JP2018179659A - Penetrant for permeability flaw detection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a penetrant for permeability flaw detection enabling the permeability flaw detection even if an inspection object is wet.SOLUTION: In a penetrant for permeability flaw detection obtained by mixing at least a fluorescent dye and a surfactant in a volatile organic solvent, the surfactant containing the penetrant for the permeability flaw detection selects the surfactant having characteristics to be insoluble in water and dispersed in the water. Further, a water-repellent agent is added to the penetrant for the permeability flaw detection. Consequently, the volatile organic solvent is evaporated, and the penetrant for the permeability flaw detection is self-concentrated so that the permeating fluid deposited is hard to mix with the water and difficult to flaw out due to rain water. Hence, the permeability flaw detection is enabled even when an inspection object is wet.SELECTED DRAWING: None

Description

  The present invention relates to a penetrant for penetrant test which is used to detect fine scratches formed on the surface of a material.

Conventionally, penetration flaw detection inspection is performed as one method of nondestructive inspection (for example, refer to patent documents 1.).
In the penetrant inspection, the penetrant for penetrant inspection is applied to the surface of the material to be inspected, etc., and the penetrant for penetrant inspection is impregnated in fine flaws that can not be visually recognized by the naked eye. After removing the penetrant solution for penetrant test that remained on the surface, the penetrant solution for penetrant test which has been infiltrated into the flaw is developed by drawing it out to the material surface to make it visible or make it possible to penetrate the flaw. The fluorescent substance contained in the penetration liquid is made to emit light with a black light so as to be visible, and the presence or absence of a scratch is observed.

Japanese Patent Application Laid-Open No. 3-45786

However, when the inspection object is outdoors, the penetration inspection can not be performed at the time of rainy weather.
This is because even if the penetrant for penetrant test is applied to the surface of the material to be inspected, it may be washed away by rainwater, or if there is rainwater inside the wound, the penetrant for penetrant test may soak into the wound. Because it can not do a predetermined inspection.
Therefore, there is a problem that if the object to be inspected gets wet during the penetration inspection, the inspection must be stopped at that point.

  An object of the present invention is to provide a penetrant for penetrant inspection which enables penetrant inspection even if the object to be inspected is wet.

In order to achieve the above object, the present invention is
It is a penetrant for penetrant testing, comprising at least a fluorescent dye and a surfactant mixed in a volatile organic solvent,
The surfactant is insoluble in water and has the property of being dispersed in water.

The penetrant solution for penetrant flaw detection is applied to the surface of the material to be inspected, and 50% by weight or more of the volatile organic solvent evaporates, and the penetrant fluid for penetrant flaw detection is self-concentrated, a penetrant fluid such as a fluorescent dye or surfactant The components come to precipitate.
Then, since the surfactant contained in the permeated liquid component that is self-concentrated and precipitated is insoluble in water and has a property of being dispersed in water, the self-concentrated permeated liquid component is water and Because it is difficult to mix and it is difficult for it to flow out due to rain water etc., penetrant inspection is possible even when the object to be inspected is wet.
For example, in the case of a penetrant containing a water-soluble surfactant, the self-concentrated penetrant component is likely to be miscible with water, and it may be drained by rainwater or the like. In addition, in the case of a penetrant containing a surfactant that gelates by mixing with water, the fluidity of the self-concentrated penetrant component extremely decreases and the permeability into the interior of the fine wound decreases. It is unsuitable for penetrant inspection when the inspection object is wet.
On the other hand, if it is a penetrant for penetrant flaw detection which contains a surfactant which is insoluble in water and has a property of being dispersed in water, penetrant flaw inspection is carried out even if the inspection object is wet. It will be possible to do.

Also preferably,
The proportion of the surfactant in the penetrant for penetrant flaw detection is set to 5% by weight or more and 20% by weight or less.
For example, if the proportion of the surfactant in the penetrant for penetrant flaw detection is less than 5% by weight, the amount of penetrant components deposited on the surface of the material by self-concentration is small, so the penetrant flaw detection accuracy decreases. There is a fear.
In addition, when the ratio of the surfactant to the penetrant for penetrant flaw detection reaches a high concentration exceeding 20% by weight, the penetrant fluid for penetrant flaw may freeze and become unusable in a low temperature environment.

Also preferably,
The HLB value of the surfactant is set to 8 or less.
The HLB value is a value representing the degree of affinity of the surfactant to water and oil, and takes a value of 0 to 20. The closer to 0, the higher the lipophilicity, and the closer to 20, the higher the hydrophilicity.
Since the surfactant contained in the penetrant for penetrant flaw detection of the present application preferably has a low affinity to water, a surfactant having an HLB value of 8 or less was used.

Also preferably,
A water repellent is added to the penetrant for penetrant flaw detection.
By doing this, water permeability is imparted to the self-concentrated penetrant component of the penetrant for penetrant test, and the self-concentrated penetrant component becomes more difficult to be mixed with water, and therefore the penetrant liquid due to rain water etc. It is possible to further reduce the outflow of the components.

  According to the present invention, penetrant inspection can be performed even if the inspection object is wet.

  Hereinafter, an embodiment of a penetrant for penetrant flaw detection according to the present invention will be described in detail. However, although various limitations which are technically preferable for carrying out the present invention are given to the embodiments described below, the scope of the present invention is not limited to the following embodiments.

The penetrant solution for penetrant flaw detection of the present embodiment is a penetrant liquid for fluorescent penetrant flaw detection used for fluorescence penetrant flaw detection.
In the fluorescent penetrant test, the penetrant solution for fluorescent penetrant flaw detection is applied to the surface of the material to be inspected, the penetrant fluid is infiltrated into the minute flaws produced on the material surface, and the penetrant fluid remaining on the surface is removed. This is a method of nondestructive inspection in which a fluorescent dye contained in a penetrant soaked in a flaw is made to emit light visibly by a black light to inspect the presence or absence of a flaw.

  In particular, the penetrant for penetrant flaw detection according to the present embodiment enables penetrant flaw detection even when the test target is wet, and for example, rain may come out during penetrant flaw detection in the outdoors, and the test target is wetted Also, even if the test object is wet because it is a penetrant test that will be carried out shortly after the rain, it will enable that test.

Specifically, the penetrant solution for penetrant flaw detection according to the present embodiment is a penetrant fluid for penetrant flaw detection obtained by mixing at least a fluorescent dye and a surfactant in a volatile organic solvent, and the interface contained in this penetrant fluid. The surfactant was selected from among various surfactants, which were insoluble in water and had properties of being dispersed in water.
When a penetrant for penetrant flaw detection containing a surfactant having such properties is applied to the surface of the material to be inspected, 50% by weight or more of the volatile organic solvent evaporates, and the penetrant fluid for penetrant flaw is self-concentrated. The present inventors have found that the permeated liquid component that is self-concentrated and deposited on the surface is unlikely to flow out due to rain water or the like.

In the case of a penetrant containing a water-soluble surfactant, the self-concentrated penetrant component tends to be miscible with water, and it may flow out due to rain water or the like. In addition, in the case of a penetrant containing a surfactant that gelates by mixing with water, the fluidity of the self-concentrated penetrant component extremely decreases and the permeability into the interior of the fine wound decreases. It is unsuitable for penetrant inspection when the inspection object is wet.
On the other hand, if it is a penetrant for penetrant flaw detection that contains a surfactant that is insoluble in water and has a property of being dispersed in water, the self-concentrated penetrant component is difficult to mix with water, and rainwater Since it is difficult for the fluid to flow out, penetrant inspection is possible even when the object to be inspected is wet.

The proportion of the surfactant in the penetrant for penetrant flaw detection was set to 5% by weight or more and 20% by weight or less.
If the proportion of surfactant in the penetrant for penetrant flaw detection is less than 5% by weight, the amount of penetrant components deposited on the surface of the material by self-concentration may be small, so the accuracy of penetrant flaw detection may be reduced. is there.
On the other hand, if the proportion of surfactant in the penetrant for penetrant flaw detection exceeds 20% by weight and the concentration of the surfactant becomes high, the penetrant fluid for penetrant flaw detection may freeze and become unusable in a low temperature environment . This upper limit is set because there is a limitation that the penetrant for penetrant flaw detection is a test liquid that can be used even in an environment of minus 15 ° C.

Moreover, it is preferable that the HLB value of the surfactant which the penetrant for penetrant flaw detection of this embodiment contains is 8 or less.
The HLB (Hydrophilic-Lipophilic Balance) value is a value representing the degree of affinity of the surfactant for water and oil. The HLB value takes a value of 0 to 20, and the closer to 0, the higher the lipophilicity, and the closer to 20, the higher the hydrophilicity.
As the surfactant contained in the penetrant for penetrant test of the present embodiment is preferably one having a low affinity to water, it is decided to use a surfactant having an HLB value of 8 or less.

Further, a water repellent agent is added to the penetrant solution for penetrant flaw detection of the present embodiment.
When a water repellent is added to the penetrant for penetrant flaw detection, the penetrant component for penetrant flaw detection is imparted with water repellency to the penetrant liquid component that is self-concentrated, and the self-concentrated penetrant component is further concentrated on water. Since it becomes difficult to mix, it is possible to further reduce the outflow of the penetrant component due to rain water or the like.

  Further, in the penetrant for penetrant flaw detection according to the present embodiment, a hydrophilic fluorine-based additive is used to reduce the surface tension of the mixed liquid when water in a fine flaw and the penetrant before concentration are mixed. In addition. This is because, if the surface tension of the mixture is high in the water inside the wound or in the mixture of the water remaining on the inspection surface and the permeation liquid before concentration, it is difficult to suitably penetrate the inside of the wound. is there.

  Next, various components used to prepare the penetrant solution for penetrant flaw detection of the present embodiment and the blending thereof will be described.

(Volatile organic solvent)
Mix ethanol NH (made by Yamaichi Chemical Industry Co., Ltd.) and n-propanol (made by Yamaichi Chemical Industry Co., Ltd.) were used for the volatile organic solvent.

(Fluorescent dye)
As a fluorescent dye, Nikkafluor MCT (manufactured by Nippon Chemical Industrial Co., Ltd.), OPLAS YELLOW 156 (manufactured by Orient Chemical Co., Ltd.), and Uraninconc (manufactured by Toka Kasei Co., Ltd.) were used.

(Surfactant)
Newcoal 3-80 (manufactured by Nippon Emulsifier Co., Ltd.) was used as the surfactant.

(Water repellent)
As a water repellent, KBM-7103 (manufactured by Shin-Etsu Chemical Co., Ltd.) was used.

(Additive)
As the additives, Surfynol 440 (manufactured by Nisshin Chemical Industry Co., Ltd.) and Surfron S-243 (manufactured by AGC Seimi Chemical Co., Ltd.) were used.

  As shown in Table I, the penetrating liquid for penetrant flaw detection containing 5% by weight of Newcol 3-80 (surfactant) in Example 1; 10 in Newcor 3-80 (surfactant) in Example 2 A penetrant penetrant for penetrant test was prepared, in which 20% by weight of penetrant for penetrant test was mixed, and in Example 3, Neucor 3-80 (surfactant) was mixed.

  The penetrant for penetrant flaw detection in Examples 1 to 3 was used as a type 1 contrast test piece (two types of flaw depth 30 μm and 50 μm) and a type 3 contrast test piece of the contrast test piece defined in JIS Z 2343, respectively. After applying while irradiating with a light and leaving for 2 minutes, excess penetrant remaining on the test surface was wiped off with a rag to remove. Thereafter, the excess permeation liquid remaining on the surface was further wiped off with a rag impregnated with the removal liquid, and it was tested whether or not it was possible to observe the presence or absence of a scratch.

  First, assuming use in midsummer and midwinter, as the environmental temperature test, in the environmental test room where control can be performed at a constant temperature, the material temperature of the test piece is used under the condition of minus 15 ° C to plus 60 ° C A test was conducted to see if it was possible. At a test temperature of minus 15 ° C., water was applied to the test piece by water spray as simulated snow, and after 1 hour, the test was carried out from a state in which an ice film was stretched on the surface of the test piece. In an environment of plus 60 ° C., even if moisture is applied under the environment of plus 60 ° C., the moisture evaporates, so the test piece is immersed for 1 hour in the moisture kept at 60 ° C. in a thermostatic chamber and then tested Carried out.

In the use at normal temperature, tests were conducted under the assumption of simulated rainfall under the temperature environment of plus 20 ° C., using the type 1 contrast test piece and the type 3 contrast test of the contrast test piece described above. In particular, a heating and pressurizing apparatus was used under conditions where simulated rainfall was assumed. The heating and pressurizing apparatus is an apparatus in which a pump and a tank having a heat source are provided side by side so that pressurization and heating can be performed, and adjustment of water pressure and water temperature can be freely performed. The water temperature was maintained at a temperature of plus 20 ° C., and the water pressure was set so that water of a constant water pressure was blown out concentrically from the spray nozzle by using a pressure gauge.
In particular, the numerical value of the pressure gauge simulates the amount of precipitation while keeping the pressure constant because the water injection amount changes due to the water pressure. The calculation method of precipitation was based on the principle of rainfall observation announced by the Japan Meteorological Agency. In simulated rainfall, water pressure adjustment is performed on calculation 2 conditions of 5 mm / 1 hour and 10 mm / 1 hour, and type 1 contrast test pieces (2 types of flaw depth 30 μm and 50 μm) and type 3 contrast test in washing booth The piece was placed, and water adjusted to the water pressure under the above two conditions was jetted for 1 hour. This is because, in fact, the rails of the railway track in rainy weather are always exposed to rain, especially in the open air, and since water is contained in the wound, even in simulated rainfall, water is permeated into the wound as well. Injected for 1 hour to After that, assuming rain, pre-treatment with a washing solution was performed in a state where water was kept jetted, and coating was performed while irradiating black light. In the subsequent steps, in the actual site, it is difficult to move to the next step after exactly 2 minutes of application of the penetrant, and it may take a considerable amount of time while performing other operations. Conceivable. Therefore, in this simulated rainfall test, it was assumed that water was jetted for 30 minutes after the application of the penetrant, and that it was exposed to rain for 30 minutes after the penetrant was applied. After spraying the water for 30 minutes, the excess permeate remaining on the test surface is wiped off with a rag to remove it, and then the excess permeate remaining on the surface is further wiped off with a rag impregnated with the remover, and there is no damage. It was tested whether it was possible to observe

  In the evaluation of the test results, the evaluation was performed with reference to JIS Z 2343. In the dye penetration test used as the current method, the sensitivity level is graded according to JIS Z 2343-2, and the sensitivity level of the dye penetration solution is 50 μm and 30 μm flaw detection rate of the type 1 contrast test piece. It has been decided. The sensitivity level of the staining penetrant currently used is sensitivity level 2 (high sensitivity). With respect to sensitivity level 2, a flaw detection rate of 100% is required for 50 μm of the comparison test piece and 75% or more for 30 μm. Therefore, even in the case of the penetrant, the flaw detection rate of the type 1 contrast test specimen is 100% for 50 μm and 75% or more for 30 μm, so that the sensitivity level is equal to or higher than that of the dye penetration test. Visual evaluation was performed to see if it could be done.

  As a result of conducting this test, in any of the penetrant liquids for penetrant flaw detection in Examples 1 to 3, the fluorescent penetrant flaw detection test shows rainfall of up to 5 mm / 1 hour in the range from minus 15 degrees C. to plus 60 degrees C. In this case, the flaw detection rate of 50 μm was 100% and that of 75 μm or more was confirmed at 30 μm in the flaw detection rate of the type 1 contrast test piece, so that the inspection can be suitably performed equal to or more than the current stain penetration test. Was confirmed.

As described above, in the case of the penetrant for penetrant flaw detection of the present embodiment, penetrant flaw inspection can be suitably performed even if the inspection object is wet.
That is, even if the object to be inspected is wet because it rains during outdoor penetrant inspection and the object to be inspected is wet because it is a penetrant inspection performed immediately after the rain, the penetrant for penetrant inspection according to this embodiment By using a liquid, penetrant inspection can be suitably performed.

For example, penetrant inspection has been performed as a nondestructive inspection of the rails of a railway track so far, but since the range in which the rails are installed is long-distance, the inspection requires a long time. In addition, because there are many areas where the rails are laid outdoors, the inspections are susceptible to the weather.
As a result, the weather changes during the penetration inspection and it starts raining, and at that point it is necessary to stop the inspection. In addition, although the probability of precipitation is low, if there is an indication that it is likely to start raining, it may have been determined whether to start penetrant inspection or to postpone the inspection to avoid suspension or interruption due to rainfall.
Conventionally, there have been the above-mentioned problems in conducting penetrant inspection of rail rails, but if it is the penetrant for penetrant inspection of this embodiment, rain will come out during penetrant inspection and the inspection object will get wet Even if it does, it will be possible to continue the penetrant inspection.
Thus, the penetrant for penetrant flaw detection of the present embodiment is suitable for performing penetrant flaw inspection of a rail of a railway laid outdoors.

In the above embodiment, the case where Neucor 3-80 (manufactured by Nippon Emulsifier Co., Ltd.) is used as a surfactant which is insoluble in water and has a property of being dispersed in water is described as an example. Also, DMH-20 (manufactured by Nippon Emulsifier Co., Ltd.) can be used as a surfactant having similar properties.
Also, a mixture of Nycor 3-80 and DMH-20 may be used as a surfactant.

  The application of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

Claims (4)

It is a penetrant for penetrant testing, comprising at least a fluorescent dye and a surfactant mixed in a volatile organic solvent,
The penetrant for penetrant flaw detection characterized in that the surfactant is insoluble in water and has a property of being dispersed in water.   The penetrant fluid for penetrant flaw detection according to claim 1, wherein a ratio of the surfactant in the penetrant fluid for penetrant flaw detection is 5% by weight or more and 20% by weight or less.   The penetrant for penetrant flaw detection according to claim 1 or 2, wherein the HLB value of the surfactant is 8 or less. A penetrant for penetrant flaw detection according to any one of claims 1 to 3, wherein a water repellent is added to the penetrant for penetrant flaw detection.