactant, for example, when calcium dodecylbenzenesulfonate was added to the formulation, no effect of improving water washability was observed. In the formulation of water-washable fluorescent penetrating liquid, it acts specifically to compensate for the deterioration of water-washability at high temperatures, and when the amount is appropriate, the gelling ability of the polyethylene glycol type nonionic surfactant in the formulation It is believed that this method does not cause over-cleaning phenomenon because it does not inhibit the process.

〔Example〕

Next, the present invention will be explained in detail using Examples and Comparative Examples.

Example 1 Preparation of the product of the present invention: 3.5% by weight of a naphthalimide-based oil-soluble fluorescent dye (Hudson Yellow, trade name: manufactured by Daiklo Color Co., Ltd.) and a benzotriazole-based oil-soluble fluorescent dye (#427: trade name) as an oil-soluble fluorescent dye. : 1.5% by weight (manufactured by Nippon Kayaku), 10% by weight of alkylbenzene and 10% by weight of diethylene glycol monobutyl ether as solvents, and 20% by weight of a petroleum-based mixed solvent (Hotsukusolben, product name: manufactured by Nippon Petrochemical), polyethylene. 30% by weight of polyoxyethylene nonyl phenyl ether (HLB: 12.8) was used as a glycol-type nonionic surfactant, 25% by weight of dioctyl phthalate (DOP) was used as a plasticizer, and dialkyl sulfosuccinate was used.
0.5% by weight was used.

The above components were mixed and sufficiently stirred to prepare the product of the present invention.

Washable Fluorescent Penetrant Flaw Detection Test: The aforementioned JIS standard "B type comparative test piece" was heated to 90°C, and the above-mentioned product of the present invention was applied to the test surface with a brush, and left for 5 minutes. The temperature of the test piece at this time was 80°C.

Next, the test surface was sprayed with a spray pressure of 1 Kg/cm ² for approximately 30 min.
It was washed with a hot water spray at about 50° C. for seconds. The temperature of the test piece at this time was 60°C.

Next, after drying the test surface by blowing hot air at about 60℃ for about 180 seconds, the test surface was visually observed under black light irradiation according to the usual method, and there was hardly any afterglow. A fluorescent defect indicating pattern was observed, and the fluorescent defect indicating pattern even showed minute scratches on the test surface, and the detection performance was judged to be "good."

Example 2 Same as Example 1 except that the amount of dialkyl sulfosuccinate was 2.0% by weight,
When the product of the present invention was prepared and subjected to a water washable fluorescent penetrant test using it under the same conditions as in Example 1, the test results were also the same as in Example 1.
The detection performance was judged to be "good."

Comparative Example 1 Same as Example 1 except that the amount of dialkyl sulfosuccinate was 3.0% by weight,
When a comparative product was prepared and subjected to a water washable fluorescent penetrant test under the same conditions as in Example 1, no afterglow was observed, but the fluorescent brightness of the fluorescent defect indicator pattern was low. The fluorescent defect indicator pattern did not indicate minute scratches on the test surface, and the detection performance was determined to be "inferior."

Comparative Example 2 A conventional high-sensitivity water-washable fluorescent penetrating liquid was prepared in exactly the same manner as in Example 1, except that no dialkyl sulfosuccinate was used, and this was used to prepare Example 1.
When a water washable fluorescence penetrating deep scratch test was conducted under exactly the same conditions, a lot of afterglow was observed on the test surface, and it was very difficult to distinguish between the afterglow and the fluorescent defect indicator pattern, and the detection performance was poor. It was judged as "defective".

〔effect〕

The product of the present invention as explained above can be used at temperatures above about 50°C.
In particular, even if it is attached to an object to be inspected at a high temperature of 80°C to 100°C, it maintains good water washability during cleaning and does not cause over-cleaning.

Therefore, when performing the test method indicated by "FA-N" using the product of the present invention, there is no need to wait until the temperature of the test object drops to about 50 degrees Celsius or less or cool it, as was the case in the past. It has extremely high efficiency, making it possible to significantly shorten the process and reduce costs.

The product of the present invention can also be used in the test method indicated by "FA-D".

Claims (1)

[Claims] 1 Oil-soluble fluorescent dye 1~7% by weight, its solvent 30~
60% by weight, 10-40% by weight of polyethylene glycol type nonionic surfactant and 10-40% by weight of plasticizer or vegetable oil.
A high-sensitivity water-washable fluorescent penetrant liquid for high temperature use, characterized in that 0.5 to 2 weight % of dialkyl sulfosuccinate is added to a highly sensitive water-washable fluorescent penetrant liquid consisting of 30 weight percent.